crm customer relationship management 1 The information contained in this presentation is confidential information as per your terms and conditions with BT. Please do not forward, republish or permit unauthorised access. The content is accurate at the time of writing and is subject to change. BT Wholesale Planned Engineering Works (PEW) 90 day overview – October to December 2011.

BTW 2011 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. There is a current focus on efficient content delivery that will be offered through the Wholesale Content Connect product. 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. 2

20C Upgrades Prog No: UpgradeKey DriversUpgrades Complete / Total EUs per upgrade Upgrades per PEW Affected Products Av. End user outage (Mins) Upgrades per week Progress Planned End Sept Oct Nov Dec 20C BRAS Code Upgrade Stability8/117Av Min 3000 Max IPSC452-4 Mar12 20C DSLAM Cards Capacity530/2801Av 250Up to 60IPSC3300 Mar 12 Key:- Outage is defined as full loss of service Planned month for upgrades Contingency month for upgrades – 20% likelihood Contingency month for upgrades – 50% likelihood See diagram on slides 8&9 for network location High Impact Programme Programme Complete 2 3 # 14 20C BRAS code – This upgrade introduces revised code to improve the stability of the ESR BRAS 20C DSLAM – To manage additional capacity demands, new lines cards will be provisioned in existing DSLAM’s

21C Upgrades Prog No: UpgradeKey DriversUpgrades Complete / Total EUs per upgrade Upgrades per PEW Affected Products Av. End user outage (Mins) Upgrade s per week Progress Planned End Sept Oct Nov Dec 21C BRAS Core Migration Capacity164/302Non Customer Impacting Up to 12WBC Dec 11 SVLAN moves Capacity, Stability OngoingAv 800 Min 0 Max – 5WBC35Up to 75 Ongoing Access MCLAG Resilience382/589Av 2500 Min 0 Max WBC Mar 12 MPLS Core Router Upgrades Code UpdatePhase 1 80/83 (No Customer impact) Phase 2 1/25 Av Min 0 Max WBMCPhase 1 – No Outage Phase (240 Max) 1-4 Feb 12 MSE Upgrades Capacity0TBA1WBC MEAS ETHERNET 5-8 minutesTBA (will not start until 2012) 3 6 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 21C BRAS (Ericsson) Required to complete the capacity enhancement as a follow on from the code and card programme – 151 Core Migrations and 151 8G Throughput Upgrades 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 9 11 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 20

21C Upgrades Progr No: UpgradeKey DriversUpgrades Complete / Total BB EUs and/or Ethernet Circuits per upgrade Upgrades per PEW Affected Products Av. End user outage (Mins) Upgrades per week Progress Planned E nd Sept Oct Nov Dec Copper MSAN Upgrade Functionality2838/4562Non- Customer Impacting Up to 120None0Up to 480 Jan 12 EAD Chassis Code Upgrade Stability2837/6950Up to 15 Ethernet Circuits Up to 200Ethernet, Mobile Ethernet <1Up to 1000 Feb12 BEA VS Card Upgrade Capacity9/20Non- Customer Impacting 1None0Up to 4 Jan 12 Copper MSAN Upgrade 2 nd vendor Stability223/ WBC2Up to 360 Dec 12 The EAD Chassis Code Upgrade is required to provide greater stability Copper MSAN Upgrade – this is a code upgrade to enable TV Connect Services Broadband Edge Aggregator Card Upgrade - this change provides a new port card to increase the current capacity capability Copper MSAN upgrade for 2 nd vendor to increase platform stability. 21

Completed 20C Upgrades Progr No: UpgradeKey DriversUpgrades Complete / Total BB EUs and/or Ethernet Circuits per upgrade Upgrades per PEW Affected Products Av. End user outage (Mins) Upgrades per week Date Ended 20C BRAS Code & Card Functionality/ Stability Pt /194 Pt /194 Av Min 3000 Max IPSC12018– 48 Oct11 6 1

Completed 21C Upgrades Progr No: UpgradeKey DriversUpgrades Complete / Total BB EUs and/or Ethernet Circuits per upgrade Upgrades per PEW Affected Products Av. End user outage (Mins) Upgrades per wee Date Ended 21C BRAS code & card upgrade Stability, Capacity, Functionality 151/151Av Min 0 Max WBC Oct11 Provider Edge switch Separation Capacity15 / 15Av WBMC (host link) Apr Code Upgrade [EES, EEA & IEA ] Capacity1230/1230 BB EU’s Av Max Ethernet: Av 60 Ccts Max 990 Ccts 1WBC MEAS ETHERNE T 560 – 100 Jun 11 Copper MSAN Stability78/78Av 600 Min 0 Max WBC37-44 July 11 EFM Code Upgrade Functionality768/ 768Ethernet Av 7 Ccts Max 60 Ccts 1ETHERNE T (Copper Access Only) 15 (30 max) Jun

8 Completed 21C Upgrades Progr No: UpgradeKey DriversUpgrades Complete / Total BB EUs and/or Ethernet Circuits per upgrade Upgrades per PEW Affected Products Av. End user outage (Mins) Upgra des per wee Date Ended FER MCLAG & Virtual Switch Resilience, Capacity 14 / 14Av Min 1000 Max WBMC (host link) Aug Minor Code UG Stability476/476Non- Customer Impacting 1None Aug 11 BEA VS IOS Code Upgrade Stability20/20Av WBC20Up to 8 Nov 11 Copper MSAN Upgrade Stability560/560 Completed Av 500Up to 25WBC3Up to 100 Oct

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. 9

Broadband Services on 21CN

21CN Core EEA/EES F EEA/EES Key ETHC Ethernet Circuit ETHA Ethernet Access (Fibre/Copper) 7750 Edge Router EFM Router Customer / CP Site Ethernet Service on 21CN EEA/EES F EFM ADVA Chassis 16

Descriptions Colossus refers to BT's 20C UK core Internet backbone network mesh which runs on IP technology DSLAM - A Digital Subscriber Line Access Multiplexer (DSLAM, often pronounced dee-slam) allows telephone lines to make faster connections to the Internet. It is a network device, located in the telephony exchanges of the service providers, that connects multiple customer Digital Subscriber Lines (DSLs) to a high-speed Internet backbone line using multiplexing techniques. BRAS - A broadband remote access server (BRAS or BBRAS) routes traffic to and from the digital subscriber line access multiplexers (DSLAM) on an internet service provider's (ISP) network. The BRAS manages the logical path from the consumers modem through to the IP core network. Fibre MSAN – Fibre MSAN provides both direct access for Fibre fed customer services and aggregation/resilience protection to the Network. MSAN is essential a next generation DSLAM. This is essentially the edge of 21C transmission backhaul. Copper MSAN -Copper Multi Service Access Node equipment provides all Access for Copper/Metallic fed services, PSTN Voice DSL, Broadband, Slow Speed Ethernet and converts the end user service to IP. EEA – Ethernet Edge Aggregator (a 7750) EFM – Ethernet in the First Mile. Ethernet over copper access IEA – Internet Edge Aggregator (a 7750) EES – Ethernet Edge Switch (a 7750) MSIL - Multi-service Interface Link is the Ethernet pipe connectivity between BT’s and CPs’ 21CN networks. MSIL provides for the needs of WBC, WBC (Converged) and NGN Call Conveyance. BEA - Broadband Edge Aggregator. FER – Front End Router MSPE – Multi-service Provider Edge Takes 20C BRAS capability closer to the end user. Less latency. MCLAG – Multi-chassis Link Aggregation Group – NGA – Next generation architecture. Fibre based internet access such as FTTC/FTTP (Fibre to the cabinet/premises) GEA – Generic Ethernet access, allows local loop equipment (e.g. Openreach) to be connected to fibre. EU – End User. The consumer or business that uses the WBC connection Access Node – A local exchange containing one or more MSANs Metro Node – The backhaul network from the Access Nodes terminates on the metro nodes. Core Node – One of 20 sites where WBC traffic is aggregated and handed over to CPs LPA - Logical PoP Aggregator (a router that aggregates the traffic from BRASs at a 20C broadband point of presence) MPLS Core- Multi-Protocol Label Switching Core network. A high speed IP network, where packets are given a predefined route and pass straight through, Unlike a normal IP network where each packet is inspected and routed by each node in the network. AP - Aggregation Point. This is where multiple end users are aggregated into a single path for connection to the CP. Allow CPs access to broadband end users EP - Extension Path. This is the connection from the AP at the WBC Interconnect Node to the CP. Multiplexing – Many of these network elements perform the same functions of multiplexing many transmission pathways onto a single pathway, such that a point is reached where a single physical connection can route connections into an ISPs network. Alcatel 7750 Infrastructure Ethernet Aggregation Switch (IP Multiplexor) 12

Management of risk In addition to the standard risk mitigation that would be in place for any network upgrade project, BT is applying additional rigour as outlined below:- – Co-ordination of PEW activities to avoid co-incident clashes with other network and systems changes. – Geographical rollout to focus Field Engineering resource and spares for 72 hour post-PEW support following higher-risk PEWs – Daily calls to sanction all PEW activity for following night based on latest available information – Separate Go / No go calls for all key upgrades – On-the-night efficiencies to reduce risk of failures and overruns. – Combinations of co-incident BRAS upgrades scheduled to minimise impact on RADIUS servers – Additional resource being mentored to widen the skill sets and spread available hands – Review of previous night’s PEWs with full root-cause analysis of issues and over-runs and mitigations put in place to minimise re-occurrences 13