1 The information contained in this Presentation is confidential information as per your terms and conditions with British Telecommunications plc (BT). Please treat it accordingly and do not forward, republish or permit unauthorized access. BT reserves the right to make changes to the information in this Presentation at any time without further notice. BTW Planned Engineering Works 90 day overview May to July 2012

2 BTW 2012 Network Changes – 3 month rolling plan Whilst BTW has continually worked to enhance its network, we are currently undergoing an exceptional level of change driven by four main drivers:- –Stability – to improve the reliability of the network, BTW is targeting certain network elements with hardware and software improvements. –Capacity – the need for additional capacity is driven by an increase in the number of broadband users on the 21C network (through migration from 20C and growth) and also by the ever-increasing bandwidth demands of those users. –Resilience –to improve the resilience of the network, BTW is actively removing single points of failure from the network –New Functionality – to meet the needs of the market BTW needs to enhance its network to deliver the services its customers require. This presentation outlines the key upgrade programmes, their drivers, customer impact and the number of upgrades per programme per week. BTW is keen to deliver all the required improvements as quickly as possible whilst actively managing the risk to customers. For this reason a range of run-rates against each programme has been outlined. The actual run-rates achieved will be determined by this ongoing live analysis of risk. Customer outage times for the PEWs start between 00:01 and 02:00 with the aim of completing customer impacting work by 04:00. This allows 2 hours for roll-back should the PEW be unsuccessful. Business as usual capacity upgrades and upgrades to resilient structures have not been listed here.

3 BTID Network Change – Major Project Summaries Network change StatusProgramme Number Summary MSPE software upgrade. Status – 3 Core upgrades remain to be completed Code upgrade ( SMU patches) is required on the Cisco MSPE to improve platform stability. Two upgrades complete since last report – Edinburgh and Preston. Completion is targeted for 13 th June. 11 Network change StatusProgramme Number Summary HT BEA-VS Introduction Status – Deployment ongoing Introduce High throughput BEA-VS into the 21c platform 3rd migration at Glasgow completed on 17 th May. Next site will be Colindale on 7 th June. Pre-Olympic scope of this project is 5 sites to be completed by 5 th July. 22

4 BTID Network Change – Major Project Summaries 20 Network change StatusProgramme Number Summary 2 nd Vendor MSPE Status – Deployment Ongoing Introduce 2 nd vendor MSPE for WCC and WBMC shared resilience. Upgrade of 17th site for WCC resilience complete on 30 th May. 6 more remain to be completed for WCC Upgrade of 12th device complete for WBMC resilience on 30th May. 1 remain to complete for WBMC shared. 23

5 BTID Network Change – Major Project Summaries Network change StatusProgramme Number Summary 21c BRAS Software Upgrade Status – Deployment Ongoing (37% complete) Upgrade software on 21c BRAS to fix known defects. Defects in the software which will require resolution. BAU deployment is now proceeding, 74 now upgraded. Upgrade plan is agreed, current plan for software is to complete by 6 th July. 26 Network change StatusProgramme Number Summary 2 nd vendor MSAN Software Upgrade Status – Deployment Pending Upgrade software on 2 nd vendor MSAN to fix known defects. Resolves software defects. 183 out of 688 upgrades complete. Deployment completion due19th June. 3030

6 20C Upgrades Prog No: UpgradeKey Drivers Upgrades Complete / Total EUs per upgrade Upgrade s per PEW Affecte d Product s Av. End user outage (Mins) Upgrad es per week Progress Planned End May June July Aug Edinburgh LPA Capacity2/2Non customer impacting 1None01 May Edinburgh LPA– To meet ongoing 20c usage growth bigger LPA is required.

7 21C Upgrades SVLAN moves - these moves offload SVLAN’s (bundles of Broadband traffic) from one BRAS to another. This is carried out to alleviate capacity issues mplet Access MCLAG – removes single point of failure between MSAN (mostly Fibre MSAN which could aggregate several Copper MSAN’s) and Metro Node to improve overall availability MPLS Core Router Upgrades required as existing software is soon to become “End of Life”. Phase 1 commenced no customer impact. Phase 2 due to commence Dec 11. MSE Upgrades- Provide BB edge functionality on 7750 switches and additional BB capacity. Achieved by upgrading existing Ethernet Edge devices Prog No: UpgradeKey Drivers Upgrades Complete / Total EUs per upgrade Upgrades per PEW Affected Products Av. End user outage (Mins) Upgrad es per week Progress Planned End May June July Aug SVLAN moves Capacity, Stability OngoingAv 800 Min 0 Max – 5WBC35Up to 75 Ongoing Access MCLAG Resilience460/520Av 2500 Min 0 Max WBC Dec 12 MPLS Core Router Upgrades Code Update Phase 1 83/83 (No Customer impact) Phase 2 23/26 Av Min 0 Max WBMCPhase 1 – No Outage Phase (240 Max) 1-4 Jun 12 MSE Upgrades Capacity2/70Various1WBC MEAS ETHERN ET 5-8 minutes TBA (will not start until 2012) Sept

8 21C Upgrades Additional BEA capacity is required and this is being achieved by introducing a bigger switch. To increase platform resilience a 2 nd vendor MSPE is being introduced. 21c BRAS software upgrade to increase stability of the platform Software upgrade which supports new line cards for capacity and stability benefits and also delivers energy efficiency savings. Progr No: UpgradeKey Drivers Upgrades Complete / Total BB EUs and/or Ethernet Circuits per upgrade Upgrade s per PEW Affected Product s Av. End user outage (Mins) Upgrades per week Progress Planned End May June July Aug EEA – EES Backhaul Uplift Capacity285/1060Non Customer impacting 40None05 Jan13 High Throughput BEA-VS Capacity3/5Av 120K1WBC / WCC 45 mins1 June 12 2 nd Vendor MSPE Stability29/51Av 20k1WBC / WCC / Ethernet 30 secs – 10 mins 2 June 12 BRAS software Upgrade Stability74/200 Av Max WBC / WBMC/ WCC 45 minsUp to 50 July 12 Copper MSAN Software Upgrade Stability / Capacity 5642/5844 Average WBC / WBMC 30 mins480 May 12 2 nd vendor MSAN Upgrade Stability183/688Average WBC / WBMC/ WCC 40 mins June EEA – EES 7750 Lag Migration - This change provides increased scalability. 3030

9 Completed 20C Upgrades

10 Completed 21C Upgrades

11 Completed 21C Upgrades

12 Completed 21C Upgrades Progr No: UpgradeKey Drivers Upgrade s Complet e / Total BB EUs and/or Ethernet Circuits per upgrade Upgrad es per PEW Affecte d Product s Av. End user outage (Mins) Upgrade s per wee Date Ended Copper MSAN Upgrade Function ality 5594/5594Non- Customer Impacting Up to 120None0Up to 480 Dec 11 EAD Chassis Code Upgrade Stability6950/6950Up to 15 Ethernet Circuits Up to 200Ethernet, Mobile Ethernet <1Up to 1000 Feb 12 21C BRAS Core Migration Capacity151/151Non Customer Impacting Up to 12WBC Feb 12 BEA VS Card Upgrade Capacity20/20 – Complete Non- Customer Impacting 1None0Up to 4 Mar 12 DDR Hardware replacement Stability200/200Non Customer impacting 10None050 May

13 Broadband Services on 21CN

14 Ethernet Service on 21CN

15 Descriptions

16 Management of risk