This document provides an overview of CDOT's MAX NG system and the migration from the existing MAX system. The key points are: 1. MAX NG features a distributed architecture with centralized control and uses software to provide enhanced services like video calling. This reduces infrastructure costs and makes upgrades simpler. 2. Migrating the MAX system involves converting line and trunk interfaces to VoIP gateways, moving switching functions to an external softswitch, and replacing internal media paths with IP. 3. The MAX NG architecture consists of a core network for service delivery and an access network of upgraded MAX exchanges. The core uses softswitches and other servers while the access uses Line Access Gateway Units and a Central Access

1. CDOT MAX NG

2. Agenda
Introduction to CDOT DSS Family
Implementation of MAX NG
Need for MAX NG
Changes in CDOT for migrating to MAX NG

3. INTRODUCTION
 C-DOT DSS MAX can be configured as
• local,
• transit,
– or integrated local and transit switch.
 High traffic/load handling capacity up to 8,00,000
BHCA with termination capacity of 40,000 Lines as
Local Exchange or 15,000 trunks as Trunk Automatic
Exchange.

4. BASIC GROWTH/BUILDING MODULES
• Four basic modules
 Base Module
 Central Module
 Administrative Module
 Input Output Module

5. Base Module
 BM is the basic growth unit of the system.
 The interfaces may be subscriber lines, analog and digital trunks,
CCM and PBX lines.
 Each Base Module can interface up to 2024 terminations.
 It carries out majority of call processing functions and, in a small-
exchange application, it also carries out operation and
maintenance functions with the help of the Input Output Module.
 As SBM it act as individual switch and provide 1500 lines and 128
trunks.

6. Central Module
 It consists of message and space switch to
provide inter module communication and
perform voice and data switching between
modules.
 It provides clock and synchronization.

7. Administrative Module
 System level resource allocation and
processing function.
 Administration and maintenance functions.
 Supports ADP

8. Input Output Module
 Input Output Module consists of duplicated
input output processor.
 IOP is general purpose computer with UNIX OS
 IOP is connected to AP/BP via HDLC links.

9. Remote Switch Unit (RSU)
 RSU is connected to host exchange via 2Mbps link.
 A maximum of 16 PCMs can be provided between
RSU and host exchange.
 Standalone mode of operation is possible.
 Only even numbered BMs can be configured as RSU
 Max 16 RSU in MAX-XL
 Max 8 RSU in MAX-L

10. Questions
1. Which is the first electronic switch in India?
A. EWSD B. CDOT C. OCB D. E10B
2. Traffic/ load handling capacity of CDOT is up to
A. 80000 B. 800000 C. 850000 D. None
3. India’s first indigenously developed switch
A. OCB B. E10B C. 5ESS D. CDOT
4. CDOT is a__________ type of switch
A. t-s-s-s-t B. t-s-t C. t-s-s-t
5. Cards used in CDOT for line termination
A. LCC B. CCM C. TSI D. both A& B

11. SYSTEM FEATURES
• General Features
 MAX – larger capacities of order of 2000 lines or beyond
 RAX – expandable up to 2000 lines.
•Types of application
 Replacements
 New exchanges
 Extensions
•Types of system
 Stored programme controlled (SPC)

12. WHY MAX-NG
 Less Infrastructure cost in installation & expansion
 Better enhanced services such as Video calling,
Centrex, Multilingual announcements etc.
 Distributed architecture & Centralized Control
 More calls with less bandwidth
 Involves more of software, simplified hardware
infrastructure and changing upgrade economics, hence
ease in upgradation
 Taking care of Component obsolescence

13. DSS MAX UPGRADE PROCEDURE
 Retain and convert line termination units to VoIP Access
Gateways(LAG)
 Convert trunk interfaces to VoIP Trunk Media Gateways(MG)
 Convert the SS7 unit to a Signalling Gateway with STP
functionality(SG)
 Retain the Integrated Local and Tandem (ILT) functionality by
moving Class 4 and Class 5 switching functions to an external
softswitch (C4/C5)
 Replace internal media and control paths with IP-enabled routing
 Add on broadband interfaces for copper and wireless access.

14. MAX-NG COMPONENT
CORE COMPONENT
ACCESS COMPONENT

15. MAX-NG COMPONENT
 NGN Core Network for delivery of Services
 NGN Access Network consisting of MAX exchanges
upgraded to MAXNG exchanges
 Operations Support Network consisting of
 MAX-NG Billing System Interface
 MAX-NG Service Provisioning Interface
 MAX-NG Network Management
 The existing IP/MPLS based NIB/NIB-II Transport Network

16. MAX-NG ARCHITECTURE
CACU
AN-RAX
PBX
ATU
ATU
ATU
ATU
LAG
U
ATU
ATU
ATU
ATU
LAG
U
ATU
ATU
ATU
ATU
LA
GU
ATU
ATU
ATU
ATU

17. Component of Core
• The core network consists mainly of following servers.
 C5 Softswitch
 C4 Softswitch
 Session Border controller (SBC)
 Rating Engine
 SG Server (Signalling gateway)
 EMS Server (Element Management System)
 LIS Server (Lawful Interception System)

18. C5 Softswitch
• A central device in a telecommunications network which
connects telephone calls from one phone line to another,
entirely by means of software running on a server. SIP
protocol is used to establish calls . Currently in MAX N/W
switching is carried out by hardware, with physical
switchboards to route the calls.
 Soft switch –
 Class 5 SS – Call Agent, Caller Server.
 Class 4 SS – Media Gateway Controller

19. C4 Softswitch
• Class 4 soft switch is used to deliver calls of MAX-NG
subscribers to PLMN/PSTN network via Signalling and
Media Gateway and vice-versa.
• MGC perform call control and signalling routing for
PSTN and Signalling System 7 (SS7) voice traffic.
• MGC uses a Signalling Gateway (SG) to get SS7
signalling over IP, and provides ISUP to SIP and back
translation.
• MGC controls Media Gateway (MG) using
MEGACO/H.248 to translate the voice/media call
component from TDM to RTP and back

20. Session Border Controller (SBC)
• A Session Border Controller (SBC) is a network
function which secures voice over IP (VoIP)
infrastructures while providing interworking
between incompatible signalling messages
and media flows (sessions) from end devices
or application servers. Along with processing
signalling messages,
• Session Border Controllers also handle all
media traffic, typically in the form of RTP.

21. Rating Engine
• The Rating engine is a system used to determine the
customer chargeable units based on:
 Type of the day
 Time of day
 Call duration

22. Other Core Components
• SG Server
• A Signalling Gateway is a network component solely responsible for
translating signalling messages between one medium (usually IP)
and another (PSTN) .
• EMS Server
• EMS (Element Management System) is a GUI based solution for
configuring and monitoring the different systems installed as MAX-
NG components.
• LIS Server (Lawful Interception System)
 Monitoring the calls of a particular subscriber.
 The calls are diverted to another number as configured

23. MAX to MAX NG

24. Line Access Gateway Unit(LAGU)
 C-DOT LAGU is designed to migrate fixed line TDM based
technology of DSS-MAX to IP based technology.
 It converts basic voice into RTP and Signalling information
to SIP and connects to the IP network.
 LAGU provides gateway functionality through a pair of
network gateway cards working in active-standby mode.
 LAGU systems are installed at all co-located and remote
Base Modules of the MAX exchanges.

25. continued…
 A BM system is converted to LAGU system replacing BPU
and TSU with NGTJ cards and TSI cards.
 All TUs with PSUs, TCs (LCC), TIC, SPC and TUI cards are
retained.
 2-slot chassis consists of NGTJ card and TSI card interfacing
with TUI cards in ATU frame.
 Supports maximum 32 E1s from RBM site to co-located BM
site.

26. LAGU Chassis

27. LAGU chassis
LAGU chassis contains two NGTJ & two TSI cards.
TSI cards interface with TUI cards in ATUs through
TT cables.
NGTK variants are NGTK-A00 (EEB integrated) and
NGTK-B00 (EEB not integrated).
LAGU Chassis operates at -48V DC.
5VDC & 12 VDC for LAGU is fed from ATU.

28. Central Access Control Unit(CACU)
• The 6-slot MAX-NG Card Frame (CACU) variant consists of the
following components:
 Four Universal slots
 Pair of redundant aggregation slots
 Pair of redundant Shelf Management and Controller slots
 Pair of redundant -48V power feeds
 A FAN tray at the bottom
 Temperature sensor card with digital temp sensing for each slot

29. CARDS IN CACU CHASSIS
 Shelf Manager (SLM) cards
 NGTK cards
 EBM cards
 MLS cards
 TSN cards

30. CACU Chassis

31. Conclusion
• Cost effective and easy to migrate
• Uses existing infrastructure
• Reduced Migration time

32. Thank you