This document provides an overview of electronic private automatic branch exchange (EPABX) systems. It discusses the history of PBX systems and how they have evolved from manual switchboards operated by telephone operators to modern digital and IP-based systems. It describes the typical components of an EPABX system, including the switching network, control cards, telephone stations, outside telephone trunk lines, and power supply. Current trends in EPABX technology include the adoption of voice over IP (VoIP) and ISDN systems. The document also briefly discusses the use of small EPABX systems in homes and small businesses.

1. i
A PROJECT REPORT ON
Electronic Private Automatic Branch Exchange
Submitted in partial fulfillment of the requirements for the
award of the degree of
Bachelor of Technology
In
Electronics & Communication Engineering
Submitted by
Ashok Ranjan: 0905431022
Ashutosh Singh: 0905431023
Arshit Srivastava: 0905431019
Jyoti Haveliya: 0905431051
DEPARTMENT OF ELECTRONICS & COMMUNICATION
ENGINEERING
BABU BANARASI DAS NATIONAL INSTITUTE OF
TECHNOLOGY & MANAGEMENT, LUCKNOW
(Affiliated to G. B. Technical University, Lucknow)
SESSION (2012 - 2013)

2. ii
BABU BANARASI DAS NATIONAL INSTITUTE OF
TECHNOLOGY & MANAGEMENT, LUCKNOW
DEPARTMENT OF ELECTRONICS & COMMUNICATION
ENGINEERING
CERTIFICATE
Certified that the project entitled “Electronic Private Automatic Branch Exchange” is
a bonafide work carried out in 8th
semester by “Ashok Ranjan (0905431022),Ashutosh
Singh (095431023),ArshitSrivastava (0905431019),JyotiHaveliya(0905431051)in
partial fulfillment for the award of Bachelor of Technology in “ ELECTRONICS &
COMMUNICATION ENGINEERING ” from G. B. Technical University, Lucknow,
during the academic year 2012- 2013. Who carried out the project work under the
guidance and no part of this work has been submitted earlier for the award of any degree.
PROF.SHAILENDRA TAHILYANI
HEAD OF THE DEPARTMENT
(Electronics and Communication Engineering)
BBDNITM, Lucknow, UP

3. iii
ACKNOWLEDGEMENT
We would like to express our gratitude and sincerely thanks our project guide PROF.
SHAILENDRA TAHILYANI,HOD department of ELECTRONICS &
COMMUNICATION of BBDNITM,Lucknow. It was only under his guidance and
support that we could make this project in running condition. He provided us with all
sorts of technical help and guided us through the entire course of this project.
We express our profound thanks to our teachers who cultivated devotion and
determination in us which have been deep source of wisdom and inspiration for such
initiative. They motivated us to complete our project.
Ashok Ranjan
Ashutosh Singh
Arshit Srivastava
Jyoti Haveliya

4. iv
ABSTRACT
A private branch exchange (PBX) is a telephone exchange that serves a particular
business or office, as opposed to one that a common carrier or telephone company
operates for many businesses or for the general public. PBXs are also referred to as:
 PABX – private automatic branch exchange
 EPABX – electronic private automatic branch exchange
PBXs make connections among the internal telephones of a private organization—usually
a business—and also connect them to the public switched telephone network (PSTN)
via trunk lines. Because they incorporate telephones, fax machines, modems, and more,
the general term "extension" is used to refer to any end point on the branch.
PBXs are differentiated from "key systems" in that users of key systems manually select
their own outgoing lines, while PBXs select the outgoing line automatically. Hybrid
systems combine features of both.

5. v
TABLE OF CONTENT
Abstract iv
List of figures ix
List of tables xi
List of abbreviations xii
Chapter 1 1-9
1.1 EPABX (Electronic Private Automatic Branch Exchange) 1
1.1.1 History 1
1.1.2 System components 2
1.1.3 Current trends 3
1.1.4 Home and small business usage 4
1.2 What is EPABX? 5
1.2.1 Business Phone System for Office Communication 6
1.2.2 Range of functions 6
1.2.3 Components of EPABX 8
1.2.3.1 Things to do before and After Fixing EPABX System 8
1.2.4 Before Fixing EPABX System 9
1.2.5 After Fixing EPABX System 9
Chapter 2 10-16
2.1 Steps to Install an EPABX System 10
2.2 Installing EPABX 10
2.2.1 Inspect the Premises 10
2.2.2 Wiring for Extension Lines 11
2.2.3 Programming the PBX Machine 11
2.3 Functions of the EPABX System 11
2.3.1 Functions of EPABX System in Office Phone Systems 12
2.4 Guidelines to Use an EPABX System 13
2.4.1 Instructions to use EPABX system 14
2.4.2 Features and Benefits of IP PBX Systems 15

6. vi
Chapter 3 17-21
3.1 Benefits of IP PBX 17
3.1.1 Cost Reduction 17
3.1.2 Choice 17
3.1.3 Flexibility 17
3.2 EPABX vs. VOIP 18
3.2.1 EPABX System 18
3.2.2 VOIP System 19
3.2.3 EPABX System vs. VOIP Services 19
3.3 Advantages of EPABX Systems 20
3.3.1 Sharing of Resources 20
3.3.2 Easy Programming 20
3.3.3 Expandable System 20
3.3.4 Occupies Compact Space 20
3.3.5 Essential Standard Features 21
3.3.6 Additional Features 21
3.4 IVR, Voice Mail, LCR 21
Chapter 4 22-59
4.1 Types of EPABX Systems 22
4.1.1 Analog PBX 22
4.1.2 Analog system pbx (Using Phone Valet with PBX and KSU Telephone
Systems) 22
4.1.3 Connecting to a Key Switch Unit (KSU) 23
4.1.4 Connecting to a PBX with digital extensions 24
4.1.5 Connecting to a PBX with analog extensions 25
4.1.6 Using phone Valet on your personal PBX extension 26
4.2 Digital PBX 26
4.2.1 Digital pbx system 26
4.2.2 Analog versus digital phone systems 27

7. vii
4.3 IP PBX 27
4.3.1 IP PBX (How an IP PBX / VOIP phone system works) 28
4.4 Hybrid PBX 28
4.4.1 Hybrid PBX architecture 29
4.5 Automatic Call Distribution (ACD) Operation 30
4.6 Analog and Digital Telephone Stations 31
4.7 Homes 3 to 9 lines 32
4.7.1 Other Features 33
4.8 T1 Line 34
4.8.1 What is a T1 Line & Why is a T1 line required? 34
4.8.2 Salient points / Advantages of T1 lines 35
4.8.3 Key systems 38
4.8.4 Electromechanical shared-control key systems 38
4.8.5 Electronic shared-control systems 39
4.8.6 Additionally, these more modern systems allowed a vast set of features
including 39
4.8.7 Independent key sets 40
4.8.8 Hybrid key phone systems 40
4.8.9 Private branch exchange 41
4.9.0 PBX functions 43
4.9.1 Interface standards 45
4.9.1.1 Interfaces for connecting extensions to a PBX include 45
4.9.1.2 Interfaces for connecting PBXs to each other include 45
4.9.1.3 Interfaces for connecting PBXs to trunk lines include 45
4.9.1.4 Interfaces for collecting data from the PBX 46
4.9.2 Hosted PBX systems 46
4.9.3 Mobile PBX 47
4.9.4 IP-PBX 48
4.9.5 Spider EPABX system 48
4.9.5.1 Operating environment 49

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4.9.5.2Cabling 49
4.9.5.3 Features 49
4.9.5.4 Specifications 50
4.9.5.5 MS48C PBX System 50
4.9.5.6 Extension Features 52
4.9.5.7 Solution 53
4.9.5.8 Specification 54
4.9.5.9 MS26 Series PBX Systems 54
4.9.6.0 IPV10 and IPV20 55
CHAPTER 5 60-61
5.1 Requirement Analysis 60
5.2 Size of the EPABX 60
5.3 PBX Features and Benefits 60
5.4 Future Upgrades and Price 60
5.5 Selecting the EPABX System Provider 61
APPENDIX A 62-74
APPENDIX B 75-92
APPENDIX C 93-109
APPENDIX D 110-111
APPENDIX E 112-113
Bibliography 114

9. ix
LIST OF FIGURE
Figure No Tittle Page No
Figure 1.1 Circuit diagram 1
Figure 1.2 Panasonic EPABX 2
Figure 1.3 General trunking diagram 3
Figure 1.4 Pbx Diagram 5
Figure 1.5 Block diagram of EPABX 6
Figure1.6 (a) EPABX Syst. (b)EPABX Syst. in Office 8
Figure 2.1 (a) Various Components involved
(b) Setting up an EPABX 10
Figure 2.2 EPABX System 11
Figure 2.3 Operational Flowchart of EPABX 12
Figure 2.4 (a) EPABX System and (b) Circuit 14
Figure 2.5 (a) Working of IP PBX and (b)Internet based PBX 15
Figure 3.1 (a) VOIP Diagram and (b) A Digital EPABX 18
Figure 3.2 Bsnl EPABX 20
Figure 4.1 EPABX types 22
Figure 4.2 Connecting phone valet alongside a KSU or
PBX with digital extension 24
Figure 4.3 Connecting phone valet alongside a KSU or
PBX with analog extension 25
Figure 4.4 Digital PBX System Picture 26

10. x
Figure 4.5 VOIP phone system works 28
Figure 4.6 Hybrid PBX 29
Figure 4.7 ACD operation 30
Figure 4.8 Small PBX System 31
Figure 4.9 Block diagram of small PBX 32
Figure 4.9.0 Home 3 to 9 lines 32
Figure 4.9.1 Architecture Diagram of T1 Line 34
Figure 4.9.2 Rotatory phone system 37
Figure 4.9.3 Nortel T Series Key System Telephone 40
Figure 4.9.4 EPABX exchange 43
Figure 4.9.5 Spider EPABX system 48
Figure 4.9.6 MS48C EPABX system 51
Figure 4.9.7 (a) KAREL IPV10 and (b) KAREL IPV20 56

11. xi
LIST OF TABLE
Table no Title Pageno
Table 1 Specification of spider EPABX system 50
Table 2 EPABX technical parameters 82
Table 3 Hardware and software requirements 89

12. xii
LIST OF ABBREVIATION
IC Integrated circuit
PCB Printed circuit board
PBX Private Branch exchange
EPABX Electronic private automatic branch exchange
PSTN Public switched telephone network
IP Internet Protocol
VOIP Voice over internet Protocol
IVR Interactive voice response
LCR Least cost routing
KSU Key switch unit
ACD Automatic call distribution
POTS Plain old telephone service
UDP User datagram protocol
CTI Computer telephony integration
ACD Automatic call distribution

13. 1
CHAPTER 1
INTRODUCTION
1.1EPABX (Electronic Private Automatic Branch Exchange)
1.1.1 History:
The term PBX was first applied when switchboard operators ran company switchboards
by hand. As automated electromechanical and then electronic switching systems
gradually began to replace the manual systems, the terms PABX (private automatic
branch exchange) and PMBX (private manual branch exchange) were used to
differentiate them. Solid state digital systems were sometimes referred to as EPABXs
(electronic private automatic branch exchange). Now, the term PBX is by far the most
widely recognized. The acronym is now applied to all types of complex, in-house
telephony switching systems, even if they are not private, branches, or exchanging
anything.
Figure 1.1circuit diagram

14. 2
PBXs are distinguished from smaller "key systems" by the fact that external lines are not
normally indicated or selectable at an individual extension. From a user's point of view,
calls on a key system are made by selecting a specific outgoing line and dialing the
external number. A PBX, in contrast, has a dial plan. Users dial an escape code (usually a
single digit; often the same as the first digit of the local emergency telephone number)
that connects them to an outside line (DDCO or Direct Dial Central Office in Bell System
jargon), followed by the external number. Some modern number analysis systems allow
users to dial internal and external numbers without escape codes by use of a dial plan
which specifies how calls to numbers beginning with certain prefixes should be routed.
Figure 1.2 Panasonic EPABX
1.1.2 System components:
A PBX often includes:
 The PBX’s internal switching network.
 Microcontroller or microcomputer for arbitrary data processing, control and logic.
 Logic cards, switching and control cards, power cards and related devices that
facilitate PBX operation.
 Stations or telephone sets, sometimes called lines.
 Outside Telco trunks that deliver signals to (and carry them from) the PBX.
 Console or switchboard allows the operator to control incoming calls.

15. 3
 Uninterruptible power supply (UPS) consisting of sensors, power switches
and batteries.
 Interconnecting wiring.
 Cabinets, closets, vaults and other housings.
Figure 1.3 general trunking diagram
1.1.3 Current trends:
One of the latest trends in PBX development is the VoIP PBX, also known as an IP-
PBX or IPBX, which uses the Internet Protocol to carry calls. Most modern PBXs
support VoIP. ISDN PBX systems also replaced some traditional PBXs in the 1990s, as
ISDN offers features such as conference calling, call forwarding, and programmable
caller ID. However, recent open source projects combined with cheap modern hardware
are sharply reducing the cost of PBX ownership.
For some users, the private branch exchange has gone full circle as a term. Originally
having started as an organization's manual switchboard or attendant console operated by

16. 4
a telephone operator or just simply the operator, they have evolved into VoIPcenters that
are hosted by the operators or even hardware manufacturers. These modern
IP Centrex systems offer essentially the same service, but they have moved so far from
the original concept of the PBX that the term hardly applies at all.
Even though VoIP gets a great deal of press, the old circuit switched network is alive and
well, and the already bought PBX's are very competitive in services with modern IP
Centrex’s. Currently, there are four distinct scenarios in use:
 PBX (Private and Circuit Switched)
 Hosted/Virtual PBX (Hosted and Circuit Switched) or traditional Centrex
 IP PBX (Private and Packet Switched)
 IP Centrex or Hosted/Virtual IP (Hosted and Packet Switched)
Since in reality people want to call from the IP side to the circuit
switched PSTN (SS7/ISUP), the hosted solutions usually have to maneuver in both
realms in one way or another. The distinctions are seldom visible to the end user.
1.1.4 Home and small business usage:
Historically, the expense of full-fledged PBX systems has put them out of reach of small
businesses and individuals. However, since the 1990s many small, consumer-grade and
consumer-size PBXs have become available. These systems are not comparable in size,
robustness or flexibility to commercial-grade PBXs, but still provide many features.
The first consumer PBX systems used analog (POTS) telephone lines, typically
supporting four private analog and one public analog line. They are the size of a
small cigar box. In Europe these systems for analog phones were followed by consumer-
grade PBXs for ISDN. Using small PBXs for ISDN is a logical step, since the
ISDN basic rate interface provides two logical phone lines (via two ISDN B channels)
which can be used in parallel. Small, entry-level systems are also extremely cheap .With
the adoption of VoIP by consumers, consumer VoIP/pbxhave appeared, with PBX
functions becoming simple additional software features of consumer-grade routers and
switches.

17. 5
Open source projects have provided PBX-style features since the 1990s. These projects
provide extreme flexibility and features, including the means to inspect and change the
inner working of a PBX. Lowered entry barriers for new manufacturers created business
opportunities for newcomers.
1.2 What is EPABX:
Figure 1.4 Pbx Diagram
Epabx
EPABX is an abbreviation that stands for Electronic Private Automatic Branch
Exchange. It comes under the category of business phone systems which serve a business
environment. Multi-line connections can be made through a single telephonic connection.
It is an office equipment of immense use for telephonic connectivity with extensions of a
single phone line. It can be rented from office equipment suppliers too.

18. 6
1.2.1 Business Phone System for Office Communication:
EPABX has proven to be of immense use in communicating within office, making
routine work simpler. It can be defined as a switching system for calls that enables both
internal as well as external switching functions in an organization. Typically up to 10,000
subscribers can be accommodated by a single EPABX system.
Figure 1.5 block diagram of EPABX
1.2.2 Range of functions:
EPABX as a business phone system possesses a versatile range of functions. The
numerous tasks that can be performed by EPABX are listed below.

19. 7
 Auto Attendant
 Automatic call distributor
 Automated directory services (where callers can be routed to a given employee by
keying or speaking the letters of the employee's name)
 Automatic ring back
 Call accounting
 Call forwarding on absence
 Call forwarding on busy
 Call park
 Call pick-up
 Call transfer
 Call waiting
 Conference call
 Custom greetings
 Customized Abbreviated dialing (Speed Dialing)
 Direct Inward Dialing
 Direct Inward System Access (DISA) (the ability to access internal features from
an outside telephone line)
 Do Not Disturb (DND)
 Follow-me
 Music on hold
 Night service
 Shared message boxes (where a department can have a shared voicemail box)
 Voice mail

20. 8
1.2.3 Components of EPABX:
 Internal switching network.
 Microcontrollers and microcomputer for arbitrary data processing for control and
the logic.
 Logic cards, switching and control cards, power cards and related devices to
facilitate operation.
 Stations or telephone sets, sometimes called lines.
 External Telco trunks that deliver signals to and from the EPABX.
 Console or switchboard allows the operator to control incoming calls.
 UPS, connecting wiring, cabinets and other housing materials.
The selection of an EPABX must be carefully done based on a detailed study of
the traffic flow and needs of the office. They make communication within office easier
and hence become a requisite as a business phone system in an office environment.
1.2.3.1 Things to do before and After Fixing EPABX System:
(a) (b)
Figure1.6 (a)EPABX System and (b)EPABX System in Office Space
Configuring an EPABX system involves many steps. You have to first check for the
basic requirements, decide on your need, and then proceed with configuration. The
number of extension lines will differ based on the requirements.

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1.2.4 Before Fixing EPABX System:
 The area should be well protected from rain.
 It should be an air conditioned area.
 Power back, power connections and earthing issues must be checked and verified.
 Dust free room is necessary.
 Connection diagram mentioning the places to fix EPABX machines and computer
for programming.
 Wiring must be planned having the future enhancements in mind.
1.2.5 After Fixing EPABX System:
 The number plan and the list of extension lines should be documented and stored
safely.
 Every extension should be numbered based on MDF (Main Distribution
Frame) and stored for future reference.
 According to the saved document the extension phones should be configured. The
configuration should be done based on the guidance of the service providers or by
referring the user manual.
 After configuring the extension lines, each line should be checked and verified.
 A back up of the program file will help you for future reference.
Future enhancements of EPABX systems can be done on your own referring to the user
manual. It is always better to avail EPABX service providers for safe configuration.

22. 10
CHAPTER 2
INSTALLATION OF EPABX
In this chapter we will describe how to install the EPABX in real life scenarios.
2.1 Steps To Install an EPABX System:
(a) (b)
Figure 2.1 (a)Various Components involved and (b) Setting up an EPABX
An EPABX system can be defined as a private telephone exchange which is of specific
use to a business or organization. It is a cost effective way of providing communication
among the employees in an organizational set up. Different organizations have diverse
needs and so different types of EPABX systems are available in the market.
Any EPABX system must be installed by technicians only. However, a run through of the
following points will help you prepare for the installation of this system in your office.
2.2 Installing EPABX:
2.2.1 Inspect the Premises:
Before installing, inspect the location where the EPABX is intended to be installed.
Select an area that is well protected from

23. 11
Rain and other natural deterrents. An air conditioned area with power back up, power
connection, and ear thing can be checked and selected.
It is suggested that a wiring diagram be made of the intended connection with all the
modules like PBX machine, computer for programming and monitoring, battery
connection etc. clearly mentioned.
2.2.2 Wiring for Extension Lines:
Once the connection layout and wiring diagram is finalized, wiring for the extension lines
needs to be done. Future enhancements and redundancy must be kept in mind and proper
arrangements for the same should be made. Always opt for sealed wiring, as open wiring
can increases the chances of cable cutting and disconnection.
2.2.3 Programming the PBX Machine:
After the wiring is done, the EPABX machine needs to be configured. All required
features like number plan, list of extension lines, etc. need to be properly wired and
documented. Extension numbers needs to be stored on the MDF (Main Distribution
Frame) for future reference. After the numbering and tagging, the machines need to be
sealed properly so that unauthorized persons are not able to make any changes.
In a big organization with a complex PBX system, the details are very minute and the
wiring can get quite complex. It also needs more planning and documentation as well.
Ensure you call only licensed technicians for setting up the EPABX system in your
office.
2.3 Functions of the EPABX System:
Figure 2.2 EPABX System

24. 12
When you plan to run a business where the basic need is phone systems, you need to plan
smart. Customer service industries will never miss out the opportunity of using EPABX
system for their office phone system. You can no way relax the need of EPABX system
as a part of customer service. Contacting the best EPABX dealer or office equipment
dealer, will help you making a right choice.
Figure 2.3 Operational Flowchart of EPABX
2.3.1 Functions of EPABX System in Office Phone Systems:
 Need not miss your phone calls henceforth, when you are not available in your
seat. Your office phone system that is connected with EPABX system has auto
attendant option. You need to do some basic setting to auto receive your call.
 Option of auto dialer in EPABX system will help you calling your customers
automatically when the numbers are fed into it. When you record the message that
has to be delivered to the dialed number, your job becomes easier. You can
program it to dial as many numbers you want.

25. 13
 When you have more than 4 or 5 phone lines connected in your office, EPABX
system has an exclusive option of automatic call distributor. When there is call
traffic, it distributes the call equally to number of office phone systems available.
 Your office phone systems connected to EPABX system will help you in call
accounting, blocking and forwarding. Just programing your phone system will
save your man power and time consumption.
 The EPABX system connected to your office phone system enables you to have
conference call. You can have a voice or video conference call using the EPABX
system.
 Accessing voice mail with the help of EPABX system will help you send or
receive voice mail at any point in time.
 You can call both outside numbers an internal extension using the same EPABX
system. Normal office phone systems do not such options.
 EPABX system connected to your office phone system has the best battery
backup. You can either connect them to a power source or use it in battery.
 In built alarm system in your EPABX system is an added advantage. You can fix
alarm for public meeting or important appointments.
 You can also feed them to send bulk public voice messages to reach out your
people easily. When used right EPABX system is a boon to voice industry.
Check if all the above said functions are available with the EPABX system you book for
your office phone system.
2.4 Guidelines to Use an EPABX System:
Waiting long time for a person to come on the dialed office communication number is
definitely disgusting! Fixing an EPABX system in office communication telephone helps
you contacting the person on time. The best office equipment suppliers will serve you
better.
Unlike the plain ordinary telephones EPABX system offers you many options. Once your

26. 14
(a) (b)
Figure 2.4 (a)EPABX System and (b) Circuit
Extension is setup you can use your phone to forward calls, send voice mails to a mail id,
and you can call another extension number.
2.4.1 Instructions to use EPABX system:
 Use your telephone system connected with EPABX system to dial another
extension. Internal office communication will have four digits to reach the
other extension. Just pick your receiver dial four digit number of other
extension to make your office communication process easier.
 You can also dial outside number by pressing 0 or 1 from your office
communication telephone system. EPABX system will get you the dial
tone when you dial 0 or 1 depending upon the configuration by the
technician.
 Pick your telephone system receiver, press the voice mail button, and dial
your security code to access your voice mail. You can save or delete the
messages you receive using EPABX system in your office
communication.
 When you are away from your office communication telephone system,
you can dial 10 digit phone numbers and press the asterisk key and then

27. 15
press your security code. With this arrangement in your telephone system,
the other attenders will be able to reach your voice mail in your absence.
 You can transfer your office communication calls to another extension
number by pressing “trans” key in your EPABX system. Just dial the other
extension number after pressing “trans” key.
 There are two types of telephone system transferring.
 Blind transfer – you need not wait for the other person to pick the call,
you just transfer the call.
 Supervised transferring – after transferring your telephone system, you
will wait till the other person picks the call and introduce both ends.
 You can place your office communication telephone system calls on hold
by pressing the “hold” button in EPABX system. This will put the caller
on hold for specific time period and remind you by ringing again. Based
on the EPABX system you have, your telephone system will also alert you
with blinking lights.
 You can logon to your administrator web page or refer the user manual for
other usage related instructions. Go ahead make your way of office
communication easier. Telephone systems connected with EPABX
systems are a boon for all industries.
2.4.2 Features and Benefits of IP PBX Systems:
(a) (b)
Figure 2.5(a) Working of IP PBX and (b)Internet based PBX

28. 16
An IP PBX (Internet protocol- private branch exchange) is a business telephone system designed
for communication over the IP data networks. All conversations are sent as data packets over the
Internet. The technology includes advanced features of scalability and robustness which is
important in a growing corporate set up.
IP PBX has an optional gateway with which it can incorporate the traditional telephone
lines to this advanced voice and data network. This ensures that the corporate offices do
not need to change their existing telephone number while opting for IP PBX system.

29. 17
CHAPTER 3
UTILITIES OF EPABX
In this chapter we provide a brief description about the how important the EPABX in real
life and its advance versions, which breaks the communication barriers among inter-
organization departments in industry scenarios as well as in college campus too.
3.1 Benefits of IP PBX:
3.1.1 Cost Reduction:
There is no need to buy extra expansion boards or expensive add-ons while shifting to IP
PBX system. The PBX can easily scale and so it’s easier to add more lines or increase
servercapacity.
You also can opt for different vendors thereby eliminating the need to buy exclusively
from a single vendor and reducing costs on moves and changes to the PBX system.
3.1.2 Choice:
You have various options to choose from the internet server to the vendors. You can
choose which PC, server, embedded device or system to use your IP PBX. You can
choose the operating system, operators and also a variety of phones from different
manufacturers.
3.1.3 Flexibility:
A lot of flexible options are available with the IP PBX Phones-
 Expand the network when there is a need. Even when you move premises or
expand to different premises, they can be easily shifted without a change in the
number.
 You can also opt for the feature that the PBX calls your mobile phone as well as
the office phone so that you never miss important businesses call.
 You can hold conference calls, queue calls to support the customer care
team, record calls or switch call routing according to the time of the day.

30. 18
 You will be able to connect employees who work from home to the office
network. This also helps employees connect to the IP phone while travelling.
IP based phones have revolutionized the way a corporate office works. It has great
benefits like lower prices, greater features and a wide variety of choices which makes it
an ideal system in any office.
3.2 EPABX vs. VOIP:
(a) (b)
Figure 3.1 (a) VOIP Diagram and (b) A Digital EPABX
Communication is an important aspect in any business. So as to be able to run the
business efficiently and effectively, active communication between the employees and
between the company and the customer is essential. Telecommunication has a very
important role to play in this regard. Advancement of technology has enabled effective
and cost efficient communication methods.
The EPABX (Electronic Private Automatic Branch Exchange) system and the VOIP
(Voice over Internet protocol) have revolutionized inter-office and intra-office
communication. However, there are some pros and cons to both the systems and the
feasibility of the system will vary from organization to organization.
3.2.1 EPABX System:
An EPABX system refers to the private branch exchange service use for communication
in offices. It is a telephone system where in the incoming phone calls are received at a

31. 19
main point and then routed to various extensions of departments and employees. There
are actual physical lines that are used along with a main control panel.
3.2.2 VOIP System:
VOIP systems use Voice over the Internet protocol for communicating. The voice is
transmitted over the internet. This system turns voices into digital data to send it through
the Internet. A wireless access to the Internet and a computer is all the hardware required
and so the VOIP system has greater flexibility.
3.2.3 EPABX System vs. VOIP Services:
The EPABX system is ideal for big offices which need the features of voice mail, auto
attendants ring groups, etc. for the smooth running of business. It also has the advantage
of providing control over the telephone system. You can adjust, create users, and delete
users; dedicated extensions are also possible for safe and error free communication.
However, the need for a dedicated person to manage the EPABX is one of the main
disadvantages. Also, it has higher cost of installation, upgrading is difficult and costly as
the other major drawbacks.
A VOIP system is preferred for small businesses and homes based businesses as the cost
is less. Businesses on tight budgets benefit the most from VOIP technology. It is
also easy to set up as there is not much hardware or wiring involved. There are also many
other features like easy up-gradation and hassle free transfer of premises. However,
the drawbacks are that the voice clarity and security will depend on the Internet
connection. Also, in case of loss of internet connectivity, phone calls will also be not
possible.
Both the EPABX system and VOIP system has its advantages and disadvantages. A
careful analysis of the features and their feasibility to your organization must be
considered before opting for either system.

32. 20
3.3 Advantages of EPABX Systems:
Figure 3.2bsnl EPABX
EPABX system is an impressive business solution to meet the office needs of internal
communication. It provides a business phone system that enables switching internal calls
between two or more persons on different extensions on the same business phone
connection. EPABX system solutions are provided by office equipment suppliers who
shall enable the service in an organizational set up.
3.3.1 Sharing of Resources:
Within an office set up, the employees can share phone lines. Several extensions may be
connected to a single phone line, thus reducing the overall phone expenses. In case of
external calls, they may be routed from a single incoming mode and directed to the
respective extension number from there.
3.3.2 Easy Programming:
The EPABX system is totally programmable. It facilitates complex installation
procedures and other integrated requirements for communication.
3.3.3 Expandable System:
With the growth of the company and the communication needs, the basic network of
business phone system can also be expanded easily without much hassle.
3.3.4 Occupies Compact Space:
The physical hub of an EPABX system is low profile and does not require large space to
be accommodated. Hence space constraints are not an issue.

33. 21
3.3.5 Essential Standard Features:
It offers several basic call features needed for office communication. Few of them are
given below.
 Auto Attendant
 Automatic ring back
 Call transfer
 Call waiting
 Conference call
3.3.6 Additional Features:
These days, many fancy features are also being offered by the EPABX systems which
help in everyday office affairs.
 Alarms
 Remainders for meeting, appointments, etc.
 Music on hold
 Night service
 Do Not Disturb (DND)
3.4IVR, Voice Mail, LCR:
Supportive features like Interactive Voice response (IVR), Least Cost Routing and Voice
mail services not only increase the efficiency and productivity; but also lower the
expenses incurred in the office.
Owing to many such facilities, EPABX has become a requirement for intra-office
communication between departments or otherwise.

34. 22
CHAPTER 4
CLASSIFICATION OF EBAPX
4.1 Types of EPABX Systems:
Figure 4.1 EPABX types
EPABX enables easier communication in an organization. It is very useful office
equipment through which multiple line extensions can be given from a single telephonic
line. Different phone users can be managed from a single business phone line. The
services of office equipment suppliers can be availed to make use of EPABX systems.
EPABX stands for Electronic Private Automatic Branch Exchange. There are 4 different
types of EPABX systems based on the technology involved.
4.1.1 Analog PBX:
 Uses “phone–box” system through which many phones are connected through
phone lines.
 Requires a person to operate the switchboard controlling the calls.
 Companies providing service – Nortel, Toshiba, Panasonic.
4.1.2 Analog system pbx(Using Phone Valet with PBX and KSU Telephone
Systems):
This is a guide to help you use Phone Valet with PBX and KSU telephone systems.

35. 23
 Connecting to a Key Switch Unit (KSU)
 Connecting to a PBX with digital extensions
 Connecting to a PBX with analog extensions
 Using Phone Valet on your personal PBX extension
4.1.3 Connecting to a Key Switch Unit (KSU):
Key Switch Units are phone systems that use standard phone wiring and often standard
analog phone lines but offer extensions and paging features. Key Switch Units do not
manage the outside phone lines for you - they require the users to select the desired phone
lines when answering and placing calls. This can be used to Phone Valet’s advantage.
Phone Valet can be used to provide dialing, auto-attendant, voice mail and call recording
features. To connect Phone Valet, do not connect it to the KSU unit. Instead, split the
outside lines and connect the Parliant Telephony Adapters there. You will need one
Phone Valet Message Center package for each outside line.
Automatic Attendant:
Phone Valet can act as a full auto attendant using the Page and Pause mailbox types. It
cannot send a call to a specific phone, but it can announce the caller's choice over the
computer and networked computers with the Phone Valet Anywhere add on. To do this,
simply create a call tree with a menu of choices for your caller, and make the choices
Page and Pause. Phone Valet will then alert your Phone Valet clients of incoming calls
and which line they should answer. If no one answers after a set amount of time, send the
caller to voice mailboxes that you also create in your tree.
Dialing: Full dialing should work with most KSU systems. Simply dial, and pick up on
any line. Phone Valet will then dial when you pick up on the line. Note, your KSU must
pick up on the line for Phone Valet to recognize it. KSU systems that wait for the phone
to start dialing before picking up will not work.
Voice Mail: Simply set Phone Valet to answer after the desired number of rings. Phone
Valet will answer the call if no one answers.

36. 24
Call Recording: Phone Valet can record all calls coming in or placed on the outside
phone lines. Phone Valetcannot record calls from one internal extension to another.
4.1.4 Connecting to a PBX with digital extensions:
Phone Valet cannot communicate directly to PBX systems. But you can split the outside
line and connect the Parliant Telephony Adapters there. You will need one Phone Valet
Message Center package for each outside line. See the diagram below:
Figure 4.2 connecting phone valet alongside a KSU or PBX with digital extension
Automatic Attendant: Phone Valetcannot act as an auto attendant. Most PBX systems
do not allow you to pick up on a specific outside line.
Dialing: Phone Valet’s dialing features cannot be used with a digital PBX. Most PBX
systems do not allow you to pick up on a specific outside line.
Voice Mail: Set Phone Valet to answer after the desired number of rings. Phone Valet
will then pick up if no extension (or auto-attendant) on the PBX system picks up on the
line.
Call Recording: Phone Valet can automatically record all calls on the outgoing line.
Manually recording calls to outside lines is possible, but may be cumbersome when
trying to determine which call is originating from your extension vs. another. Phone
Valet cannot record calls from one extension to another.

37. 25
4.1.5 Connecting to a PBX with analog extensions:
If your PBX system can provide analog extensions, you can connect phone Valet to an
analog extension. To handle more calls simultaneously, you can create additional
extensions for additional Parliant Telephony Adapters. You will need one phone Valet
Message Center package for each simultaneous call you wish to be able to answer. See
the diagram below:
Figure 4.3 connecting phone valet alongside a KSU or PBX with analog extension
Automatic Attendant: If your PBX switch supports blind transfer (flash the line, dial the
number, and hang up) then phone Valet can be used as an auto attendant. Configure your
PBX to send all incoming calls to an extension that phone Valet is connected to. Then
have phone Valet answer with a menu of your choosing. In the menu, enter Transfer
choices for each extension.
Voice Mail: Configure unanswered calls on all other extensions to transfer to the
extension connected to phone Valet. phone Valet can then offer voice mail choices for
the caller. Note, it is not possible to determine which extension the caller chose
previously, so you cannot automatically send the caller to the voice mailbox of the person
the caller was attempting to reach. Keep this in mind if using phone Valet as an auto
attendant, and voice mail. The caller will enter the extension for someone, and if

38. 26
unanswered, will be sent back to the same menu. For this reason, it is not advisable to use
the same phone Valet for voicemail and auto attendant in this configuration.
Call Recording: phone Valet cannot be used to record live calls in this configuration.
Dialing: phone Valet cannot be used to automatically dial calls in this configuration.
4.1.6 Using phone Valet on your personal PBX extension:
If your PBX system provides you with an analog extension, simply connect phone Valet
as you would in a home or office with a single phone line. All of Phone Valet’s features
are available on your extension alone.
4.2 Digital PBX:
 Sound converted to digital signal and sent on a channel through circuit switching.
 It is the way contemporary phone companies adopt to connect to callers.
 Companies providing service – Uni phone Telecommunications, Rexon
Technology and Panasonic.
4.2.1 Digital pbx system:
Effective communication іn business іѕ crucial tο having ехсеƖƖеnt relationships wіth
customers, associates аnԁ partners. A well-organized аnԁ intelligently used phone system
саnhеƖр a business serve іtѕ customers more efficiently, аnԁ share thοuɡhtѕаnԁ
information wіth associates аnԁ partners effectively.
Figure 4.4 Digital PBX System Picture

39. 27
4.2.2 Analog versus digital phone systems:
 Analog phones transfer sound through continuous waves. Thеѕе signals аrе easily
disturbed bу external interference such аѕ noise аnԁ weather conditions, whісh іѕ
whу sound іѕ sometimes fuzzy іn analog phones. Digital phones digitize thе
signal іntο binary units thаt аrе recombined аt thе οthеr еnԁ. Thіѕ mаkеѕthе
quality οf sound much better іn digital systems.
 Digital phone systems аrе more easily customized thаn analog phones.
Customization οf software іѕ simpler аnԁ cheaper thаn hardware. Digital phones
саnbе reprogrammed easily whereas analog telephone systems саnbе
reprogrammed οnƖуbуthе manufacturer οrаn expert іn analog phone technology.
 Digital phones аrе costlier thаn analog phone systems. Thе initial setup,
programming аnԁ maintenance οfthе digital system саnοnƖуbе done bу trained
technicians.
4.3 IP PBX:
 Phones are equipped with a network interface card and integrated into a network
of phones.
 These are newer and less used than some of the older PBX systems.
 They are easily maintained, allow for applications to be added to them, and
manage multiple simultaneous calls on a single network. As Voice over IP
technology becomes more popular, these easy-to-maintain systems are being
used more.
 A variant of IP PBX, called SIP PBX, exists which is used for multimedia
communications on the same network.
 Service provider companies - 3Com, Inter-Tel and Cisco.

40. 28
4.3.1 IP PBX (How an IP PBX / VOIP phone system works):
A VOIP Phone System / IP PBX system consists of one or more SIP phones / VOIP
phones, an IP PBX server and optionally includes a VOIP Gateway. The IP PBX server is
similar to a proxy server: SIP clients, being either soft phones or hardware based phones,
register with the IP PBX server, and when they wish to make a call they ask the IP PBX
to establish the connection. The IP PBX has a directory of all phones/users and their
corresponding SIP address and thus is able to connect an internal call or route an external
call via either a VOIP gateway or a VOIP service provider.
Figure 4.5 VOIP phone system works
4.4 Hybrid PBX:
 It is a digital PBX with IP PBX capabilities.
 Popular, as it allows users to have the best of both worlds.
 Older phones without a network chip can still be used, but they can also be
upgraded to include network chips if the funds for an upgrade become available.
 Service provider companies - Toshiba, Inter-Tel, and Mitel.

41. 29
 The choice of the EPABX type has to be based on office needs and price
affordability.
Figure 4.6 hybrid PBX
4.4.1 Hybrid PBX architecture:
Now what happened to the TDM PBX systems once Voice-over-IP technology could not be
ignored anymore by the PBX vendors? PBX vendors designed a new board. Not just one but
depending on the manufacturer a couple of boards that provided H.323 registrar or SIP proxy
functionalities and had an Ethernet plug in order to allow IP phones to connect to the PBX (well
now it’s a “hybrid” PBX as it provides IP and TDM extensions). But not just extensions became
connected via IP to the cabinets but also entire cabinets could be placed in a distributed fashion,
connecting with the main system via IP. Proprietary protocols tunneled in H.323 or SIP packets
(in order to claim to be standard compliant) provided the same feature set to users as they were
used with their previous phone. The good thing was that savings for the company by just using

42. 30
one common data/voice cabling system could be realized, no user trainings needed to be
performed as the user experience basically was that they have a new looking phone now plugged
into a different wall socket. I don’t want to sound sarcastic here: There was definitely the
advantage for administrators as well as users to become familiar with VoIP technology and to
figure out the right migration path for companies to move to VoIP. At the same time VoIP
technology in General had the chance to mature. For hybrid PBX systems as an examplethe
following Figure shows a simplified view of a hybrid PBX:
4.5 Automatic Call Distribution (ACD) Operation:
This figure shows a sample automatic call distribution (ACD) system that uses an
interactive voice response (IVR) system to determine call routing. When an incoming is
initially received, the ACD system coordinates with the IVR system to determine the
customer's selection. The ACD system then looks into the databases to retrieve the
customers' account or other relevant information and transfer the call through the PBX to
a qualified customer service representative (CSR). This diagram also shows that the ACD
system may also transfer customer or related product information to the CSR.
Figure 4.7 ACD operation

43. 31
4.6 Analog and Digital Telephone Stations:
This diagram shows the difference between standard analog telephone stations and more
advanced PBX stations. This diagram shows that analog telephones receive their power
directly from the telephone line and digital PBX telephones require a control section that
gets its power from the PBX system. Analog telephones also use in-band signaling to
sense commands (e.g., ring signals) and to send commands (e.g., send dialed digits).
Digital telephones use out-of-band signaling on separate communication lines to transfer
their control information (e.g., calling number identification).
Figure 4.8 Small PBX System
This diagram shows a block diagram of a small PBX system. This diagram shows that a
PBX system contains line interface cards that connect the PBX to outside communication
lines (such as the PSTN). The PBX also contains station interface cards that adapt the
PBX signals to the type of PBX extensions (PBX telephones) that are used with the
system. The PBX unit contains a switch to interconnect stations to other stations or to
outside lines. PBX call control software coordinates the overall operation of the PBX
system. The PBX unit in this example has a data interface connection to allow a control
terminal to setup and configure the settings of the PBX system. The PBX also has
optional voice mail that connects some of the station interface lines to a voice mail
storage system (e.g. a computer hard disk) that allows users to connect to the voice mail

44. 32
and play, transfer and delete stored audio messages. This example also shows that PBX
systems may have backup power supplies to allow the PBX telephone system to continue
to operate even when the primary power source is lost.
Figure 4.9 block diagram of small PBX
4.7 Homes 3 to 9 lines:
Highly versatile and flexible EPABX system to
increase efficiency and add comfort at your
home.
An ideal communication system for small home
and offices.
Figure 4.9.0 home 3 to 9 lines

45. 33
FEATURES:
 Full Caller ID PBX
 Internal CLI at all extns. In Round Robin / Simultaneous / Staircase Ring Modes
 Memory Dialing : (80 memories)
 Eight Levels of Restricted Dialing
 Three Party Conference
 Programmable "Flash" Durations
 Ring Once Mode
 Group Call / Emergency Reporting
 Centrex Line Compatible : Behind PBX Operation
 Day / Night Mode
 Discriminate Ringing
 Remote Servicing
 Power Failure Transfer
4.7.1 Other Features:
 Single Digit Numbering
 Extn. To Extn. Call
 External Call
 Auto Call Back on Busy Extn/Trunk
 Last No. Redial
 Intercept With or Without Tone
 Call Parking
 Parked Call Pick-up
 Call Pick-up from Ringing Extn
 Call Camp On
 Camped Call Pick-up
 Call Transfer
 Call Forwarding
 Door Phone Call

46. 34
 Door Lock Open
 Group call / Emergency Call
 Incoming Ring Options- Round Robin , Stair Case & Simultaneous Ring
4.8 T1 Line:
Figure 4.9.1Architecture Diagram of T1 Line
4.8.1 What is a T1 Line & Why is a T1 line required?
You should be familiar with trunk lines – The single land-line phone connection provided
by your telecom provider at both residential as well as commercial (office) locations. So,
you can use these trunk lines to make outgoing calls – Local Call, Outstation Calls, etc.
But you can make only one call at a time. So, if two or more users want to call different
people, it may not be possible with a single analog trunk line.
If you have an office, you should be having a small EPABX too. You can apply for
multiple analog trunk lines and share it with all the users. Having 2/3 analog trunk lines
for a small office is ok, but if you have an office with more than 50/100 people it
becomes cumbersome to apply for more individual analog trunk lines. Terminating each

47. 35
trunk line requires a separate trunk port in your EPABX & you get separate bills for each
line, every month. With more lines, the process just becomes too cumbersome.
That’s when you should look at T1 lines – A T1 line has 24 Digital Voice Channels
(trunk lines) that are transmitted using a single circuit. Yes, a single circuit can carry up
to 24 calls simultaneously! They use multiplexers (at the public telephone exchange
office end) and de-multiplexers (at the customer premises – private EPABX) to achieve
this. A T1 line occupies just one T1 port in the PBX but still 24 people can
simultaneously make/receive calls through the T1 line terminated on the PBX.
T1 lines are popular in the United States/ Japan / Korea. E1/PRI Lines are popular in
Europe/Asia. E1/ PRI lines are quite similar to T1 lines but instead of the 24 channels,
they carry 30 channels in a single line.
4.8.2 Salient points / Advantages of T1 lines:
 T1 lines can be terminated on an EPABX using a T1 card which is either
in-built or supplied additionally by the EPABX manufacturer.
 If you have an open source PBX, you can add a T1 card to the PCI slot of
the server (hosting the soft-pbx) and terminate the T1 line on the T1 card.
 You can terminate multiple T1 lines (using multiple T1 ports) in the same
PBX if the PBX has enough empty T1 ports, and can support so many T1
lines.
 It is possible to carry both voice and data using a T1 line. The total data
capacity of a T1 line is 1.544 Mbps when no voice calls are made using it.
You might need a data modem to terminate the T1 line and to connect to
the Internet using a T1 line.
 The data capacity of 1.544 Mbps mentioned above is bi-directional. That
means, you get 1.544 Mbps for upload as well as the same capacity for
download. Generally, only leased lines provide such a facility (not
available with broadband). This could be useful for applications like video

48. 36
conferencing, hosting a web-server etc, where a solid uplink connection is
a must.
 Some telecom service providers provide fixed capacity T1 lines for voice
and data while some of them provide dynamic capacity T1 lines that can
automatically provision the maximum data bandwidth after deducting the
bandwidth consumed by active voice calls.
 For T1 lines, there is a single fixed rental per month (with a certain
number of free calls), based on the plan you select. You get a single bill
for all the calls made through a T1 line.
 T1 lines can be provided either using copper circuits or using optical
circuits, depending on your location and the service provider. There is not
much of a difference in capacity between the two though.
 There is something called as “Fractional T1 lines” provided by some
telecom service providers that allow you to buy a limited capacity T1 line.
So, instead of 24 channels, you can get 12 channels and pay the rental/call
charges accordingly.
 T1 lines are very useful if you want to have a DID (Direct Inward Dialing)
facility in your office. Generally, telephone companies block a series of
land-line numbers and give them to you along with a T1 line (or this needs
to be purchased separately). So, instead of someone having to dial through
the PBX and typing the extension number every time to reach you, they
can just reach you by dialing your own dedicated number from anywhere.
 T1 lines can be useful at places where you are not able to get an Internet
Leased Line / Broadband connection.
 T1 line can also act as a back-up to your normal data line for Internet
connectivity.

49. 37
T1 lines are digital lines and are different from the VOIP / IP Trunks that you can
purchase from ITSP’s. But you can use the data capacity offered by the T1 lines to make
VOIP calls.
A business telephone system is any of a range of a multiline telephone systems typically
used in business environments, encompassing systems ranging from small key systems to
large scale private branch. A business telephone system differs from simply using a
telephone with multiple lines in that the lines used are accessible from multiple
telephones or “stations in the system, and that such a system often provides additional
features related to call handling. Business telephone systems are often broadly classified
into "key systems", "hybrid systems", and "private branch exchanges".
A key system was originally distinguished from a private branch exchange (PBX) in that
it allowed the station user to see and control the calls directly, manually, using lighted
line buttons, while a private branch exchange operated in a manner similar to the public
telephone system, in that the calls were routed to the correct destination by being dialed
directly. Technologically, private branch exchanges share lineage with central office
telephone systems, and in larger or more complex systems, may rival a central office in
capacity and features.
Figure 4.9.2rotatory phone system

50. 38
4.8.3 Key systems:
Key was a manually operated switch, such as the line-buttons on the phones associated
with such systems.
Key systems are primarily defined by their individual line selection buttons for each
connected phone line, a feature shared with hybrid systems. New installations of true
"key" systems have become less common, as hybrid systems and private branch
exchanges of comparable size now have similar costs and greater functionality.
Key systems can be built using three principal architectures: electromechanical shared-
control, electronic shared-control, or independent key sets.
4.8.4 Electromechanical shared-control key systems:
A typical rotary dial key telephone: The Western Electric eighteen buttons Call Director,
manufactured from 1958 to the early 80s.
Before the advent of large-scale integrated circuits, key systems were typically composed
of electromechanical components (relays) as were larger telephone switching systems.
The systems marketed in North America as the 1A, 6A, 1A1 and the 1A2 Key
System were typical and sold for many decades. 1A equipment was primitive and
required at least two KTUs per line; one for line termination and one for station
(telephone instrument) termination. The telephone instrument commonly used by 1A

51. 39
systems was the WECo 300-series telephone. In the 1960s, 1A1 key systems simplified
wiring with a single KTU for both line and station termination, and increased the features
available. As the 1A1 systems became commonplace, requirements for intercom features
increased. The original intercom KTUs, WECo Model 207, were wired for a single talk
link, that is, a single conversation on the intercom at a time. The WECo 6A dial intercom
system provided two talk links and was often installed as the dial intercom in a 1A1 or
1A2 key system. Unfortunately, the 6A systems were complex, troublesome and
expensive, and never became popular. The advent of 1A2 technology in the 1970s
simplified key system set up and maintenance. These continued to be used throughout the
1980s, when the arrival of electronic key systems with their easier installation and greater
features signaled the end of electromechanical key systems.
Two obscure key systems were used at airports for air traffic control communications, the
102 and 302 key systems. These were uniquely designed for communications between
the air traffic control tower and radar approach control (RAPCON) or ground control
approach (GCA), and included radio line connections.
4.8.5 Electronic shared-control systems:
With the advent of LSI ICs, the same architecture could be implemented much less
expensively than was possible using relays. In addition, it was possible to eliminate the
many-wire cabling and replace it with much simpler cable similar to (or even identical to)
that used by non-key systems. Electronic shared-control systems led quickly to the
modern hybrid telephone system, as the features of PBX and key system quickly merged.
One of the most recognized such system is the AT&T Merlin.
4.8.6 Additionally, these more modern systems allowed a vast set of
features including:
 Answering machine functions
 Remote supervision of the entire system
 Automatic call accounting
 Speed dialing
 Caller ID

52. 40
 Station-specific limitations (such as no long distance access or no paging)
 Selection of signaling sounds
Features could be added or modified simply using software, allowing easy customization
of these systems. The stations were easier to maintain than the previous
electromechanical key systems, as they used efficient LEDs instead of incandescent light
bulbs for line status indication.
4.8.7 Independent key sets:
LSI also allowed smaller systems to distribute the control (and features) into individual
telephone sets that don't require any single shared control unit. Generally, these systems
are used with a relatively few telephone sets and it is often more difficult to keep the
feature set (such as speed-dialing numbers) in synchrony between the various sets.
4.8.8 Hybrid key phone systems:
Into the 21st century, the distinction between key systems and PBX has become
increasingly confusing. Early electronic key systems used dedicated handsets which
displayed and allowed access to all connected PSTN lines and stations.
Figure 4.9.3 Nortel T Series Key System Telephone
The modern key system now supports SIP, ISDN, analog handsets (in addition to its own
proprietary handsets - usually digital) as well as a raft of features more traditionally found

53. 41
on larger PBX systems. Their support for both analog and digital signaling, and of some
PBX functionality gives rise to the "Hybrid" designation.
A hybrid system typically has some call appearance buttons that directly correspond to
individual lines and/or stations, but may also support directly dialing to extensions or
outside lines without selecting a line appearance.
The modern key system is usually fully digital (although analog variants persist) and
some systems embrace VOIP. Indeed, key systems now can be considered to have left
their humble roots and become small PBX’s. Effectively, the aspects that distinguish a
PBX from a hybrid key system are the amount, scope and complexity of the features and
facilities offered.
Hybrid systems are a common tool in the financial services industry used on trading
floors. These advanced hybrid key systems generally only require attached PBXs for
interaction with backroom staff and voicemail. These systems commonly have their front
end units referred to as Turrets and are notable for their presentation of hoot-n-
holler circuits. Multiple Hoots are presented to multiple users over multiplexed speakers
to multiple locations.
4.8.9 Private branch exchange:
A private branch exchange (PBX) is a telephone exchange that serves a particular
business or office, as opposed to one that a common carrier or telephone company
operates for many businesses or for the general public. PBXs are also referred to as:
 PABX – private automatic branch exchange
 EPABX – electronic private automatic branch exchange
PBXs make connections among the internal telephones of a private organization—usually
a business—and also connect them to the public switched telephone network (PSTN)
via trunk lines. Because they incorporate telephones, fax machines, modems, and more,
the general term "extension" is used to refer to any end point on the branch.

54. 42
PBXs are differentiated from "key systems" in that users of key systems manually select
their own outgoing lines, while PBXs select the outgoing line automatically. Hybrid
systems combine features of both.
Initially, the primary advantage of PBXs was cost savings on internal phone calls:
handling the circuit switching locally reduced charges for local phone service. As PBXs
gained popularity, they started offering services that were not available in the operator
network, such as hunt groups, call forwarding, and extension dialing. In the 1960s a
simulated PBX known as Centrex provided similar features from the central telephone
exchange.
Two significant developments during the 1990s led to new types of PBX systems. One
was the massive growth of data networks and increased public understanding of packet
switching. Companies needed packet switched networks for data, so using them for
telephone calls was tempting, and the availability of the Internet as a global delivery
system made packet switched communications even more attractive. These factors led to
the development of the VoIP PBX. (Technically, nothing was being "exchanged" any
more, but the abbreviation PBX was so widely understood that it remained in use.)
The other trend was the idea of focusing on core competence. PBX services had always
been hard to arrange for smaller companies, and many companies realized that handling
their own telephony was not their core competence. These considerations gave rise to the
concept of hosted PBX. In a hosted setup, the PBX is located at and managed by the
telephone service provider, and features and calls are delivered via the Internet. The
customer just signs up for a service, rather than buying and maintaining expensive
hardware. This essentially removes the branch from the private premises, moving it to a
central location.

55. 43
Figure 4.9.4 EPABX exchange
4.9.0 PBX functions:
Functionally, the PBX performs four main call processing duties:
 Establishing connections (circuits) between the telephone sets of two users (e.g.
mapping a dialed number to a physical phone, ensuring the phone isn't already
busy)
 Maintaining such connections as long as the users require them (i.e. channelling
voice signals between the users)
 Disconnecting those connections as per the user's requirement
 Providing information for accounting purposes (e.g. metering calls)
In addition to these basic functions, PBXs offer many other calling features and
capabilities, with different manufacturers providing different features in an effort to
differentiate their products. Common capabilities include (manufacturers may have a
different name for each capability)-
 Auto attendant
 Auto dialing
 Automatic call distributor

56. 44
 Automated directory services (where callers can be routed to a given employee by
keying or speaking the letters of the employee's name)
 Automatic ring back
 Call accounting
 Call blocking
 Call forwarding on busy or absence
 Call park
 Call pick-up
 Call transfer
 Call waiting
 Camp-on
 Conference call
 Custom greetings
 Customized Abbreviated dialing (Speed Dialing)
 Busy Override
 Direct Inward Dialing
 Direct Inward System Access (DISA) (the ability to access internal features from
an outside telephone line)
 Do not disturb (DND)
 Follow-me, also known as find-me: Determines the routing of incoming calls. The
exchange is configured with a list of numbers for a person. When a call is
received for that person, the exchange routes it to each number on the list in turn
until either the call is answered or the list is exhausted (at which point the call
may be routed to a voice mail system).
 Interactive voice response
 Music on hold
 Night service
 Public address voice paging
 Shared message boxes (where a department can have a shared voicemail box)
 Voice mail

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 Voice message broadcasting
 Welcome Message
4.9.1 Interface standards:
4.9.1.1 Interfaces for connecting extensions to a PBX include:
 POTS (plain old telephone service) - the common two-wire interface used in most
homes. This is cheap and effective, and allows almost any standard phone to be
used as an extension.
 Proprietary - the manufacturer has defined a protocol. One can only connect the
manufacturer's sets to their PBX, but the benefit is more visible information
displayed and/or specific function buttons.
 DECT - a standard for connecting cordless phones.
 Internet Protocol - For example, H.323 and SIP.
4.9.1.2 Interfaces for connecting PBXs to each other include:
 Proprietary protocols - if equipment from several manufacturers is on site, the use
of a standard protocol is required.
 ISDN PRI - Runs over T1, 23 bearer channels + 1 signalling channel
 QSIG - for connecting PBXs to each other, usually runs over T1 (T-carrier) or E1
(E-carrier) physical circuits.
 DPNSS - for connecting PBXs to trunk lines. Standardized by British Telecom,
this usually runs over E1 (E-carrier) physical circuits.
 Internet Protocol - H.323, SIP and IAX protocols are IP based solutions which
can handle voice and multimedia (e.g. video) calls.
4.9.1.3 Interfaces for connecting PBXs to trunk lines include:
 Standard POTS (plain old telephone service) lines - the common two-wire
interface used in most domestic homes. This is adequate only for smaller systems,
and can suffer from not being able to detect incoming calls when trying to make
an outbound call.

58. 46
 ISDN - the most common digital standard for fixed telephony devices. This can
be supplied in either Basic (2 circuit capacity) or Primary (24 or 30 circuit
capacity) versions. Most medium to large companies would use Primary ISDN
circuits carried on T1 or E1 physical connections.
 RBS (robbed bit signaling) - delivers 24 digital circuits over a four-wire (T1)
interface.
 Internet Protocol - H.323, SIP, MGCP, and Inter-Asterisk exchange protocols
operate over IP and are supported by some network providers.
4.9.1.4 Interfaces for collecting data from the PBX:
 Serial interface - historically used to print every call record to a serial printer.
Now an application connects via serial cable to this port.
 Network Port (listen mode) - where an external application connects to
the TCP or UDP port. The PBX then starts streaming information down to the
application.
 Network port (server mode) - the PBX connects to another application or buffer.
 File - the PBX generates a file containing the call records from the PBX.
The call records from the PBX are called SMDR, CDR, or CIL. It is possible to use
a Voice modem as FXO card.
4.9.2 Hosted PBX systems:
A hosted PBX system delivers PBX functionality as a service, available over the Public
Switched Telephone Network (PSTN) and/or the internet. Hosted PBXs are typically
provided by the telephone company, using equipment located in the premises of the
telephone company's exchange. This means the customer organization doesn't need to
buy or install PBX equipment (generally the service is provided by a lease agreement)
and the telephone company can (in some configurations) use the same switching
equipment to service multiple PBX hosting accounts.
Instead of buying PBX equipment, users contract for PBX services from a hosted PBX
service provider, a particular type of application service provider (ASP). The first hosted
PBX service was very feature-rich compared to most premise-based systems of the time.

59. 47
In fact, some PBX functions, such as follow-me calling, appeared in a hosted service
before they became available in hardware PBX equipment. Since that introduction,
updates and new offerings from several companies have moved feature sets in both
directions. Today, it is possible to get hosted PBX service that includes far more features
than were available from the first systems of this class, or to contract with companies that
provide less functionality for simple needs.
In addition to the features available from premises-based PBX systems, hosted-PBX:
 Allows a single number to be presented for the entire company, despite its being
geographically distributed. A company could even choose to have no premises,
with workers connected from home using their domestic telephones but receiving
the same features as any PBX user.
 Allows multimodal access, where employees access the network via a variety of
telecommunications systems, including POTS, ISDN, cellular phones, and VOIP.
This allows one extension to ring in multiple locations (either concurrently or
sequentially).
 Supports integration with custom toll plans (that allow intra company calls, even
from private premises, to be dialed at a cheaper rate) and integrated billing and
accounting (where calls made on a private line but on the company's behalf are
billed centrally to the company).
 Eliminates the need for companies to manage or pay for on-site hardware
maintenance.
 Allows scalability so that a larger system is not needed if new employees are
hired and so that resources are not wasted if the number of employees is reduced.
4.9.3 Mobile PBX:
A mobile PBX is a hosted PBX service that extends fixed-line PBX functionality to
mobile devices such as cellular handsets, smartphones and PDA phones by provisioning
them as extensions. Mobile PBX services also can include fixed-line phones. Mobile
PBX systems are different from other hosted PBX systems that simply forward data or
calls to mobile phones by allowing the mobile phone itself, through the use of buttons,

60. 48
keys and other input devices, to control PBX phone functions and to manage
communications without having to call into the system first.
A mobile PBX may exploit the functionality available in smartphones to run custom
applications to implement the PBX specific functionality.
In addition, a mobile PBX may create extension identifiers for each handset that allow
dialing other cell phones in the PBX via their extension shortcut, instead of a PSTN
number.
4.9.4 IP-PBX:
An IP PBX handles voice signals under Internet protocol, bringing benefits for computer
telephony integration (CTI). An IP-PBX can exist as physical hardware, or can carry out
its functions virtually, performing the call-routing activities of the traditional PBX or key
system as a software system. The virtual version is also called a "Soft PBX".
4.9.5Spider EPABX system:
Spider EPABX is the latest in telecommunication, based on micro-processor technology,
in which the switching matrix is based on CMOS chips providing high reliability and low
power consumption Plug-in, modular PCB construction ensures immediate up gradation
and repairs.
Figure 4.9.5 spider EPABX system

61. 49
4.9.5.1 Operating environment:
The system is suited to Indian conditions and air conditioning is not required.
4.9.5.2Cabling:
The system runs on a single pair cable for each extension. Thus installation re-touted
extensions etc. are easily possible.
4.9.5.3 Features:
 Intercom
 Direct outward dialing
 Bar on trunk dialing
 Bar on long distance STD calls
 Call pick up from any extension
 Console less operation
 Consultation call hold
 Call transfer
 Call rotation
 Conference
 Auto call back
 Barge in override priority
 Auto off ring, Busy and dial tone
 Follow me call forwarding
 Night service
 Music on hold
 Extension ringer optional

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4.9.5.4 Specifications:
Table no 1 specification of spider EPABX system
4.9.5.5 MS48C PBX System:
MS48C provides large scale communications systems facilities to the small businesses
and homes with its capacity of 48 Analog Ports, 36 IP Ports, over 100 programmable
usage features and remote programming feature for servicing and maintenance services.
 Basic capacity is 4 Analog Lines, 12 Analog Extensions, 4 IP Lines and 8 IP
Extensions. The system may be expanded to 4-12 Analog Lines, 12-40 Analog
Extensions, 12 IP Lines and 24 IP Extensions.
 Over 100 programmable user features
 Modular expansion and adding features
 Remote programming for service and maintenance operations
 Display of number or name of the caller on caller ID (CID) phones(Optional)
Trunk Capacity Maximum 5 P and T Lines
System Capacity Minimum 8 Lines Maximum 64 Lines Total
Technology CMOS Switching Matrix controlled by 8085 µP
Trunk Line Resistance 600 Ohms 1500 Ohms Max
Dialling Speed 10 pps
Speech Paths 7 Links
Cabling Method 2 Wire System
Input Voltage 220 +- 10% V AC, 50 Hz
Power Consumption Less than 50 Watt
Telephone Instruments Standard 2 Wire Decade Pulse type

63. 51
 Sending and receiving text messages (SMS) from landlines to all compatible
phones(Optional)
 Ability to use the features of the work phone as an extension to the PBX from
anywhere with an internet connection at any time
 Provides video call support.
 Multimedia communication
 Provides economy and efficiency in communication.
 Mobility by IP Phones, Softphones, Wi-Fi Phones, IP DECT Phones or VoIP
supported Smartphones. System provides mobility in business life with its support
for communication regardless of the location. They also facilitate the access to the
mobile employees of the organization.
 Presence, instant messaging support
 System security is provided with a Firewall.
 Call security (sRTP/TLS IP encryption) ensures secure audio communication
 Provides high audio quality in IP calls. Ensures continuity of the audio quality by
monitoring the performance on the network and taking necessary precautions with
its QoS support.
Figure 4.9.6MS48C EPABX system

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4.9.5.6 Extension Features:
 Hot line
 Intrusion
 Music on hold
 Call transfer
 Call forwarding (external line/extension)
 Line-to-Line connection
 External line authorization restriction
 Auto-answer external line calls
 Direct Transfer of Lines to Specified Extensions in Case of Power Failure
 Flexible night service
 Facsimile forwarding
 Delayed emergency line
 External music source input
 Reminder Service
 Extension / Line Groups
 Door opening
 Conference
 Case ring
 Busy Extension Signaling
 Common and private pool
 Automatic calling
 Automatic line check
 Programmable external line call duration
 Do not disturb
 Selective line access
 Serial transfer
 Call back
 Redial
 Telephone lock
 Remote programming

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 SIP extension and line support
 High audio quality in IP calls
 Video call support
 G.711, G.729 A/B, G.723.1, G.726/G.727 codec support
 T.38 fax-over-IP support
 RTP/RTCP
 RFC 2833, SIP INFO and in-band DTMF detection, generation
 Dynamic jitter buffer
 Packet loss compensation
 Automatic gain adjustment
 Silence detection
 Echo canceller
4.9.5.7 Solution:
 Least cost routing (LCR) feature
 Accessing the extensions and leaving messages without interrupting the operator
using the auto-attendant and voicemail features (optional)
 More productive and cost-efficient communication by monitoring the rate and
time information on phone traffic with the computer monitor thanks to the Net-
CM reporting software (optional)
 Usage of many PBX features rapidly and effectively by monitoring the key-in
operations performed by the user on the phone from the computer monitor thanks
to the Net-Console (CTI) software (optional)
 Communication with the door from any extension phone in the office and opening
the door by entering a key in the phone with the doorphone unit (optional)
 Using numerous features of the PBX with the feature phone set (optional)
 Firewall
 Call security (sRTP/TLS / IP encryption)
 Mobile extension
 QoS

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4.9.5.8 Specification:
Capacity:
 MS48C = Total 48 Analog ports + 1 door phone channel + 36 IP Ports (Optional)
 4 / 24 Analog lines
 12 / 64 Analog extensions
Control:
 Main processor: AM188ES Processor
 EPROM (1 Mbit)
 EEPROM (4 Kbyte)
 512 Kbit Static RAM with NiMh Battery
 AC494 DSP
Switching:
 CMOS switching circuit with space division multiplexing
 Ethernet switching
 Tones: Standard
Power:
 230 VACS – 50 Hz.
Dimensions:
 39 cm x 48 cm x 13 cm
4.9.5.9 MS26 Series PBX Systems:
MS26S and MS26C provide large scale communications systems facilities to the small
businesses and homes with its capacity of 2 analog lines / 6 analog extensions, over 100
programmable usage features and remote programming feature for servicing and
maintenanceservices.

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MS26S:
 Over 100 programmable user features
 Convenience of remote programming for service and maintenance operations
MS26C:
Additional to the features of MS26S model:
 Display of number or name of the caller on caller ID (CID) phones.
 Sending and receiving text messages (SMS) from landlines to all compatible
phones.
 Least cost routing (LCR)
 Accessing the extensions and leaving messages without interrupting the operator
using the auto-attendant and voicemail features (optional)
 More productive and cost-efficient communication by monitoring the rate and
time information on phone traffic with the computer monitor thanks to the Net-
CM reporting software (optional)
 Usage of many PBX features rapidly and effectively by monitoring the key-in
operations performed by the user on the phone from the computer monitor thanks
to the Net-Console (CTI) software (optional)
 Communication with the door from any extension phone in the office and opening
the door by entering a key in the phone with the door phone unit (optional)
 Using numerous features of the PBX with the feature phone set (optional)
4.9.6.0 IPV10 and IPV20:
 Supports major IP communication features in analog and IP platforms.
 Remote offices/branches can be operated as a single system with the IP Bridge
established between the different departments of the company.
 IP communication performed over the IP bridge to be established provides
reasonable savings in communication costs.

68. 56
Models:
KAREL IPV10
Supports 20 IP Ports and 4 Analog Ports
(a)
KAREL IPV20
Supports 40 IP Ports and 16 Analog Ports
(b)
Figure 4.9.7 (a) KAREL IPV10 and (b) KAREL IPV20
Also, these systems provide the opportunity to create unified systems and to expand
since multiple PBXs can be operated as a single system.
Unified StructureIP and analog extensions can be used in the same system without any
need for an additional infrastructure. The feature that allows becoming a system
extension from different points using softphones, desktop IP phones, videophones, VoIP
compliant mobile phones, IP DECT and analog sets provides flexibility and economy.
IPV10 and IPV20 integrate several product functions such as PBX, IP-PBX, and IP-
Gateway etc. in a single structure. System software runs on Linux operating system and
has features of the open source software architecture. This allows integrating additional
applications to the PBX easily besides the already integrated applications on the PBX.

69. 57
Peripherals That Can Be Used with IPV10 and IPV20 Communication Systems
IPV10 and IPV20 support Proprietary IP and SIP for the extensions and both SIP and
H.323 protocols and new generation audio compression algorithms for the Lines:
 Standard SIP and Karel SIP Phones
 Video SIP Phones
 WiFi SIP Phones
 Smartphones
 IP DECT System (IP DECT base stations and IP DECT handsets that support SIP
signaling protocol)
 Other terminals with SIP support
IP Communication ApplicationsExtensions are not required to be in the same location
with the PABX. Extensions can communicate continuously with access units that can
communicate over IP such as IP phones, IP soft-phones, WiFi phones or VoIP enabled
smart phones etc. from any point and at any time.
Remote Office ApplicationsIn companies with offices in different locations, it is possible
to become an extension of the exchange in the head office from anywhere with Internet
connection without any additional equipment. An extension in a branch office can get
connected to the exchange in the head office directly over Internet with an IP phone, soft-
phone, WiFi phone, IP DECT phone or a VoIP enabled smart phone.
WiFi and IP DECT extensions are also supported by the system just like the standard SIP
extensions. Multiple KAREL IPV10 and IPV20 PBXs can call each other over IP, and
thus, company communication networks with higher capacities can be established.
Video CallAll IP extensions connected to IPV10 and IPV20 Communication System can
make video calls between themselves or through external IP lines using videophones,
special sets or smart phones.Extensions of KAREL IPV10 and IPV20 IP PBX can
communicate over extension numbers regardless of their location. Communication can be
established from any location by becoming an internal extension of the system with an

70. 58
access unit such as IP phones, soft-phones, IP DECT, WiFi phones or VoIP enabled
smart phones. These extensions can utilize all centralized applications. And, there is a
single numbering plan covering the entire system.With an IP DECT system that can be
integrated to the exchange, it is possible to use the same handset without changing its
extension number both in the head office and in any other location containing a base
station integrated with the exchange through the Internet.New generation VoIP enabled
smart phones with mobile extension applications allow making calls as an IP extension of
the exchange, answering incoming calls, listening to voicemail and utilizing all exchange
services offered to IP extensions. IPV10 and IPV20 provide users the flexibility to
continue communication and remain available at any location with Internet connection as
an exchange extension by means of a soft-phone or VoIP enabled smart phone over IP,
3G, WiFi or XDSL connections. Unified Communications Applications
- IPV10 and IPV20 provide unified communication benefits such as voice-over-IP, fax-
over-IP, voice recording, conference call, video call, and voicemail to e-mail, monitoring
presence, instant messaging, remote extension and remote office.
Voice messages, call records and system fault notifications can be sent to the specified e-
mail addresses with the aid of integrated voicemail and e-mail applications. Therefore, it
is possible to access such data and voicemails from any location. KAREL IPV10 and
IPV20 IP PBX provide convergence solutions for fixed line and mobile communications
with mobile extensions used on smart mobile phones. As every VoIP enabled mobile
phone with mobile extension software can be defined as an extension to the system,
extensions can answer incoming calls from such phones, listen to their voicemails and
utilize all IP extension services provided by the exchange.Presence allows other
extensions to see whether the extension is available, busy, active/passive and the special
status that is set by the person himself/herself with a text entry. Thanks to this feature, it
becomes possible to access the relevant person with the quickest and most suitable
method. All extensions on IPV10 and IPV20 PBXs can monitor their busyness status
easily.

71. 59
Instant MessagingIPV10 and IPV20's Instant Messaging features allows extensions to
communicate with each other using instant text messages; and therefore communication
occurs instantly and there is no waiting period unlike the e-mail communication

72. 60
CHAPTER 5
CHECKLIST FOR BUYING EPABX
5.1 Requirement Analysis:
A detailed analysis of the EPABX feasibility in your office needs to done based on the
following factors:
 How many persons will be using the phone at a given time.
 The least costing system, if making a lot of outgoing calls is expected.
 Suitable battery backup depending on power supply conditions.
 Automated office calls with the IVR (Interactive Voice Response) and CTI
(Computer Telephony Integration).
5.2 Size of the EPABX:
The size of an EPABX system refers to the number of direct lines and extension lines
needed. This requirement will be calculated based on the number of posts in the
organization that require constant telephone connectivity.
5.3 PBX Features and Benefits:
The benefits of the EPABX system needs to be carefully analyzed in respect to how the
incoming calls will be attended and processed, long distance calls count, and how to
handle misuse of the system.
Also consider PBX features needed like, call transfer, caller id, call conferencing, auto
attendant, call forwarding etc.
5.4 Future Upgrades and Price:
Upgradability and the cost of expanding the EPABX system needs to be considered as
well.
Price is another important factor to consider as India is a very price sensitive market. If

73. 61
you are choosing the cheaper PBX, then it should not compromise on the quality. There
are many supplementary costs like wiring, power supply backup, battery, rack, etc.
Maintenance costs also need to be taken into account.
5.5 Selecting the EPABX System Provider:
Opt for an EPABX system only from authorized dealers or distributors of the
manufacturers. This will ensure that essential support and service of the equipment’s.
You can also ask for references from other organizations about the working and
suitability of their EPABX system to study the suitability for your organization.
Careful thought about the above criterions will help you make a wise decision on the type
of EPABX system that is actually required for your office, thus, increasing the value of
the business communications at affordable costs.

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APPENDIX A
TECHNICAL SPECIFICATIONS
FOR
ISDN EPABX SYSTEM
SCOPE OF WORK
FOR
ISDN EPABX SYSTEM
SECTION – 1

75. 63
INTRODUCTION:
CDRI has taken up a project for Construction of new Campus at Sitapur Road,
Lucknow. This portion of tender is for works related to supply, installation,
testing & commissioning of ISDN EPABX System (main) with wired capacity of
1200 ports (analog & digital extensions), PRI lines, .BRI ports to be installed in
administration building and EPABX system with wired capacity of 100 ports in
guest house building for new CDRI campus at Lucknow.
SCOPE OF WORK:
In general the works to be performed under this contract shall comprise of:
 Design, engineering, manufacture, inspection & testing, supply, transportation to
site, storage, installation, system integration, testing & commissioning of the
following items with all required accessories.
 ISDN EPABX System (main) in administration building.
 EPABX System in guest house and its connectivity with main EPABX in
administration building along with associated cabling work. (Distance between
main exchange and guest house is approximately 350 meters).
 Required MDF/IDF and associated wiring/cabling
 Telephone sets
 The bidder shall be responsible for engineering and providing all materials,
equipment and services specified or otherwise, which are required to fulfill the
intent of ensuring operability, maintainability, completeness and reliability of the
total work. Item wise bill of quantity (BOQ) indicated in price schedule is based
on which work shall be executed. Any other equipment, material, component,
accessories which are not specifically mentioned in price bid and technical
specification but necessary for satisfactory installation and trouble free
operational and maintenance of the equipment / system adopting good
engineering practice shall be in the scope. The offered equipment shall be new,
employing proven and established latest technology suitable for Indian conditions.
 Providing complete design, engineering data, BOQ, detailed drawings, schemes,
commissioning procedure, O&M manuals, catalogue, reference documents etc.

76. 64
for EPI/CDRI ‘s review/reference / records in requisite sets of hard copy and
soft copy.
 Installation, testing & integrated commissioning of the complete system
 Execution of works shall be as per tender conditions & technical specification,
relevant applicable IS, ITD/DoT requirements code of practice in conformity
with the Indian Electricity Act , 1910 and the Indian Electricity rules 2005
amended up to date, CPWD specifications for Electrical works Part - I (internal)
2005, Part -II (External) 1994, Part IV as amended up to date of receipt of tender,
CDRI requirement and requirements of the Local Electricity supply authority and
other regulations and safety codes in the locality where the equipment will be
installed.
 Ensuring interlocking/integration/interconnection among various
equipment/system, earthing of equipment and safety aspects as per the
requirements.
 All Statutory approvals / license for the equipment(s) / system(s) shall be
obtained by the successful bidder as needed including approval of relevant
drawings, approval for the entire installation and after completion of work, as per
the approved drawings. Cost for obtaining such approvals from statutory
authority/DoT/TEC shall be borne by the bidder.
 Effective co-ordination with the other agencies to carry out the work smoothly.
 Proper handing over of the installations in satisfactory working conditions along
with required as built drawings, documents, maintenance tools /tackles and items
as specified in the tender.
 The work shall also include all incidental job connected with the installation of
equipment’s.
 All the equipment except battery shall be designed considering 45 C as ambient
temperature. Battery shall be designed considering minimum ambient

77. 65
temperature (5C). Where equipment are installed outside and exposed to direct
sun-rays, rigorous weather conditions under which they are required to operate
shall be taken into consideration.
 Any work like chipping/breaking of existing structure like walls, floors,
fabrications etc. with prior approval of the EPI/CDRI’s representative.
 In case any existing structure is affected/damaged due to the installation work,
the repairing to the same shall be done to the satisfaction of the EPI/CDRI’s
representative without any extra cost.
 Any modifications/rework required on account of wrong practices shall bedone
without any extra cost.
TECHNICAL REQUIREMENTS AND STANDARDS:
The specification defines the requirements for a continuous duty, highly reliable,
latest and state of art technology EPABX Systems for effective
intercommunication in the CDRI campus.
All equipment of system shall comply in all respects with the requirements of the
latest edition of the relevant codes and Indian Standard. The technical
specifications for the system to be executed are enclosed. Items which are not
covered under the technical specifications and are required for completeness of
the system shall be executed as per latest IS/ IE rules and Indian telecom
department requirements
The EPABX system shall be TEC/DOT approved and conform to the latest issue
of relevant applicable International standards/IEC standard /Indian standards for
design, manufacturing, safety, inspection and installation.
SITE CONDITIONS:
The main EPABX shall be installed in the EPABX room in administration
building and EPABX for guest house shall be installed in guest house reception
area.

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Max. ambient temp -- 45°C
Min. ambient temp -- 5°C
Max. R.H. -- 90%
Min R.H. -- 20%
Altitude above means sea level -- 1000 mtrs.
POWER SUPPLY:
Power Supply
230 V + 10% , 50 Hz + 3%
415 V + 10%, 3-phase, 4 wire, 50Hz + 3%, effectively
earthed.
INSPECTION OF SITE:
The bidder to inspect and examine the site and its surrounding and shall
satisfy as to the nature of the ground and sub soil, the quantities and
nature of work, materials necessary for completion of the work and their
availability, means of access to site and in general to obtain all necessary
information as to risks, contingencies and other circumstances which may
influence or affect his offer. No extra claim consequent on any
misunderstanding or otherwise shall be allowed.
PRICES:
 Price shall be Inclusive of all taxes & duties, what so ever including
excise duty, sales tax, VAT, service tax, octroi (if any), work contract
tax, commissioning spares, labor, tools & plants, packing, freight/
transportation & insurance up to the site, loading, unloading, fee (s) for
testing, license, inspection, documents, etc., where applicable.

79. 67
 CDRI does not give any confessional forms/ certificates/ permits towards
any taxes, duties & other levies like sales tax, customs duty, road taxes/
permits, etc.
 Prices shall be firm throughout the contract period.
BOQ QUANTITIES:
The quantities given in the tender BOQ/price bid may vary as per the site /
system/CDRI requirements. Only required items & quantities are to be supplied/
installed. The rate shall remain valid for any variations in the estimated quantities
given in price bid. The bidder shall take detailed site measurements for the items
like supply of power cables; earth strips/wire etc.before placing purchase
order/taking procurement action.
MAKES:
 In general make of various items shall be as per the recommended vendor list
enclosed. Where makes have not been indicated in the list, the items shall be
of ISI marked.
 Sample of the items or makes or the items for manufacture/ supply/ use in the
work irrespective of appearing in the approved list shall be got approved from
Engineer- in-charge before incorporation.
SPARES:
The bidder shall indicate and include in quoted price, all the start-up and
commissioning spares and furnish the complete list of recommended spares with
unit rate for 3 years of normal operation and maintenance for the equipment’s.
NEW MATERIALS:
All equipment, materials used in the work shall be brand new and free from
manufacturing defects.

80. 68
REPLACEMENT OF DEFECTIVE/ DAMAGED ITEMS:
All defective/damaged items shall be replaced with the good ones without any
extra cost to purchaser (during guarantee period)
TOOLS & TACKLES:
 All the required special tools & tackles for executing this work shall be in the
scope .Bidder to furnish the list of such tools alongwith the offer.
MAN POWER:
 Authorized, experienced, competent work force shall be deployed with
competent supervision.
 They should possess requisite qualifications/ valid permits/ license/
competency certificates to work.
 The engineer shall have minimum qualification of degree in engineering.
Whereas supervisor shall have minimum qualification of diploma in
engineering and technicians shall have minimum ITI.
QUALITY OF WORK & WORKMANSHIP:
The quality of work, workmanship, finishing etc. should be satisfactory to the
CDRI / EPI.
ACTION PLANS/ PROGRAMME/ WORK SCHEDULING/ CPM & PERT
CHARTS / PROGRESS REPORTS/ BAR CHARTS /REPORTS & RECORDS:
The successful bidder shall submit necessary reports during various stages of
contract which include action plans/ programme/ work scheduling/ CPM (Critical
Path Method) & PERT (Project Evaluation and Review Technique) charts /
progress reports/ bar charts and various records, statements, reports, documents
related to the work.
A comprehensive action plan/programme/schedule has to be made based on the
completion period, inter related activities and got approved from CDRI.

81. 69
REVIEW MEETINGS/ SITE INSPECTIONS:
As and when required the successful bidder shall attend the review meetings and
take necessary actions with regard to the pending works, targets, co-ordination
with other agencies.
Senior/ competent officials/ engineers who can take decisions and implement
from their side to take stock of the situation and do the needful shall also make
regular site inspections.
PRIOR APPROVAL FOR DISPATCH SCHEDULE:
Dispatch schedules shall be informed and got approved from engineer in charge
before dispatch of the materials.
TESTING AND INSPECTION:
 All equipment/systems to be supplied shall conform to the applicable relevant
standards. The Bidder/vendor shall furnish the reports of all the type tests
carried out/ conducted in last five years on identical/similar
components/equipment/systems. In case bidder/vendor is not able to submit
report of type test conducted in last five years or in case type test reports are
not found to be meeting the specifications/relevant standard requirement then
all such tests shall be conducted under this contract by the bidder/vendor free
of cost to the purchaser and reports shall be submitted for approval.
 All acceptance and routine tests as per the relevant standards shall be carried
out by the supplier and charges for such tests shall be deemed to be included
in the bid price. All the routine test/acceptance test shall be carried out in the
presence of the inspecting officer from EPI/CDRI./their representative.
 All major items to be supplied shall be factory inspected. The decision to
inspection/waiver shall rest with the EPI / CDRI.The list of approved makes
enclosed is indicative, CDRI/EPI can add/delete/modify the same in the
interest of organization/work from time to time considering cost, quantity,
significance, completion schedules etc.

82. 70
 At least 15 days advance notice to be given for factory inspection and all
internal test reports to be submitted with inspection call while inspection call
is given, the actual status and details of test to be offered shall be
communicated. Relevant applicable Indian standards & International
standards shall be made available during inspection.
 If any equipment/material fails in the tests conducted during factory
inspection, necessary rework/replacement shall be done and equipment shall
be re-offered for inspection without any extra cost to purchaser. Further, the
traveling, boarding & lodging expenses of inspecting officer for re-inspection
shall be recovered from the supplier’s bills as per the CDRI’s rules.
PACKING/ TRANSPORTATION/ HANDLING:
 Equipment/ materials shall be properly packed with appropriate packing
materials & means. Special care shall be taken for fragile items. Item
description, qty, code, instructions etc. should be marked for easy
identification etc.
 The equipment/ materials should be transported by appropriate transport
mode up to the site/ destination.
 Due care should be taken for loading, handling, unloading, shifting, lifting,
jacking etc. by suitable means like Cranes, Fork lifts, Chain pulley blocks,
mechanized means etc. and experienced man power.
 Relevant documents shall be accompanied with the items.
SECURITY NORMS/GUIDELINES:
The successful bidder shall obtain necessary entry pass/ token/ identity card from
CDRI/BCAS/CISF/CRPF, who is in charge of security matters, for their
workforce. and fulfill all the formalities viz. police verification, photographs,
addresses and keeping in safe custody and bear the fee, if any.

83. 71
DRAWING & DOCUMENTATION TO BE SUBMITTED WITH BID:
Following information and documentations in addition to what has been asked for
in respective equipment specifications shall be furnished by the bidder:
 Technical particulars, catalogue & literature for the equipment.
 Performance certificates of all major equipment.
 Type test certificates.
 Q-SIG compliant certificate
 Valid TEC approval in the name of manufacturer for the make and model no.
offered.
 List of Past contract for similar type of equipment and certificates from
purchaser for successful installation & commissioning.
 GA drawings of all major equipment.
 Time frame of major activities including Bar chart.
DRAWING & DOCUMENTATION TO BE SUBMITTED BY SUCCESSFUL
BIDDER AFTER AWARD OF CONTRACT:
Following information and documentations in addition to what has been asked for
in respective equipment specification shall be furnished by the successful bidder
in requisite no of hard copy and soft copy after award of contract for
approval/reference/record of the purchaser.
 Layout drawing showing location of equipment, cable routing, etc.
 Earthing layout showing connections to equipment..
 Wiring diagram and cable termination details.
 Write-up on the features of the system.
 Civil foundation and structural drawing for Installation.
 Bill of materials for hardware and software.
 System Configuration
 Operating manual on EPABX system and accessories.
 All other required drawings/documents/technical information required during
various stages of works shall be submitted by the vendor as and when
required by the purchaser.

84. 72
 All drawings to be submitted shall have sufficient detail to indicate the type,
size, general arrangement & foundation drawing, weight, the external
connections, fixing arrangement required, the dimensions required for
installation and interconnections with other equipment and materials,
clearances and space required between various portions of equipment and any
other information specifically requested.
 The successful bidder shall provide a complete bar chart based on the time
period of the completion of the project. within 2 weeks of award of work The
bar chart shall elaborate procurement, installation, testing & commissioning
of the complete system.
TOOLS & TACKLES:
Wherever special tools & tackles are required for operation & maintenance of
units/systems, the same shall be provided.
STATUTORY LAWS/RULES/APPROVALS/LICENSE:
The system supplier/agency shall abide by the relevant statutory rules, laws, and
guidelines and arrange for the approvals, if any required. Those include adhering
to labor laws, abiding local electricity rules etc.
Where ever formal approvals/ license are essential, clearance by the local
authorities/telephone department etc. shall be arranged by the successful bidder
FEES FOR TESTING/CALIBRATION/APPROVALS/LICENSE:
Unless otherwise specified, the fees/charges involved for this purpose shall be
borne by the successful bidder.
SITE TESTS/ PERFORMANCE TESTS:
Necessary site tests/ performance tests shall be conducted on the equipment to
ascertain the functional / design/ site requirements. Reports shall be prepared
recording the various values, parameters, observations, settings made etc. In case
of unsatisfactory results, the same shall be replaced/ rectified as per the
requirement without any extra cost.

85. 73
HANDING OVER/ CERTIFIED DATE OF COMPLETION:
After the satisfactory commissioning of the entire system, the system shall be
observed for 15 days. After this satisfactory trial period, the system shall be
handed over officially and completion date recorded by Engineer-in- charge with
all the prescribed formalities for handing over.
This date shall be reckoned, as the certified date of completion and the defects
liability period shall commence from this date.
Until the handing over of the installation, the responsibility lies with the supplier
for safety, upkeep etc.
TRAINING/ FAMILIARIZATION ABOUT OPERATION & MAINTENANCE:
Proper training/ familiarization regarding operation & maintenance of the
equipment /system shall be given to CDRI staff by the successful bidder.
COMPLETION PLANS:
On completion of work, the 10 sets of following as built drawings/documents to
be submitted to the purchaser/user.
 General Arrangements, Layout drawings with dimensions, plans, sections
etc.
 Bill of Quantities indicating makes, Technical specs, quantity etc.
 Data Sheets
 Details of Inventory
 Equipment name plate details
 Instruction / Maintenance Manuals
 Test Certificates (Factory Tests, sites Test)
 Guarantee/ warranty Certificates (where applicable)
 Other documents/ drawings as per the instructions of Engineer-in- Charge.
 Keys, tools etc.
 Other drawings/documents mentioned at clause no. 24.0 above.
DEFECTS LIABILITY PERIOD:
Defects liability period shall be from the certified date of satisfactory
completion & handing over of entire work to Engineer-in-charge of work.

86. 74
During this period, the supplier shall hold himself responsible for reinstallation or
replace with good ones free of cost to the CDRI in respect of any defective
item/material/equipment/component supplied and installed. The supplier shall
bear all the cost involved for supply, transportation and installation etc. of such
items.
GUARANTEED PERFORMANCE:
The performance figures quoted in Guaranteed Technical Particulars shall be
within the tolerance permitted by relevant Indian Standards unless otherwise
stated in Technical Specification. In case of failure of the equipment to meet the
guarantee parameters the equipment may be liable for rejection.

87. 75
APPENDIX B
TECHNICAL SPECIFICATIONS
FOR
ISDN EPABX SYSTEM
SECTION – 2

88. 76
TECHNICAL SPECIFICATIONS OF THE ISDN EPABX SYSTEM
Scope:
There is a requirement of EPABX facility for the new CDRI campus at Lucknow.
The EPABX systems shall be installed in administration building and guest house.
The scope of work shall be design, engineering, manufacturing, inspection,
supply, installation, testing and integrated commissioning of Digital ISDN
compatible EPABX system (main) at first floor of administration building and
EPABX system at guest house with gateway connectivity to main EPABX over
fiber (IP), required MDF/IDF, interconnecting cables and termination of
internal/external cables to MDF/IDF.
System Design Requirements:
 EPABX system shall be designed to use intercom, direct line, ISDN, DECT,
video conferencing with today’s state of art technology, capable of supporting
analogue, digital, and the IP phones or PC based IP soft phone with suitable
client software. The offered system shall be the OEM’s latest model available
with the latest operating system software release. The system shall have
capacity to expandable upto 3000 ports (min.) in future.
 The operating system of EPABX shall be Linux based with hardened to avoid
any virus attacks.
 For easy integration /interoperability with third party applications the offered
system shall have open standards for its operating system, call processing,
signaling & networking. There shall not be any proprietary/vendor’s specific
protocols in operating system, call processing, signaling & networking.
 The system shall be equipped with minimum 1 GB RAM and 80 GB HDD.
 The main EPBAX System shall have 700 analog extensions (with wired 1000
extensions and 48 digital extensions (with wired 96 extensions.), 48 CO lines
(with wired for 96 line connections), 2 ISDN PRI lines (30 channels) with
provision for 4 PRI lines and 8 BRI ports with provision for expandability
features.
 Guest House EPABX shall have 48 extensions expandable up to 96
extensions.

89. 77
 The main & guest house EPABX system shall be provided with back-up
power for 8 hrs. Run. Main system shall have the call billing software to get
details of calls made by each extension through EPABX and other features.
Other required software packages for operating and maintaining the system
shall be provided.
 Double dedicated earthing shall be provided for the EPABX equipment,
power supply unit and MDF/IDF.
 The system shall be modular in design and shall be based on standard
protocols. It shall work under the internationally recognized networking
protocol Q-SIG.The equipment shall be capable of maintaining it guaranteed
performance when operating continuously for 24 hrs a day and 365 days a
year under the following environmental conditions.
Operational temperature — 5ºC to 45ºC
Humidity (RH) — 20% - 90% (Non-condensing)
The EPABX system shall be compatible with the public switched telephone
network of BSNL/other companies (service provider) and shall be approved
from TEC/DOT for the specified configuration. The system shall have the
flexibility and upgradeability features without replacing major equipment
elements.
 The architecture of the EPABX shall be capable of seamless migration to its
maximum capacity by simply adding peripherals cards on the same set of
cards and CPU without compromising function/features of the system.
 EPABX shall have true hot standby duplicated CPU, common control cards &
Power supply and it shall be designed to meet latest technology with all
advanced features and expandability provision.
 The EPABX shall be provided with all the required hardware & software for
connecting video conferencing equipment over BRI channels.

90. 78
 The OS of the EPABX shall be Linux based and protected against
loss/alternation of memory due to power failure/unauthorized command or
due to any other faulty condition.
 The OS of the system, the access to the various interfaces of the system, IP
calls and the signaling links from system to the gateways should be secured.
The system should be able to provide security violation alert on some
predefined endpoint. The system should also monitor and report the following
types of security violations:
a. Login violations
b. Authorization code violations
c. Station code security violations.
 It should be possible to reach the capacity of main system (3000 ports minimum)
of the switch without any up gradation of the CPU & need of additional CPU.
 The system shall provide non-blocking digital path for voice and data
communication. The system shall also offer an in built Ethernet port management
Standards:
System shall be designed as per relevant international standards/ equivalent
applicable Indian standards and safety measures - IEC complaint, TEC, CCITT,
ITU complaint.
The valid TEC/DoT approval for make and offered model should be submitted
along with the offer for EBABX system DID facility, ISDN PRI/BRI etc.

91. 79
EPABX System Requirements:
A. Technical Parameters
S.NO
DESCRIPTION SPECIFICATION
DETAILED
COMPLIANCE/
DATA TO BE
FURNISHED
BY BIDDER
1 Technology Latest Convergence Technology using fully
digital employing SPC using PCM/TDM, IP
technologies with 100 % non-blocking
characteristics, ISDN compatibility, VoIP
switch, conforming to latest ITU-T (CCITT)
standards.
2 Processor Used Pentium microprocessor (latest version) with
minimum 32 bit processor
3 BHCA Minimum 250000
4 Run distance
(a) Analog
3000 meters
(b) Digital 1000 meters
5 FCBC FCBC with SMF batteries back up for the
complete system at full load in the main
campus building for 8 hours during power
failure
6 Redundancy Hot Standby, Hot Swappable, Duplicated
control cards and duplicated power supply unit
. No single point of failure and no dropping of
established calls even during changeover of
duplicated cards
7 Wireless Telephony
Services
System shall have integrated DECT capability.
Campus – wide wireless solution
DECT base station should support the 8
simultaneous voice and up to 12 signaling

92. 80
channels.
DECT phone shall have all the common
features.
8 Network Features System shall comply and work under the
recognized international telephone standards
Q-SIG. OEM should be member of ECMA
9 Auto Attendant Auto attendant facility for 16 ports
simultaneously.
10 Voice over IP System should have in-built VoIP solution.
VoIP solution should meet all latest protocols
and standards as below:
- IP Phones
- IP soft phones
- H.323 compliant standards
11 Conference Conference facility for up to 6 parties with any
combination of Internal and External
(minimum 20 Groups)
12 TEC Approval System should be TEC approved. Confirming
to ITU & CCITT standards
13 Standard Confirming to DoT/ITU & CCITT Standards
14 Approvals Copies of valid TEC approvals in the name of
manufacturer for make and model offered.
( Bidder to submit)
15 Make & Model Complete technical literature on offered make
& model. (Bidder to submit).
16 Capacity to be used Main EPABX
- 700 Analog Extension
- 48 Digital Extension
- 48 P&T Lines

93. 81
- 2 ISDN PRI Line
- 8 BRI Ports
System shall have universal ports
Two PC based console
2 nos 24 ports LAN switches supporting SM
fiber cable (6core) to be used for connecting
main system and remote gateway on IP.
Auto attendant with 16 ports
UMS for voice ( 750 users & 16 ports UMS)
Guest House EPABX with all standard
features
- shall have independent CPU
- 48 Analog extension
- 10 P& T Lines
- System shall have universal ports
17 Safety Measures The offered system shall meet the international
standards (IEC)
19 Administration System shall have remote maintenance facility
20 Video Conferencing Video Conferencing shall be possible.
21 Voice Mail The offered system shall have an integrated
voice mail facility of 16 ports with storage
facility. Voice Mail system shall be of same
make as exchange.
22 Integrated line
testing & diagnostic
feature
System shall have integrated line testing &
diagnostic feature. This facility shall provide
information about short circuit, open circuit,
high voltage on each line.
23 Call Billing
Software
Shall be provided.
24 Computer telephone System shall have CTI facility.

94. 82
integration
25 Gateway for the
Guest House
The guest house shall have an independent 100
ports PABX module with provision for
gateway connectivity to the main PABX. And
10 analog connection to terminate at the guest
house for interfacing with the intercom system.
Gate way shall have the following capabilities:
a. Gateway shall be standard 19” rack
mountable
b. The interface to control network shall
be possible via 10/100 base T interface
and shall be possible to have it on the
LAN infrastructure
c. Gateway shall support analog, digital,
CO trunk card, PRI/BRI trunk card etc.
d. All the tone generation and the tone
detection shall be local to the gateway
e. Gateway shall have dual redundant
power supplies.
f. In case link of the gateway to the main
system goes down. Gateway shall
provide local survivability with basic
telephony features to all the user of the
guest house.
g. Gateway shall have all the
routing/switching features.
26 Tools/tackles for
Maintenance
Multi-Meter, Crimping Tools, Testing jack/
Krone tool etc. (Bidder to furnish the complete
list)
27 Diagnostic Shall be provided
Table no 2 EPABX technical parameters
The offered system shall have the following features:
 System shall have the client / server architecture between the main control and the port
shelf controls.
 System shall be based on universal port architectural & shall not impose any restriction
whatsoever in terms of slot uses for particular functional benefit.

95. 83
 System shall have minimum redundancy of CPU, main memory, secondary memory,
tone generator, main power supply, shelf power supply, ringer power supply units, shelf
controller etc. by way of duplication (multiple modules).In case main CPU fails the
established call shall not get disconnected, and the redundant CPU shall take over
seamlessly and provide the system function.
 Redundant Controls, all line and trunks cards shall be hot swappable i.e. it shall be
possible to remove and put back these modules from the system in power on conditions.
 System shall support VoIP solutions as an integral part of the system.
 System shall be fully complaint to VoIP standards like H.323 and SIP / applicable
international. Bidder to give clear compliance for the requested standards.
 System shall support AUTOMATIC ROUTE SELECTION (ARS) and LEAST COST
ROUTING (LCR) features to route the calls based on priorities related to user profile,
tariff and network availability, along the most cost effective path. This service will be
transparent for users and irrespective of the physical carrier connection.
 In the night mode when the operator is not present at the console, the direct line should
be routed to different extensions for incoming calls.
 The system shall be able to start automatically without human intervention when the
external AC power is resumed after complete power failure i.e. even after the battery are
discharged.
 The system software shall be protected against loss/alteration of memory due to power
failure, unauthorized command or any other faulty conditions.
Operator console:
The operator consoles shall have following features (but not limited to)
 Number of inbound calls, return calls, call in hold, etc.
 Visual display of calling and called stations
 Busy override
 Supervision of the user extensions and trunks
 Call Conferencing
 Call Park / Hold
 Call waiting, call splitting

96. 84
 Serial calling abbreviated dialing
 Routing of calls
 Selective pickup of calls on hold
 It should be possible to automatically switch attendant consoles to specific night mode
based on the time and day of the week.
 Trunk to CO transfer, key pad dialing
Telephone - user features:
 The system should support the Boss/Secretary feature between the digital phones. It
should be possible to implement this feature with the software itself. Boss and secretary
can call each other using single digit keys. There may be more than one secretary for one
Boss.
 The boss should also benefit from the following additional service:
 Direct secretaries call key
 It should be possible for an user to make an external call from other sets via a PIN thus
bypassing the external call-baring category for that set.
The system should have the following basic telephone features (but not limited to):
 Abbreviated dialing
 Automatic DISA, user authentication
 Call forwarding unconditional on busy/no reply to extension, hunting,
 Group voice mail, operator, paging, etc.
 Call pick-up
 Call parking
 Call waiting indication.
 Calling line identification restriction for internal calls
 Controlled private call by Pin code and password
 Do not disturb
 General night service
 Hunting group

97. 85
 Pad locking to prevent the outgoing calls.
 Last number redial
 Priority call
 Priority cut in
 Minimum six party conference
Telephone features in addition to above basic features (but not limited to):
Digital set:
 Adjustable handset volume
 Caller name display
 Distinctive ringing according to hierarchical level
 Fixed function keys
 Duplex hands-free
 Multi-line: multi-appearance and multi-numbers
 Multi-line selective forwarding
 Message waiting indication
 Calling line identification presentation/restriction (CLIP/CLIR)
 Minimum 6 party conference call
 Storage of unanswered calls with date, time, and callback
Analog Set:
 Pulse/Tone sustainable.
 Modular connection plugs for line & handsets.
 Electronic ringer with adjustable volume & melodies ring.
 Flash, Pause, redial, mute function.
 Desktop Model.
 Message Wait Lamp.
 Line Cord – detachable – 2 Meter long.
 Handset – Cord – detachable.
 Termination Box.
 Hook switches endurance.
 With CLI P

98. 86
Call Metering Application:
 A Call accounting application should be implemented in the system.
 The Call billing application shall be windows based call billing software. The
applications should run on any node of the LAN and communicate with the PABX over
Ethernet TCP / IP link.
 System should store all the call records (approx. 1, 00,000 calls) for a minimum period
of one month.
Mobile phone integration:
The system should support advanced mobility solutions in addition to the inbuilt DECT
feature. The system should have parallel ringing facility.
The system shall have centralized network management system based on open
platform with user friendly interface.
Voice messaging system:
a. The system at the Main building should be equipped with voice only offering the best
interactivity with user. The voicemail should be implemented in a centralized fashion
catering to all the users.
b. The hardware and the software of the voicemail should be embedded within the PABX
through interface boards. The specific needs of the present specifications are:
1. 750 voice mails boxes equipped expandable up to 1000.
2. 500 hrs storage (Min)
Voice messaging system should have following features:
 Call answering or call/record answering function with time stamp.
 Customization of an announcement
 Call forwarding to the voice mail
 Message notification via message indicator LED or voice prompts
 Security: Access to voice mail box through a personal code.
 Distribution list: The user should be able to create their personal distribution list
 Message archiving in case of no action.

99. 87
 Multilingual function support
 The proposed messaging system should offer the Unified messaging solution for voice.
It should be possible to integrate voicemails, fax mails and emails in one mail box and
should be accessible from the one single client application like Microsoft outlook or
Lotus notes. Voice Mail system should be of same make as EPABX.
B. BILL OF MATERIALS
Supply, Installation, Testing & Commissioning of ISDN EPABX Systems as per the
specifications and with major items mention below: -
S.NO Description Quantity
A ISDN EPABX System equipped as below:
1 System control redundancy for CPU, memory, power supply with
the gateway connectivity to the guest house PABX having local
survivability features and as per the specifications.
1 Set
2 Analog Extensions (main)
Wired Capacity
Analog extensions –in Guest house PABX
Wired capacity
700
1000
48
100
3 Digital Extensions (main)
Wired Capacity
48
100
4 CO lines (main)
Wired Capacity
CO lines –Guest house
48
100
10
5 Digital ISDN PRI Trunks ( 30 channels) 2
6 BRI Ports 8
7 Operator Console with licensed Windows Operating system PC 2

100. 88
based operator console with printer.
8 24 ports LAN switches with fiber Tran receivers and accessories for
fiber termination
2
Fiber cable (SM) 6 core with required accessories 350
meters
9 Voice Mail System 16 Ports
10 Krone MDF As
required
11 Power Supply
FCBC with SMF batteries for back up for 8 hours and required
cables
1 set
B SYSTEM NETWORKING 1 Lot
1 Hardware and Software to achieve the Q-SIG feature Transparency
2 Call Metering Application
3 Performance Monitoring Application
4 Local Management Application
5 Remote Maintenance
6 Cordless DECT telephony with 10 hand sets& 4 base stations,
required power supply unit and cables
7 All required hardware & software for application of the system &
control as described in specification based on latest technology
8 All required hardware & software for application of the system &
control as described in specification based on latest technology
C SYSTEM FEATURES
1 Inbuilt Auto attendant. VMS with auto attendant
2 Voice Conferences -as per the specifications
6 party conference – Min.20 simultaneously groups
3 VoIP

101. 89
D EPABX in Guest House having gateway connectivity with main
exchange with all features. The Guest house shall have an
independent 100 ports PABX module with provision for a
gateway to the main PABX
1 Set
1 Analog Extension 48 nos
2 CO Lines 10 nos
3 Analog phones 48 nos
4 Power Supply
FCBC with SMF batteries for back up for 8 hours and required
cables
1 set
5 Krone MDF As
required
E System and power supply unit earthing, installation and
Commissioning ( Main & Guest House)
1 Lot
F Interconnecting cable and accessories, heavy duty HDPE
conduit etc. between main exchange and guest house exchange
connectivity ( Approx. distance 350 meters)
1 Lot
G Telephone sets (Digital/Analog/)
Analog Phone 748 Nos
Digital phone 48 Nos
H Other hardware and software required as per the specifications 1 Lot
Table no 3 hardware and software requirements
TELEPHONE SETS:
The bidder must describe the make & model no of telephone sets. (Analog set,
Digital set & Boss-Secretary phone set) to be used with the system. The proposed
solution must support a variety of telephone instruments, requiring no more than
single twisted-pair wiring. Bidder to enclose their recommendations with the
documents.

102. 90
ExchangeEarthing:
The EPABX system & its accessories shall be grounded to a common ground
point to prevent interference from the external & internal sources. Earthing
electrode shall be as per the relevant applicable standard/B.S. 3043 ( latest) for
EPABX MDF/IDF and batteries. The earthing material shall be as per the
applicable IS/Internationally applicable standards. Required earth pits for earthing
shall be made by bidder for EPBAX system, power supply unit and MDF / IDF
.Earthing shall be done as per the ITU recommendation.
MDF/IDF:
SuitableMDF/IDF shall be provided for termination of the extension, trunk lines
The MDF/IDF shall be housed in self-standing/wall type metal frame. The
termination strips shall be disconnection type provided with isolation facility
Suitable protection shall be provided against induced voltages and currents due
to lightning, high voltages line etc. The devices shall provide prompt isolation
and protection from accidental high voltage power contact and safe guard the
equipment against any damage.
Inspection and Testing:
Inspection shall be done as per approved QAP. System shall be tested to confirm
the defined specifications. All routine and acceptance tests shall be conducted on
complete system. Supplier shall submit the QAP for the EPABX system and its
accessories algorithm test certificates and internal test reports before inspection.
Purchaser may ask to conduct type tests; same shall be conducted by supplier
free of cost.
Factory Test: The bidder shall conduct factory test and same shall be witnessed
by CDRI/EPI./their representative In case inspection is waived off, complete
report of all factory test results shall be provided to CDRI/EPI before dispatch.
Site Acceptance: All the system configuration checks/tests to demonstrate the
various components, sub-assemblies of hardware and software shall be carried out
to check/test that system complies with the specification.

103. 91
Approvals
Bidder shall submit all the approval certificates from DOT for the offered model
along with the offer. The statutory clearance and certificate from Govt.
agencies/DOT/TEC for installation and operation shall be arranged by bidder.
Installation and commissioning:
The installation and commissioning of complete system including laying and
termination of cables shall be in the scope of bidder. All routine testing and
operation of the system shall be carried out by the bidder at site. Installation shall
be done as per the applicable relevant standard. All the required commissioning
spares and consumables shall be in the bidder’s scope.
Training:
The vendor shall provide comprehensive training on various operation and
Maintenance aspects of EPABX system to CDRI’s
Representatives/operators (6 personnel’s). The training shall be conducted at
supplier’s works and at site (Bidder to include training charges, if applicable)
Tools & Tackles:
Supply of all the Special tools / tackles like Krone tool, Crimping tool for RJ
Connector, Testing jack, Disconnection plug, Multi-meter shall be in the scope
of the bidder.
Documents and Drawings:
6 sets of following drawings/documents shall be submitted for approval/
reference.
* EPABX System configuration.
* EPABX System description and operational features.
* EPABX System Specifications
* EPBAX System GA drawing
* Valid TEC approval for the make and model quoted. ( system and facility)

104. 92
* List of recommended spares for 3 years of normal operation
* Technical literature/catalogue.
* Calculation for AH capacity of backup power supply and make, model no
and detailed specifications of the power supply and batteries
* Power supply points requirement for main EPABX, Guest House PABX
and other equipment ( Rating and no. of points)
* Total load requirement of EPABX ( Main & Guest House)
 Operation and maintenance manuals for software and hardware.
 List of furniture for main exchange and guest house
 MDF numbering plan / IDF numbering plan.
 Hard copy and soft copy of programming
 Other required Approvals
 MDF/ IDF GA Drawings
 Termination details
 Test reports and certificates
 EPABX System BOQ
 Operating, maintenance and metering software.
 Internal Layout diagram
 Quality assurance plan
 Earthing layout
 Specifications for recommended telephone sets (Analog ,Digital &
boss secretary)
 Power supply requirements and total power consumption.
Note: ‘*’ One set of Drawings/Documents are to be submitted with bid documents.

105. 93
APPENDIX C
TECHNICAL PARTICULARS/COMPLIANCE
TO BE FURNISHED BY THE BIDDER
SECTION – 3

106. 94
SYSTEM FEATURES:
S.No. Description of item/ Statement Compliance
Yes/ No
1 The EPABX shall be fully digital and shall employ Stored
Program Control (SPC) using Pulse Code Modulation
(PCM) and Time Division Multiplexing (TDM), confirming
to latest ITUT (CCITT) standards. ISDN, VoIP
2 The system shall be fully non-blocking with 1 Erlang traffic
for Trunks as well as extensions in fully expanded mode.
3 The CPU of EPABX shall be Pentium (latest version) with
minimum 32 bit microprocessor.
4 The system should have backup memory in the form of
Hard disk (at least 80 GB) with at least1 GB RAM.
5 The exchange shall provide caller line identification on
digital and analog extensions.
6 The System shall be suitable to accommodate both Decadic
Pulse (DP) and DTMF telephones. The system shall also
support DTMF facility.
7 The Exchange shall have minimum traffic handling capacity
of min 250000 Busy Hour Call Attempt (BHCA).
8 The system software shall be protected against loss/
alteration of memory due to power failure, unauthorized
command or any other faulty condition.
9 System shall support 6 party conferences using
Analog/Digital Phones. It should be possible to have 20
(min) simultaneous conferences of 06 parties.
10 The system shall be based on Universal Port Architecture
and shall meet the standard performance limits in respect of
signaling and transmission conditions of Indian
Telecommunication and data networks.
11 System shall have hot standby duplication of each of the

107. 95
following;
CPU of EPABX
Memory
Power Supply in all the shelves
Control cards
On failure of any one of these control section components,
the duplicated section should take over without drop of any
call. Further it shall be possible to make and receive calls
during the switcher period. There should not be any
interruption in the system tone during the changeover.
12 The system shall have Modular Design for expansion/
addition of features as well as hardware.
13 All the peripheral cards (Extension card, Trunk card, ISDN
card etc.) shall be hot swappable. i.e. Replacing a peripheral
card shall be possible without switching off the system.
14 The equipment shall have flexibility to add/delete/modify
Service Features and other facilities without requiring
extensive modification.
15 The maintenance package shall be windows based and it
shall have auto-fault diagnostic facility
16 The system shall be possible to manage and maintain the
system from any Internet Browser and The system shall
have Remote Maintenance with security pass codes.
17 The system shall support voice processing applications such
as voice Mail, auto attendant.
18 In the night mode, when the operator is not present at the
console, the direct lines shall be routed to different
extensions for incoming calls. Once the call lands in the
department, it shall be possible to answer it from any
station.
19 The system shall have dynamic traffic reporting. It should
be possible to integrate Industrial Paging and Radio Paging

108. 96
System with the proposed EPABX.
20 External calls shall select least cost route in a multi service
provider environment. It shall be possible to connect the
system with GSM networks.
21 The system shall have FCBC with sealed maintenance free
batteries so as to give back up of up to 8 hours in case of
power failure.
22 The System shall operate on 230V+-10%, 50Hz+- 5% AC
Input. Through FCBC
23 The system shall have emergency transfer facility to
automatically route the C.O. lines to pre-programmed
extensions in case of power failure.
24 The System shall support remote shelves on IP LAN
switches. Fiber termination shall include the fiber
tranreceivers ,24 port. LAN switches .
25 The system shall work with any type of Public Exchange or
similar network which it shall be connected without
requiring any modification in networks. It shall be possible
to network with exchanges of different makes/ technologies
using either:
IP connectivity
Analog C.O. Lines
Level DID Lines
ISDN BRI lines (2B+D)
ISDN PRI lines (30 B+D)
26 The offered system shall support in homogeneous network
wherein multi-vendor EPABX are networked together. The
EPABX shall be QSIG compliant as per ECMA Forum.
Bidderto attach certificate from any govt bodyin India
certifying the demonstration of QSIG.

109. 97
27 The DECT ( Digital Enhanced Cordless Telephony) based
cordless phones ( with display) should be capable of
functioning as extensions voice terminals of EPABX
.Required hardware & software for DECT telephony with
base stations and connecting cable between system and base
station (Tentatively base station at 4 locations) and hand
sets (10 Nos) shall be supplied.
28 The system shall be suitable for minimum 3 digit
numbering scheme. The extension numbering scheme
should be flexible and it should be possible to do
modification of extension features.
29 System shall support direct LAN connectivity on RJ 45.
The transmission bandwidth shall be 10 Mbps (min).
30 Unified Messaging
The offered system shall support a unified messaging
application. This application should be connected to the
EPABX on SO bus so as to ensure optimum availability and
speed. The UMS shall support voice mail , Email. SMS and
fax mail messaging
31 System shall support Digital Phones on single Pair cable
with Simultaneous Voice & Data capability. The distance
between Digital Phones & System may be 1000. Digital
phones should offer the following min features:
2 line display Display.
12 Programmable Keys
Add on Key Modules
Adap support for ISDN/Analog/Digital
Support for master slave
32 The system shall support CTI applications.
33 System shall support various phone adapters like ISDN
adapter, digital adapter/ analog adapter for connecting

110. 98
additional phones, distance adapter for increasing distance
etc.
34 The system shall support IP phones comply with both SIP
& H.323 standards.
35 Video Communication shall be possible via the offered
EPABX system based on ITU-TS standard H.320
36 System shall support Network Management with the
following facilities:
Configuration Management.
Performance Management
Fault Management
Inventory Management
Directory Services
Call charge Computing
37 IP distribution Architecture
The system shall support the option of distributing
peripheral modules (Shelves) via an IP network. Equipment
shall support remote shelf distributed over IP. All IP points
shall be centrally administrable from the host system.
Distributed switching shall be possible on the IP networks
remote points also.
The voice compression option shall be according to ITU-T
G. 729A. The system shall also support QoS support via the
IP network, IETF diff Service (RFC 2474) IEEE 802.1 d
(incl.802.1p) IEEE 802.1q
The payload channels within or between distributed shelves
shall be switched via the central system.
There shall be no restrictions concerning the system or
subscriber functionality in the distributed architecture.
Subscribers attached to the remote IP shelf shall experience
the full feature set as though they were connected to the

111. 99
central switching location via a traditional TDM bus.
38 Integrated IP Gateway
It shall be possible to connect IP work points to the offered
communication server. The system should provide the same
features for IP work points as for traditionally connected
subscribers.
39 System shall be able to restart automatically without human
intervention when the external AC power supply is resumed
after complete power failure i.e. even after batteries are
discharged.
40. The system shall support IP phones that shall be of the same
make as the make of EPABX.. They shall comply SIPM &
H.323 standards.
41 The system shall support Digital multi key telephones. The
phones hall work on single pair of cable and shall be
powered direcly from the system.
42 Current consumption on full load ( Bidder to specify)
43 System shall support ADSL connectivity for extensions
II. ENGINEERING ASPECTS :
(a) The system shall have processor card, tone card, the facility
card, the line card, junction card and any other card/cards as
may be required for meeting the interest of the requirements.
Exchange offered and with Department of Telecom systems.
(b) All cards shall be of one size and shall be housed in one sub-
rack. The sub-rack shall also house power supply unit and
ringer unit. The sub-rack along with the MDF (Krone type
connectors) shall be housed in a suitable cabinet with Perspex
front panel of sheet steel.

112. 100
I The pin out of the cards shall be standard for identical signals.
Bus bars shall be fixed on to the sub-rack for distribution of
power supply. Inter sub-rack cabling shall be through back
panel patch cables. The attendant console shall be connected
to the exchange through suitable cable of adequate no. of pairs
and required length.
(d) The MDF (with Krone connectors) and necessary fuse
protection to prevent any damage to the exchange system due
to external surges shall be mounted on the sub-track inside the
exchange cabinet and shall contain all terminations. All line
cards shall have line-fuse and high voltage surge-suppressor.
I The power supply unit shall derive input power from AC/DC
converter having 230V +/- 10% single phase 50 Hz +/- 5%AC
input and 48 V DCpower as the output. The power pack unit
shall be backed up by suitable capacity rechargeable storage
batteries to take the exchange load for 8 hours in the case of
mains failure. The power supply unit shall have suitable fully
solid state trickle/boost/float charge system as an integral part.
(f) The sub-rack shall be provided with suitable ventilation
arrangement. The batteries shall be housed in an independent
wooden/steel rack with protection for acid spill over.
(g) The exchange system shall be fully tropicalized and shall be
able to function in the following conditions of
temperature/humidity.
Temperature 5 deg.C to 45 deg.C
Relative humidity 20% to 90% non-condensing
It shall also be able to withstand the normal dust level in a
normal non-air-conditioned office space.

113. 101
DIAGNOSTICS:
The EPABX shall be able to conduct CPU check, RAM check, EPROM
check on power up and on specific initiation at the time of maintenance.
The following additional facilities with major/minor warning shall also
be provided.
Trunk status/trunk down
Processor card scan fail.
Line card scan fail.
Limb reversal on trunk card.
Tone fails.
Gateway/link failure
Wrong key sequence indication on attendant console.
Card level diagnostics feature.
Battery low.

114. 102
GENERAL FEATURES:
Compliance
Extension to extension call
Dial in line (DIL)
Direct outward dialing
Class of service for local/ STD/ISD/restricted STD
Night call of service
Abbreviated dialing for system
Call Transfer
Add on conference ( 6 Parties- any combinations)
Automatic call back on busy trunk
Call consultation
Hunting groups
Do not disturb
Override security
Pre information tone (Warning tone)
Voice mail interface
Operator call
Voice guidance
Group to group restriction
Direct inward dialing
Operator assisted call
Discriminative ring for internal and external calls
Appointment reminder

115. 103
Abbreviated dialing for individual
Call forwarding- Preset, busy, ring
Call pick up & group call pick up
Automatic call back on busy extension/ ringing
extension
Last number redial
Executive override
Flexible programming facility
Direct inward system access through password
Personal Identification Number
Call parking
Hot line
Networking Features
The line accommodation (all types as listed above)
Tie to CO connection
Automatic route selection
Automatic call back
Least cost routing
Tie to Tie connection
C.O. to Tie connection
Alternative route selection
Call forwarding
Add to conference
Digital Networking features

116. 104
Tie line accommodation (all types as listed above)
Tie to CO connection
Automatic Route selection
Automatic call back- busy/ no answer
Centralised call billing
Executive override
Call waiting
Tie to Tie connection
C.O to Tie connection
Alternative route selection
Call forwarding
Add on conference
Centralised administration
Least cost routing
Centralised Voice Mail system
Closed numbering scheme with 3 digit translation
Operator console
PC based (windows based)
Automatic recall
Serial in / out
Interposition calling
Reportory keys
Screened call transfer
Automatic call back on busy Tie/ trunk

117. 105
Night service
Busy override
Calls queuing
Trunk reservation
Un screen call transfer
Number redial
Digital Multi key telephones
Caller name display
Time display
Voice calling
Executive Override
Automatic call back
Call pick up
Caller extension display
Redial
Call log for missed, dialed, received numbers
Function keys for features
Call waiting
Do not disturb
Key telephone features for group
To be furnished by bidders for the two EPABXs

118. 106
1. Make
2. Model Number
3. Capacity
Ultimate
a) Total number of ports
b) Maximum CO lines possible
c) Maximum extensions possible
d) Whether the allocation of ports for
CO lines and extensions flexible
e) No. of ports required for each console
f) No. of consoles that can be connected
Capacity offered
a) Total number of ports
b) Ports for CO lines
c) Ports for extension (Net)
4. Technology
5. Whether 100% non-blocking (indicate the number
of time slots)
6. No. and type of consoles offered.
7. .Whether the extension cords can support message
waiting lamp in case of voice mail facility
8. The number of CO lines each card will support.
9. The number of extensions each card will support.

119. 107
10. FCBC & Standby Power
a) Make
b) Model Number
c) Boost charge rate
d) Trickle charge rate
e) Input volts tolerance
f) Output volts
g) No. of batteries
h) Volts of each battery
i) Amp. Hours rating of battery
j) Back up time (min 8 hours required)
15. Whether Krone type tag blocks for CO lines and
extension lines included.
16. Exchange Software
a) Whether a closed user group facility available.
b) Whether restricted inward dialing facility
available.
17. Voice Mail and Direct Inward Dialling
i) Direct Inward Dialing
a) Whether this will accept dialing from DTMF and
DP type of telephone instruments.
b) Whether pulse tone converter cards included
c) How many ports each card can support.
d) Automatic transfer to operator in case all the
DID ports are busy is available for the incoming
calls.

120. 108
e) In case of the extension being busy, no
response or faulty, whether the call is automatically
directed to the extensions voice mail box.
f) If programmed by the extension, whether the
caller will be directed automatically to the
respective voice mail box.
ii) Voice Mail
No. of ports quoted for voice mail.
b) How many ports will be supported by each card?
c) Whether facility to access mail box from
external line is available.
d) Voice Mail Hardware
(1) Make of PC
(2) Type
(3) RAM
(4) HDD
(5) FDD (size)
(6) Monitor (Type, size, model)
(7) Keyboard (type, make)
e) Uninterrupted Power Supply
(1) Make
(2) Type
(3) Capacity
(4) Battery backup
f) Software (name & version)
g) Size of voice mail box

121. 109
k) What is total time of voice mail recording?
18. Telephone Instruments
a) Analog Type (750 Nos.)
Make
Model
b) Digital type (50 Nos)
Make
Model
c) DECT type (10 Nos.)
Make
Model

122. 110
APPENDIX D
LIST OF RECOMMENDED
VENDORS
SECTION – 4

123. 111
LIST OF RECOMMENDED VENDORS:
S. No. Items Approved Makes
1. ANALOG PHONE ALCATEL/SIEMENS/NORTEL/AVAYA/BEE
TEL
2 DIGITAL PHONE ALCATEL/SIEMENS/NORTEL/AVAYA/
ERICSSION.
3 PC BASED OPERATOR CONSOLE ALCATEL/SIEMENS/NORTEL/AVAYA/ERIC
SSION.
4 FCBC HBLPOWER/AMARARAJA/STATCON
/DYNA
5 BATTERIES EXIDE/ HBL POWER/ GLOBAL
YOUASA/AMARARAJA
6 MDF/IDF, TAG BLOCKs KRONE
7 PC HP/HCL/IBM/DEL/COMPAQ
8 PRINTER EPSON,HP, TVSE
9 TELEPHONE WIRES/ DATA
CABLE
DELTON/.FINOLEX/SKYTONE/HAVELL’S
LAPP/BELDEN/SYSTIMAX/AMP
10 24 PORTS LAYER SWITCH CISCO/NORTEL

124. 112
APPENDIX E
LIST OF DRAWINGS
SECTION – 5

125. 113
List of Drawings
EPABX SYSTEM
S.No. Drawing No. Title
1. CDRI/LKW/499/E1-W-714
REV.04
EXTERNAL TELEPHONE CABLE
LAYOUT
2. CDRI/LKW/499/E1-W-712
REV.02
BLOCK DIAGRAM FOR TELEPHONE
DISTRIBUTION SYSTEM

126. 114
BIBLIOGRAPHY
TEXT BOOKS REFERED:
1. “TELECOMMUNICATION SWITCHING SYSTEMS AND NETWORKS” by
ThiagarajanViswanathan: PHI Publication.
2. “WIRELESS COMMUNICATIONS: PRINCIPLES AND PRACTICE” by
Rappaport: Pearson Education India.
WEBSITES VIEWED:
1. www.wikipedia.com
2. www.dallassemiconductors.com
3. www.maxim-ic.com