1. 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. 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. 3 BTID Network Change – Major Project Summaries 22 Network change StatusProgramme Number Summary MSPE software upgrade. Status – 8 Core upgrades remain to be completed Code upgrade (3.9.1 + SMU patches) is required on the Cisco MSPE to improve platform stability. Next upgrade planned for Stepney Green 10th May. Completion is targeted for 31 st May. 11

4. 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 12th site for WCC resilience complete on 9 th May. 8 more remain to be completed for WCC Upgrade of 6th device complete for WBMC resilience on 9 th May. 7 remain to complete for WBMC shared. Plan for expedited WBMC upgrade programme is now in place. 23

5. 5 BTID Network Change – Major Project Summaries 29 Network change StatusProgramme Number Summary 21c BRAS Card replacement Status – Deployment Ongoing (83% complete) Replace line-cards in 21c BRAS Deployment of DDR cards is progressing. 190 routers completed to date. Revised plan completes 11 th May. 28

6. 6 BTID Network Change – Major Project Summaries 26

7. 7 20C Upgrades Edinburgh LPA– To meet ongoing 20c usage growth bigger LPA is required. 29

8. 8 21C Upgrades 6 9 11 20 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

9. 9 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. Linecard hardware replacement to prevent no customer impacting card failures. 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) Upgrade s per week Progress Planned End Feb Mar Apr may EEA – EES Backhaul Uplift Capacity215/1060Non Customer impacting 40None05 Jan13 High Throughput BEA-VS Capacity2/5Av 120K1WBC / WCC 45 mins1 June 12 2 nd Vendor MSPE Stability18/51Av 20k1WBC / WCC / Ethernet 30 secs – 10 mins 2 May 12 BRAS software Upgrade Stability25/200 Av 17000 Max 32000 1WBC / WBMC/ WCC 45 minsUp to 50 May 12 Copper MSAN Software Upgrade Stability / Capacity 3721/5844 Average 700 120WBC / WBMC 30 mins480 May 12 DDR Card replacement Stability190/200Non Customer impacting 10None050 May 12 24 22 23 26 27 28 EEA – EES 7750 Lag Migration - This change provides increased scalability.

10. 10 Completed 20C Upgrades 1 14 2

11. 11 Completed 21C Upgrades 3 5 8 10 12

12. Completed 21C Upgrades 7 13 19 18 21

13. 13 Completed 21C Upgrades 15 16 3 17

14. 14 Re-planned PEWs The level of network change that BTW is driving through inevitably leads to a need to re-plan a number of PEWs. The reasons for these re-plans include:- unforeseen technical issues specific to (or indirectly impacting) that programme, re-prioritisation of work, insufficient time to complete all work on the night and operational decisions. BTW have made some improvements to the management of re-planned PEWs and where possible will seek to avoid using Emergency PEWs for this re-planned work. In some cases re-planned work will need to be carried out with less notice.

15. 15 Broadband Services on 21CN 29 27 9 24 20 6 28 26 22 23 11

16. 16 Ethernet Service on 21CN

17. 17 Descriptions

18. 18 Management of risk