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 – June to August 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. All the activities outlined on slides 2, 3 and 4 involve an end user outage. 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 May June July August 20C BRAS Code & Card Functionality / Stability Pt /194 Pt /194 Av Min 3000 Max IPSC12018– 48 May 11 20C BRAS Code Upgrade Stability8/117Av Min 3000 Max IPSC452-5 Aug 11 20C DSLAM Cards Capacity0/3000Av 250Up to 60IPSC3300 Nov 11 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 1 3 # 20C BRAS code & card – this upgrade was needed to get the Juniper ERX BRAS ready for HQOS which is required for WCC (content). - COMPLETE 14 20C BRAS code – This upgrade introduces revised code to improve the stability of the ESR BRAS 2 20C DSLAM – To manage additional capacity demands, new lines cards will be provisioned in existing DSLAMs

21C 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 May June July August 21C BRAS code & card upgrade Stability, Capacity, Functionality 150/151Av Min 0 Max WBC July 11 Provider Edge switch Separation Capacity15 / 15Av WBMC (host link) SVLAN moves Capacity, Stability 1100 / 1100 BAU - Ongoing* Av 800 Min 0 Max – 5WBC Ongoing FER MCLAG & Virtual Switch Resilience, Capacity 12 / 14Av Min 1000 Max WBMC (host link) Aug Code Upgrade [EES, EEA & IEA ] Capacity1230/1230 BB EUs Av Max Ethernet: Av 60 Ccts Max 990 Ccts 1WBC MEAS ETHERNET June C BRAS (Ericsson) code & card upgrades - Required to improve capacity capability, new functionality to support TV services and stability Provider Edge switch separation – these upgrades increase core capacity – directly benefits WBMC Shared and Ethernet - COMPLETED SVLAN moves - these moves offload SVLANs (bundles of Broadband traffic) from one BRAS to another. This is carried out to alleviate capacity issues upgrades (complete). FER MCLAG & Virtual Switch – two separate upgrades that together improve capacity and resilience of WBMC shared code upgrade – these Multi- service boxes are located at different points of the network. This upgrade indirectly enhances the capacity of these boxes (allowing new hardware to be used) and is a pre-requisite for TV Connect - COMPLETED

21C Upgrades Progr No: UpgradeKey DriversUpgrades Complete / Total BB EUs and/or Ethernet Circuits per upgrade Upgrade s per PEW Affected Products Av. End user outage (Mins) Upgrades per week Progress Planned E nd May June July August Access MCLAG Resilience247/ 562Av 2500 Min 0 Max WBC Dec 11 Copper MSAN Stability71/78Av 600 Min 0 Max WBC37-44 Jul 11 MPLS Core Router Upgrades Code UpdatePhase 1 21/83 (No Customer impact) Phase 2 1/25 Av Min 0 Max WBMCPhase 1 – No Outage Phase (240 Max) 1-4 Feb 12 EFM Code Upgrade Functionality768/ 768Ethernet Av 7 Ccts Max 60 Ccts 1ETHERNET (Copper Access Only) 15 (30 max) Jun Minor Code Upgrade Stability62/476Non- Customer Impacting 1None Sept EFM Code Upgrades – Required to upgrade code to provide greater service assurance functionality - COMPLETE 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. Copper MSAN upgrades – Stability update on MSAN single card Access MCLAG – removes single point of failure between MSAN (mostly Fibre MSAN which could aggregate several Copper MSANs) and Metro Node to improve overall availability 7750 Minor code upgrade – Required to improve software stability – Starts 21/06/11 13

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

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 BTs 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) 8

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 nights PEWs with full root-cause analysis of issues and over-runs and mitigations put in place to minimise re-occurrences 9