Consult21 Information is subject to change and is for discussion purposes only. Any dates/timings are the current anticipated timescales and may be subject to change. 1 Migration Provisioning Plan Management The purpose of this presentation is to outline to Communications Providers BT’s view of:  how the transition to an 18 month process will be handled from an operational perspective (slides 2 & 3) through provision of an example BT 21CN implementation programme for CP Interconnect migration from closing DLEs to NGSs  the milestones which BT believes it should be tracking with Industry at the Implementation & Migration Working Group at an Industry level (slides 4 & 5) Additionally this presentation informs Communication Providers on the system BT is developing to support this process (slide 6) Ron Riches

Consult21 Information is subject to change and is for discussion purposes only. Any dates/timings are the current anticipated timescales and may be subject to change. 2 21CN CP Interconnect Migration: Example Implementation Programme The purpose of the example (slide 3) is to show how we may reach the required standard 18 month migration timeline and quarterly SAN issuing Tranches as soon as is practically possible. In the example illustrated, this point will be reached at Tranche 5 After this point, SANs will be issued quarterly, in January, April, July and October with each SAN issued covering a 3 month period of the DLE to MSAN programme When reviewing this example, communication providers are asked to note:  Tranche 1 will cover 4 months to align with the Pathfinder timescales proposed in the Migration proposal (issued 21/10/05)  Tranche 2 will then cover 1 month to align the quarterly SAN issuing programme  Each box equates to a one month time period  Any variation in phase length in the timeline (from those in the standard 18 month timeline) is explained on the right hand side of each Tranche

Consult21 Information is subject to change and is for discussion purposes only. Any dates/timings are the current anticipated timescales and may be subject to change. 3 21CN CP Interconnect Migration: Example Implementation Programme

Consult21 Information is subject to change and is for discussion purposes only. Any dates/timings are the current anticipated timescales and may be subject to change. 4 21CN CP Interconnect Migration: Example Implementation Programme Milestones ADMINISTRATION PHASE MILESTONES: HLSAN : The production by BT, and the issuing to the impacted CPs, of the HLSANs (High Level SAN) for those DLEs closing within the Migration Tranche. DSAN : The production by BT, and the issuing to the impacted CPs, of the DSANs (Detailed SAN) for those DLEs closing within the Migration Tranche. Technical Negotiations : Based on the DSANs issued, bi-lateral technical negotiations between the CP and their BT Technical Account Manager (TAM), leading to an agreement on the DLE to NGS traffic and physical transfer method(s) to be used for each CP route and E1 connected to the closing DLE. Cost Negotiations : Bi-lateral negotiations between the CP and their BT Commercial Manager (CM), based on the agreed DLE to NGS transfer method(s) to be used for each CP route and E1 connected to the closing DLE, leading to an agreement on any CP's SAN related costs. ACOs : The production and issuing of an ACO (Advanced Capacity Order) to BT, by either the CP or BT, for the transfer of the CP's traffic and physical interconnect to the NGS from the DLE, based on the method(s) agreed during the joint negotiations. PREPARATION PHASE MILESTONES: Orders : The production and the issuing of an order, by either the CP or BT, for the transfer of the CP's traffic and physical interconnect to the NGS from the DLE, based on the method(s) agreed during the joint negotiations. RFT : Orders placed will be progressed by BT up to Ready For Test (RFT) status

Consult21 Information is subject to change and is for discussion purposes only. Any dates/timings are the current anticipated timescales and may be subject to change. 5 21CN CP Interconnect Migration: Example Implementation Programme Milestones PREPARATION PHASE MILESTONES (CONT): Review: A joint BT TAM and CP review of the transfer method(s) and capacities agreed during the SAN negotiations. TRANCHE ALIGNMENT TIME: No activities are planned to take place in the period. It is required to align the SAN issuing quarterly Tranches with the DLE to MSAN programme months. TRANSFER PHASE MILESTONES: Traffic & Physical Transfer: DLE to NGS : The transfer of the CP's traffic and physical interconnect to the NGS from the closing DLE, together with any agreed post transfer testing. STABILITY PHASE: No Activities: No closing DLE to NGS CP Interconnect Migration activities are allowed to take place within this phase NETWORK FREEZE PHASE: Absolutely No Activities: Absolutely no closing DLE to NGS CP Interconnect Migration activities are allowed to take place within this phase. DLE TO MSAN PHASE: End Users Transfer - DLE To MSAN: The transfer, by BT, of end users from the closing DLE's concentrators to 21CN MSANs.

Consult21 Information is subject to change and is for discussion purposes only. Any dates/timings are the current anticipated timescales and may be subject to change. 6 21CN CP Interconnect Migration: MIME High Level Overview MIME is an internal BT system under development to manage a number of Transfer Engineering related activities - but primarily Interconnect Migration Key workflow management areas supported are :  Tracking overall programme progress  Scheduling of an individual's tasks  Tracking of task achievement & overall migration progress  Task & assignment jeopardy management  Cost tracking Key automation areas supported are :  HLSAN & DSAN production & issuing  TAM & CM to CP interaction  Shadow ACO & Order production  Interaction to existing BT OSS  Route & E1 provision & recovery  Route & routing data provision