1. INTERCONNECT WORKING GROUP 28 JANUARY 2005 BT’s Thinking about Next Generation Interconnect in 21CN DARYL DUNBAR HEAD OF 21CN CUSTOMER SOLUTIONS The information in this presentation relates to plans currently under development and subject to consultation, and may be subject to change. Detailed implementation depends upon a number of factors including the capabilities of suppliers and the final 21CN network design.

2. Interconnection Today Distance and Element Based Voice Stovepiped NNIs for Frame and ATM, not IP Partial Private Circuits using PDH/SDH

3. Vision of Interconnection in 201x Converged Fat-Pipe SDH Interconnects (e.g. STM-16) Voice as Data Application (e.g. SIP over IP NNI) “Death of Distance” (e.g. Handful of Interconnect Pipes at Key Nodes)

4. Interconnect Transition Planning Parameters Demand Drivers for New-Wave Services Access Mode and Protocols Cost Management Commercial Interconnection Products and Regulation

5. Demand Drivers for Wholesale New-Wave Services OLO Product Planning for Next-Gen Voice and Data Services Service Providers Expected to Enter Voice Market Brand New Entrants Expected (e.g. Vonage for Global VoIP)

6. Access Mode and Products Sustain PSTN C7-based TDM to NGS Tandems (E1, IUP or ISUP) C7-based TDM to 21CN Media GWs (STM-1, UK ISUP) Replicate PSTN C7 Encapsulated in SIP over IP Transport (SIP-I aka ITU-T Q1912.5) Transform PSTN SIP over IP NNI (pure-play, no C7 constraint) Transform Data NNI Would support both SIP and a multi-operator “MPLS-like” data standard

7. Cost Management Line Cost Optimisation BT recognises the need of our customers to predictably optimise line cost But, flattening the network is beneficial to all in the long term And converged interconnection will reduce all our costs Re-Arrangement Cost Minimisation BT recognises that re-arrangement of interconnect circuits is costly So, we are working on a plan that minimises forced TDM migration While we mutually plan for next-generation interconnects Legacy Interconnect Proposal Details Follow Later Today

8. Interconnect Product Prioritisation How should we prioritise? Classic problem: Together we can do 2 well, but doing 3 is very hard We must Sustain; but, should second be Replicate or Transform? Transform (Pure-Play SIP over IP NNI) Sustain (C7 over TDM) Replicate (C7 encapsulated in SIP over IP Transport)