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Things Change!

Converging Telco and Internet Standards Peter Darling Manager, International & NGN, Australian Communications Industry Forum. Things Change!. Ten years ago The Public Switched Telephone Network (PSTN) was just completing the transition to digital The Internet was starting to move from academia

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Things Change!

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  1. Converging Telco and Internet StandardsPeter DarlingManager, International & NGN,Australian Communications Industry Forum

  2. Things Change! • Ten years ago • The Public Switched Telephone Network (PSTN) was just completing the transition to digital • The Internet was starting to move from academia • Three years ago • Dot.com mania ruled • It was “reliably” forecast that the Internet was about to take over as the sole communications medium • Today • There is a strike of capital, but • convergence is becoming a reality

  3. In the Future • Telephony and multi-media may be just another application over the Internet, but • There will need to be changes to support user requirements, based current expectations. • To make this happen, there needs to be • Substantial resource investment, and • Substantial standards work • Much current telco standards work directly relates to NGN (next generation networks)

  4. Network Generations

  5. PSTN 2G Mobile • The PSTN/ISDN is based on 64 kbit/s digital connections, with a separate “common channel” signalling system • Access may be analogue (telephony), 64 kbit/s digital (ISDN) or low speed digital (mobiles) • The network establishes an end-to-end digital connection for the duration of each call • The PSTN/ISDN is designed for high reliability, specified at the national level andconnecting to form a global network,

  6. ISP “The Internet” (best-endeavours network) ISP • The (public) Internet is based on the set of protocols defined by the Internet Engineering Task Force (IETF) • The primary protocol is the Internet Protocol (IP) which describes a simple connectionless packet protocol able to operate over a range of media • Other protocols work in association with the IP, for example, TCP to assist reliable end-to-end operation • The Internet is defined by the Internet protocols rather than by a standardised architecture • The Internet provides open interfaces, supporting rapid innovation

  7. Telco Networks 64 kbit/s circuit switching Well defined architecture, fixed and mobile. Designed for high reliability and QoS Specified at national level growing to global Main area for national regulation Dumb terminal, smart network Current Internet Packet switching over diverse media Defined by protocols rather than architecture (TCP/IP) Specified at global level Best endeavours network – no QoS guarantee Open interfaces support rapid innovation Smart terminal, dumb network Next Generation Networks • Largely Packet based (IP & ATM), with necessary extensions to give • a level of service equal to or better than current carrier networks

  8. Network Evolution • There are different paths (not mutually exclusive) by which “an NGN” could evolve: • Interconnection of enterprise IP VPNs • IP expansion of existing carrier networks • New IP-based networks providing integrated service • Addition of QoS support to the existing public Internet • What is the underlying demand, the business case and the likely timing? (The economics of adding QoS to the existing Internet do not seem compelling.)

  9. Quality of Service Provision • Future networks need to provide adequate Quality of Service to support real-time interactive services (e.g. voice) • There has been extensive work on “adding” QoS to the Internet • Implementation of QoS can be • standards driven (primarily IETF work), • based on proprietary approaches • provided by traffic segregation and traffic engineering (over-provision of underlying resources) • Almost all work in the IETF has been directed with a single network rather than across networks (NNI or inter-domain)

  10. Domain 3 Domain 1 Service Domain Service network Client Domain 2 Client Relevant interfaces Transport Network Transport Network Carrier Networks are not homogeneous • Carrier networks consist of multiple domains • each domain may have its own policies • each domain may have its own commercial goals • and possibly its ownprotocols & transport Source: ITU-T SG 11

  11. Why Change? The current circuit switched PSTN provides good service. What are the likely drivers for change to a packet-based network? • Flexibility • The PSTN is based on carrying 64 kbit/s circuits. • Services at bit-rates below this can be carried (but not efficiently) • Services at bit-rates above this can only be carried by combining 64 kbit/s circuits • Open interfaces supporting innovation • Economics

  12. PSTN ISP 2G Mobile “Carrier Grade” IP-based Networks ISP “The Internet” (best-endeavours network) ISP

  13. What is Needed for “Carrier Grade IP”? • The current Internet • Does not provide differentiated quality connections • Queues packets at peak times for maximum efficiency • If the Internet is not congested, real-time (e.g. voice) packets can be delivered, but if there is congestion, real-time services cannot be supported reliably. • There is a need for connection-oriented support to provide a required level of QoS for the duration of a connection (or, in telco terms, a call)

  14. To provide QoS….. • An underlying backbone transport is required (for example, by SONET/SDH over optical fibre or radio) • Backbone resource control protocols such as GMPLS with RSVP-TE or CR-LDP can be used to provide support for resource allocation Backbone transport

  15. To provide QoS….. • It is then necessary to establish specific support for end-to-end connections for the duration of the connection/call. • This can be provided by MPLS enabled routers, or by the use of the virtual circuit capabilities of ATM Bearer Control Backbone transport

  16. To provide QoS….. Call Control • Per call (or session) call control is needed for the duration of each call, to set up, supervise and clear-down. • Possible protocols include • BICC (from the ITU-T) • SIP (from the IETF) • H.323 (from the ITU) Bearer Control Backbone transport

  17. To provide QoS….. Service/application Call Control • SIP and H.323 are end-to-end protocols • An alternative approach is to use centralised control from a Media Gateway Controller / Softswitch, combining bearer and call control • Megaco/MGCP H.248 has been developed by IETF and ITU Bearer Control Backbone transport

  18. QoS Support • Caller must specify requirements • Access network and subsequent networks must provide the required QoS for the duration of the call Current Internet protocols can support this within one network, but not across different networks

  19. PSTN ISP 2G Mobile “Carrier Grade” IP-based Networks ISP ? ? ISP “The Internet” (best-endeavours network) ISP

  20. End-to-End Connectivity? There is no shortage of possible approaches – and they are all in use! The problem • How to guarantee end-to-end service with the required QoS across multiple networks using incompatible implementations[the subject of current international work]

  21. PSTN/ISDN Frame Relay Networks IWF IWF IWF IWF IWF IWF IWF IWF IWF ATM Networks Wireless Access Today’s Network Architectures IP/MPLS Networks Radio Access Networks Ethernet Networks Source: ITU-T SG 13 • Multiple, interworked, interdependent networks • Diversity of control and management architectures • Capacity and performance bottlenecks • Each network has its own control plane and management plane

  22. Wireless access PSTN/ISDN PSTN/ISDN IWF IWF IWF IWF IWF Near Term Evolution SS7 Network Q & X series Rec. Rec. Q.931 Frame Relay Networks Rec. Q.700 series Rec. I.580 Rec. Q.2931, PNNI FR OSF & NM Rec. I.555 Rec. I.580 PSTN/ISDN OSF & NM, M series Rec. IETF RFCs ATM Networks IP-based Networks Rec. Y.1310 ATM OSF & NM, M series Rec. SNMP based • For • Convergence on ATM core networking enables initial stage of unified management and control • Enhanced performance and QoS capabilities for multi-services over common platform • Against • Lack of service transparency between IP based services and ATM/PSTN services OSF = Operating Support Function Source: ITU-T SG 13

  23. IWF IWF IWF IWF IWF IWF Medium-term - Convergence on MPLS Core ATM Networks Frame Relay Networks MPLS NETWORK Frame Relay Networks Ethernet Networks Ethernet Networks ATM Networks Label Switching Router (LSR) Label Switched Path (LSP) • Requires well defined interworking mechanism for all services • Transfer plane functions • Control plane functions • Management plane functions Source: ITU-T SG 13

  24. Inter-Network Resources • Successful solutions have to combine • End to end operation control • Inter-domain resource negotiation

  25. Inter-network Negotiation Alternative approaches include • Requiring each network to support a limited range of QoS/network services (inflexible and prescriptive) • Network by network negotiation (but how to ensure required service is available?)

  26. Ongoing Work • International and national work is need to introduce interoperable next generation networks. Areas requiring work include • Architecture and Protocols • End to end QoS • Service platforms • Network management • Lawful interception • Security • This work is being carried out in the IETF, the ITU and regional telco standards bodies such as ETSI

  27. Ongoing Work • Given the proposed use of Internet Protocols, much current IETF work is directly relevant • Work is needed to define inter-network (inter-domain) interconnection and operation • The following slides summarise some of the current work at the international level. Other bodies working on NGN include fora and consortia such as the Multi-service Switching Forum and the MPLS Forum.

  28. International Work - IETF • RTP (Real Time Protocol) • Carries VoIP audio media • Used by H.323, SIP, Megaco/H.248, others. • SDP (Session Description Protocol) • Describes multimedia sessions • Used widely as well, see above. • SIP (Session Initiation Protocol) • Rendezvous protocol, discovery and session management • Commonly used as VoIP signalling protocol • Associated with MMUSIC, SIP, SIPPING, SIMPLE WGs

  29. International Work - IETF • ENUM (E.164 Number Mapping) • Transforms E.164 telephone numbers into URLs • used for SIP, HTTP, SMTP, etc. • Interim operation plan for e164.arpa is a collaboration between IETF (Internet Architecture Board) and ITU-T (Study Group-2) • SIP-T (Interworking SIP & ISUP) • Defines encapsulation of ISUP in SIP and mapping between SIP & ISUP fields • SIP-T architecture is approved document • SIP-ISUP mapping is close to approval • Current ITU-T SG 11 work on application for NGN-legacy network interworking

  30. International Work - IETF • Interworking SIP & H.323 • Requirements almost complete • Security and VoIP • TLS, Digest, S/MIME, IPSEC IETF protocols from Security Area • Used to secure SIP and SDP • SRTP • SIP Privacy/Identity work • MIDCOM (firewall control)

  31. International Work - IETF • Media Gateway Control • Megaco • MGCP • Transports for VoIP • SCTP • Signalling transport • New work begun on DCCP, unreliable protocol with congestion control properties • Service development • CPL (Call Processing Language) • SIP CGI (Applying HTTP service creation to SIP) • New work underway on Speech Services Control

  32. International Work - IETF • Accounting and Management • DIAMETER • AAA protocol • Signalling Compression • Robust Header Compression • Specifications for IP/UDP/RTP headers and the SIP/SDP messages to be compressed, especially for wireless VoIP uses.

  33. International Work - ITU • ITU-T Study Group 13 • Overall responsibility for IP work • Recommendations/areas of work include • Rec. Y.1541: Quantifying User QoS Needs in IP Terms • Rec. Y.1221: Traffic and Congestion Control in IP Based Networks • Leading ITU’s “NGN 2004” project

  34. International Work - ITU • ITU-T Study Group 11 • Responsible for signalling and interworking. Current work includes • Interactions between IN and IP-based networks • IP-related signalling protocols • Bearer (ATM, IP) Independent Call Control (BICC) • Signalling transport over IP • Use of SIP for user access and network-to-network interfacing • Has just initiated new projects on signalling control • between session control functions (across networks), • between session, resource and bearer control, and • between session control and user profile management. • Other new work on control architecture and signalling requirements about to commence.

  35. International Work - ITU • ITU-T Study Group 12 • Lead group for end-to-end transmission performance. Areas of work include • Transm. Req’ts for IP gateways and terminals • E-Model (model for speech quality incl.VoIP) • Transm. Plan. for VB, Data and Multimedia • Transm. of multiple interconnected networks • Voiceband services via IP networks • Multimedia QOS and perf. requirements • Effects of multiple IP domains on VoIP • QOS coordination in the ITU (as Lead SG) • In-service non-intrusive assessment of VoIP

  36. International Work - ITU • ITU-T Study Group 16 • Lead group for multimedia and convergence. Work includes • Voice Coding • Video Coding • Multimedia Signalling; including Data Conferencing, Modems, Facsimile, Call control and conference control and Media gateway control (H.248) • Security • Multimedia Architecture (H.323) • Mobility • Emergency Telecommunication Services

  37. International Work - ETSI • Considerable NGN work in all areas, including • TIPHON (VoIP and Multimedia) • SPAN (Signalling and interworking) • Security and Coding work • Co-ordinated by ETSI Board “NGN Implementation Group” • Major input to 3GPP IP work

  38. ACIF NGN Project • ACIF’s Strategic Plan in early 2001 identified need to work on “Next Generation Networks” • Meetings with ACA, ACCC and SPAN confirmed they had a similar interest. • ACCC sponsored an initial consultancy in second half of 2001 “to raise issues” • ACIF held an NGN seminar in May 2002 to scope the issues • Attendees proposed a continuing industry “conversation” on NGN matters.

  39. ACIF NGN Project • The ACIF Board agreed to support an ACIF NGN Project, working through the ACIF NGN Framework Options Group (“NGN FOG”). • The aim of the ACIF NGN Project is to help all involved discuss issues that cross current boundaries, including • Internet/telco divisions • Regulatory issues (ACA and ACCC) • Industry issues (including self-regulation requirements) • Policy issues • An early agreement was that user requirements must be the main driver of this work.

  40. NGN FOG Work • The main task of the NGN FOG is to assist understanding of the transition to next generation network equipment. The NGN FOG work involves consideration of issues including • Technical standards • End-user issues • End-to-end services • Interconnection across networks • Regulatory issues (both self-regulation and government regulation

  41. You are invited…. ……to help with this work Details at www.acif.org.au/ngn

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