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 February 2013 to May 2013 These dates are indicative dates only and not to be used for any forecasting purposes as they are all subject to change. Please ensure that you wait for formal notifications from IRAMS.

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 Customer Service / BTID Network Change - Executive Summary Deployment Priorities Feb – Apr 2013 Prog No: UpgradeKey DriversTotal Upgrades Average EU Impact per upgrade Affected Products Average EU outage (Mins) Upgrades per week Target Months Targat End Jan FebMar Apr 2 nd vendor MSPE Upgrade Functionality (LAG Support) 80Non-service impacting None05 May 13 LAG DeploymentResilience, scaling, stability. IEA-P, EEA-P, P-P, MSPE-P TBC0None04 Ongoing 500G IEA chassis upgrade Scaling 4 port 10G line-card TBC TBA 2nd vendor P card Upgrade ScalingTBC TBA MSE MigrationsScaling, Functionality 200k EU WBC / WBMC Ongoing MSE Infrastructure & CP Build Scaling420Non-service impacting None04 Ongoing

4 Customer Service / BTID Network Change - Executive Summary Deployment Priorities Sept – Dec 2012 – Customer View WBMC Dedicated Planned Upgrade Programmes and EU outage in minutes. Notes – No customer could be impacted by every outage. e.g. A customer would not be impacted by both HT-BEA migration and HT-BEA sw upgrade. Difficult to assess what this means for a typical customer. Next steps – Proposal attached

5 Ongoing 21C Upgrades 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 Dec Jan Feb mar SVLAN moves Capacity, Stability OngoingAv 800 Min 0 Max WBC35Up to 75 Ongoing Access MCLAG Resilience460/520Av 2500 Min 0 Max WBC Mar13 EEA – EES Backhaul Uplift Capacity1041/1060Non Customer impacting 40None05 Jan 13 2 nd Vendor MSPE Stability51/51 Complete Av 20k1WBC / WCC / Ethernet 30 secs – 2 mins 2 Jan13 CRS SMU Upgrades Stability33/52Non Customer impacting 1None016 Mar 13 HT-BEA IOS-XR Upgrade Functionality 1/6Average 200k 1WBC / WCC 15 mins1 Mar 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 24 EEA – EES 7750 Lag Migration - This change provides increased scalability. 23 To increase platform resilience a 2 nd vendor MSPE is being introduced. 31 Software upgrade to increase platform stability. 35 Software upgrade to support BTR 40G Product requirements

6 Ongoing 21C Upgrades Cont’d Prog No: UpgradeKey DriversUpgrades Complete / Total EUs per upgrade Upgrades per PEW Affected Products Av. End user outage (Mins) Upgrad es per week Progress Planned End Dec Jan Feb Mar BRAS P8 Upgrade Functionality (IPv6), stability. 12/248BB EU’s per BRAS Av Max WBC / WBMC 45Up to 24 Apr-13 High Throughput BEA-VS Capacity7/10Av 120K1WBC / WCC 45 mins1 Mar-13 2 nd vendor MSPE Software Upgrade Functionality (Lag Support), stability. 0/80None1 4 May-13 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

7 Ongoing 20C Upgrades Cont’d Prog No: UpgradeKey DriversUpgrades Complete / Total EUs per upgrade Upgrades per PEW Affected Products Av. End user outage (Mins) Upgrad es per week Progress Planned End Dec Jan Feb Mar 10k BRAS SB11 Stability 17/122Av Min 3000 Max WBC35Up to 18 Feb 13 36

8 Completed 20C Upgrades

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

10 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 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 12 MPLS Core Router Upgrades Code Update109/109 Av Min 0 Max WBMC 180 (240 Max) 1-4 Jun

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) Upgrades per week Date Ended High Throughput BEA-VS Capacity5/5Av 120K1WBC / WCC 45 mins1 Jun 12 BRAS software Upgrade Stability193/193 Av Max WBC / WBMC/ WCC 45 minsUp to 50 Jul 12 Copper MSAN Software Upgrade Stability / Capacity 5844/5844 Average WBC / WBMC 30 mins480 May 12 2 nd vendor MSAN Upgrade Stability702/702Average WBC / WBMC/ WCC 40 mins Jul

Broadband Services on 21CN

13 Ethernet Service on 21CN

14 Descriptions

15 Management of risk