The document provides an overview of Private Automatic Branch Exchange (PABX) systems, particularly focusing on Avaya IP Office technology and its evolution in Bangladesh's telecommunication landscape. It explains the functionality of PABX, which enables efficient call routing and management in large organizations, and outlines specific components of the Avaya IP Office system, including various modules and devices for improved VoIP communication. Key features include its support for both analog and IP phones, essential for modern telephony services.

1. PRIVATE AUTOMATIC BRANCH
EXCHANGE
UNDERSTANDING PABX & AVAYA IPOFFICE ON EYE OF AN IT GUY
Shahriar Kabir
IP Telephony

2. TELEPHONY SERVICE EVOLUTION IN BANGLADESH
1972
• Analog
Telephony
Systems
1994
• Digital
Telephony
Systems
1996
• Mobile
Telephony
Systems
2009
• IP
Telephony
Systems

3. PRIVATE AUTOMATIC BRANCH
EXCHANGE (PABX)
Private automatic branch exchange (PABX) is a technology
used by call centers and other large organizations to
designed to share lines and route calls.
Allows a single access number to provide several lines to
outside callers while providing a range of external lines to
internal callers or staff.
PABX performs all the switching necessary for making
internal calls between extensions within the organizations. It
also allows provides a connection between extensions and
external lines.
PABX is the improved version of the private branch exchange
(PBX).

4. WHY PRIVATE, AUTOMATIC?
The exchange is owned and managed by the
private organization/ body in which it is installed
and relies on computer equipment to handle the
switching of calls.
This is why the system is considered both private
and automatic.

5. Wireless User Brand/Proprietary
Expansion SwitchEthernet Switch
Router
Internet Operator
Media Converter
Another Operator
Legacy Device
Analog Expansion Module
IP PABX as
(Call) Router
/ Call Server
Generic ComputerGeneric SIP Phone
Analog Trunk Module
Telephony Operator
BASIC STRUCTURE OF
(IP) PRIVATE NETWORK
BASIC STRUCTURE OF
(IP) PRIVATE BRANCH EXCHANGE

6. Wireless User Brand/Proprietar
y
Ethernet Switch
Another
Operator
Legacy
Device
Analog Expansion
Module
IP PABX as
(Call) Router
/ Call Server
Generic SIP Phone
Analog Trunk
Module
Telephony Operator
Another
Operator
International
Gateway
Interconnection Exchange
Direct Media Path
BASIC OPERATION OF
(IP) PABX

7. Wireless User Brand/Proprietary
Ethernet Switch
Router Another Operator
Legacy Device
Analog Expansion Module
IP PABX as
(Call) Router
/ Call Server
Generic SIP Phone
Analog Trunk Module
Telephony Operator
BASIC STRUCTURE OF
(IP) PABX

8. AVAYA IP OFFICE

9. AVAYA IP OFFICE-
CONTROLLER UNIT (CU)

10. AVAYA IP OFFICE- VOICE
COMPRESSION MODULES (VCM)
Enables use of IP phones on IP
Office system.
Used for VoIP calls, IP
networking and SIP trunks.
The actual number of channels
provided is controlled by the
VCM Channels licenses within IP
Office.

11. AVAYA IP OFFICE- ANALOG PHONE8
CARD
Provide POT ports for analog
telephones.
The IP Office Analog Phone Card
is available in 2 versions
providing 2 or 8 extensions.
Telephones can be located up to
1 km from the unit using CAT5
cabling

12. AVAYA IP OFFICE- ANALOG TRUNK
MODULE (ATM) CARD
Four analog trunk ports (9-12)
via a pre-installed IP500 Analog
Trunk 4 daughter card.

13. AVAYA IP OFFICE-
CONTROLLER UNIT (CU)

14. AVAYA IP OFFICE- ANALOG PHONE
(EXPANSION) MODULE
The Phone module is available in 2 versions providing 16
or 30 extensions.
16 Module and 30 Module provide POT ports for analog
telephones.
Telephones can be located up to 1 km from the unit using
CAT5 cabling

15. AVAYA IP OFFICE- ANALOG TRUNK
(EXPANSION) MODULE
Analog Trunk 16 and Analog Trunk 8 Module provides an
additional sixteen LS/GS two-wire analog trunks.

16. AVAYA IP OFFICE- ADDITIONAL SERVICE
NODES

17. AVAYA IP OFFICE- AUTO ATTENDANT

18. Wireless User Brand/Proprietary
Ethernet Switch
Router Another Operator
Legacy Device
Analog Expansion Module
IP PABX as
(Call) Router
/ Call Server
Generic SIP Phone
Analog Trunk Module
Telephony Operator
BASIC STRUCTURE OF
(IP) PABX

19. USER DEVICE: IP PHONE-
H.323

20. USER DEVICE: IP PHONE- SIP

21. USER DEVICE: ANALOG
PHONE

22. USER DEVICE: SIP DIALER

23. THANK YOU
FOCUSED ON
BASIC PABX CONCEPT
• CONCEPT
• WORKING PRINCIPLE
&
AVAYA IP OFFICE
• SERVER COMPONENTS
• STRUCTURAL DESIGN
• WORKING PRINCIPLE
• CLIENT DEVICES