Migration of C-DOT MAX to C-DOT MAX-NG ----- An Overview

1. Migration of C-DOT MAX to C-DOT MAX-NG ----- An Overview

2. Overview of VoIP

3. What is VoIP ? • Why VoIP ? • What is NGN ? • Circuit Switching vs. VoIP • Benefits of VoIP over TDM • Protocols

4. Exchange Exchange Switch Switch Router Router Evolution of Telephony Local Loop Trunk Local Loop AnalogTelephony Access TAX Access Digital Telephony Access Core Access Packet Telephony (e.g. VoIP)

5. What is VoIP ? • IP used to deliver digitized voice(or similar time critical interactive services) over a managed/unmanaged network. (Local Area Network, Wide Area Network, Internet) Internet Telephony • Time critical voice over unmanaged public internet • PC to PC using Skype or Gtalk

6. Why VoIP ? • Reducing Infrastructure cost. • Provide multiple services on unique IP broadband connection. • Reducing ROI time • Increase convergence capabilities and Value-Added Services • Dramatically improves efficiency of bandwidth use for real-time voice transmission

7. What is NGN? ITU definition • A packet-based network able to provide telecommunication services and able to make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies • A multi-service Network able to support Voice, Data and Video. • A Network with a control plane (Signaling, Control) separated from the Transport/Switching plane. • A Network with open interfaces between transport, control and applications. • A Network using packet mode technology to transport of all kind of information.

8. Journey to NGN • Digitization had changed the complexion of telecom and IT • Different networks were made to carry information in digital format. • Individual service specific networks are developing into IP based networks. • Possibility to offer different services of voice, data, video on same service specific platform. • Possibility of offering new innovative services to the subscribers • NGN is IP based platform to offer every thing on IP Thus Migration towards the NGN appears to be inevitable

9. TDM and VoIP ArchitectureDifferences • In case of VoIP, Call processing & Control Logic and transmission are two separate entities. The two layers work through a protocol. • In the traditional switch the same is inter-mingled with other . • Hence switching control in the soft switch becomes independent of the type of traffic. Fixed, voice , mobile data, multimedia, any legacy

10. Different Components of NGN • Gateways • MG (Media Gateway) • SG (Signaling Gateways) • LAG/LMG (Line Access/Media Gateways) • V5AG (V5.2 Access Gateways) • PRIAG (PRI Access Gateways) • SS (Soft Switch) • Class 4 SS • Class 5 SS • APS (Application Server/Feature Server) • PRBT (Personalized Ring Back Tone Server) • BS (Billing Server) • iEMS (Integrated Element Management Server)

12. GATEWAYS

13. Media Gateway • The media gateway provides a means to transport voice, data, fax, and video media between the IP packet network and the PSTN network. • It provide interworking of voice connection between PSTN and IP.

14. Signaling Gateway • A Signaling Gateway creates a bridge between the SS7 network and an IP network, under the control of the Media Gateway Controller.

15. Analog Gateways(IAD/ATA/LMG/LAG) • Interface between the legacy telephones (POTS), fax machine to the IP network via SIP. • Support Analog Devices.

16. V5.2 Access Gateway • Interfaces between the V5.2 access network and the IP network via SIP.

17. PRI Gateway • Interface of Primary Rate Interface (30B +D) to the IP network via SIP over IP • The customer interface is transparent to the core network

18. SS (Soft Switch)

19. Softswitch • Softswitch is also known as Media Gateway Controller, (MGC), Call Server (CS) or Call Agent (CA). The Softswitch is located in the service provider’s network and handles call control and signaling functions, typically maintaining call state for every call in the network. A Softswitch interacts with Application Servers to provide services that are not directly hosted on Softswitch. • Softswitch is used for local/transit or local cum transit application which is deployed in the control layer of NGN (Next Generation Network), in a network architecture employing standards NGN protocol as per international standards and IP based packet transport.

20. The Softswitch shall provide interoperability with all types of network elements in the present Switched Circuit Network (SCN). The Softswitch shall interface with existing SCN switches through Trunk Media Gateways, Line Media Gateways, and Signaling Gateways etc. The Softswitch shall use fault-tolerant, highly scalable and open-ended state-of-the-art hardware, software & networking technologies; and provide carrier-grade performance, to comply with the reliability and service quality standards specified in this document. • VoIP Softswitches are subdivided into two classes. Class 4 softswitches and Class 5 softswitches. • Softswitches used for transit VoIP traffic between carriers are usually called class 4 softswitches. Analogous with other Class 4 telephone switches, the main function of the class 4 softswitch is the routing of large volumes of long distance VoIP calls. The most important characteristics of class 4 softswitch are protocol support and conversion, transcoding, calls per second rate, average time of one call routing, number of concurrent calls. • Class 5 softswitches are intended for work with end-users. These softswitches are both for local and long distance telephony services. Class 5 softswitches are characterized by additional services for end-users and corporate clients such as IP PBX features, call center services, calling card platform, types of authorization, and other features similar to other Class 5 telephone switches.

21. Application Server

22. Application Server An application server can be either a software framework that provides a generalized approach to creating an application-server implementation, without regard to what application functions are, or the server portion of a specific implementation instance. In either case, the server's function is dedicated to the efficient execution of procedures (programs, routines, scripts) for supporting its applied applications. Likes • PRBT (Personalized Ring Back Tone Server) • BS (Billing Server) • iEMS (Integrated Element Management Server)

23. Limitations in existing C-DoT Systems- Challenges with BSNL As per C-DoT, the existing DSS technology is computer driven, a key component in the entire system is the memory, which is limited and shall be obsolete in near future. Unable to meet the demands for new features, services or modifications due to its limited memory. Non availability of maintenance spares like controller cards – Big challenge – (BSNL repairs centers are only equipped for repair of Line cards)

24. Why MAX-NG ? • Less Infrastructure cost in upgradation • Centralized control • Different business model of IP • Ease in up gradation • Remote support • Component obsolescence

25. The main advantages with such migration • The legacy equipment can be migrated to IP in much lower cost • than the cost of its replacement with new IP equipment. • Complete benefit of a converged multimedia core network from day one of migration. • New hardware is directly reusable in all IP networks, leading complete protection in migration investments as compared to replacement by new Line Media gateways. • Line Termination Units and Customer premises equipment remains unchanged at subscriber side for voice only subscribers

26. C-DOT DSS migration plan – Objectives in mind • Migration of existing MAX/AN-RAX systems to VoIP based next generation network. • Independence from proprietary hardware obsolescence in future to the maximum extent possible • Enhanced call handling capacity in the NGN network • Centralize creation and introduction of new services and also Improved monitoring of services • Faster time-to-delivery for new features and services. • Achieve flexible expansion. • Improved response times to BSNL’s requests for changes • Quicker propagation of software changes to field deployed systems • Protection of investment and minimal additional investment.

27. Benefits to BSNL • All call switching is moved to central soft-switches executing on off-the-shelf server technology.- No proprietary interfaces are required. • Use of standard protocols permits easy integration of upgraded components into a multi-vendor IP network. • Single card solution, which is software configurable to suit various functionalities like Line access Gateway, Signaling Gateways and PRI/V5.2 & Trunk Media Gateways etc. • Concurrent support for multiple legacy protocols like SS&,PRI, V5.2, POTS from on common hardware. • New Services can be created by third parties. • New services can be introduced simultaneously in all parts of the network from a single point. • Management and control interfaces are web based and accessible from any point in the network to authorized users. • Easy integration with other IP and legacy elements in the network • IVRS and web self-care portals provided to subscribers for selecting and configuring service features. • Integration of traditional SCP based IN services for all types of subscribers (Fixed, Mobile, PSTN, IP etc.)

33. Status of the Project • The C-DOT MAX-NG Field Trail was started in the month of Jan-Feb’2010 initially at Nuh, Gurgaon. • The first IP live call was put through in Feb 2010 Achieved Stability • The system got stabilized somewhere in April-May 2010, after resolving various operational and field problems observed at Nuh. • Subsequently, the other two sites namely Katpadi, Vellore SSA and Vikanagar, Dehradun SSA was upgraded to C-DOT MAX NG successfully.

34. Status of the Project (Cont.) • All the three sites are live and the backbone is IP/MPLS presently. • There were many issues / problems initially, which were resolved by C-DOT during the field trials. However few issues likes echo problem, traffic reports, single window provisioning (IEMS) and Sig. link problem etc are in final phase of validation. • The CDR data pulling from all sites have successfully completed in the month of Feb’2011.

35. Status of the Project (Cont.) • After successful filed trails at all the three local sites, the validation of C-DOT MAX- NG was stared in the following manner in Feb 2011: • Subscriber Management, features etc. at Vellore-PHASE-I • ISDN/V5.2 Gateways etc. at Dehradun – PHASE-II • Soft Switch & other core equipments at Delhi/Gurgaon-PHASE-III • A Validation Committee was formed with members from T&D, QA, the three field trial sites, ITPC officers.

36. Few activities are being validated like IOT with IP-TAX/SCP, DR/GR functionality between Softswitches installed at Gurgaon & Nodia, Lawful Interception test as per TEC- GR etc.

37. SYSTEM CONFIGURATION DETAIL OF MAX-NG TRIAL SITES

38. SYSTEM CONFIGURATION

39. Existing MAX/RAX Architecture Signaling Gateway Function Trunk Unit SS7 Unit Service Control Point Access Gateway Function Media Gateway Function Call Processing & Service Switching Point (SSP) Message Switch Terminal Unit Features & Media Services Voice Path • Broadband Access Unit • ADSL2+ • WiMax • Broadband Access Unit • ADSL2+ • WiMax • Broadband Access Unit • ADSL2+ • WiMax Time Switch ILT class 4+5 Softswitch Class 5 Triple Play Softswitch IP Routing Function Service Circuits & Interface Terminal Unit Control Path The Broadband Access Units replace PSTN Terminal Units + Gateway functions for completing migration to all-IP network Call Processing Logic externalized to a combined Class4 and Class5 softswitch Trunk unit upgraded with media gateway function & controlled by Class 4 softswitch Access gateway controlled by the external Class 5 softswitch ADSL2+ or Wimax based Broadband Access Units can be additionally added Voice path and control path switching merged, replaced with IP router function Terminal Units form part of Access Gateway functionality Subscriber line termination unit retained, all other units VoIP enabled SS7 unit upgraded with signaling gateway function, interworks with Class 4 softswitch Media processing and call feature handling externalized to Media/Application servers VoIP Upgraded Portion Retained Portion

40. Softswitch IP Network Line Cards LMG Copy 0 Copy 1 Switch & Control Cards Copy 0 Copy 1 Copy 0 Copy 0 Copy 0 Copy 1 Copy 1 Copy 1 Broadband Unit Copy 0 Copy 0 Copy 1 Copy 1 Copy 0 Copy 0 Copy 0 Copy 1 Copy 1 Copy 1 Copy 0 Copy 1 Copy 0 Copy 1 Copy 0 Copy 0 Copy 1 Copy 1 Upgrading the MAX/RAX Copy 0 Copy 1 Central Module Copy 0 Copy 1 Base Modules Line Media Gateway Base Module

41. Architecture of Core / Access

43. Existing Line Termination Units Existing Line Termination Units

44. Setup at MAX-NG Field Trial sites