1. BT’s 21CN Compatibility testing & engagement programme. November 2008.
Mike Piggott
&
Paul ffitch
Caution advised. Some of the information in this presentation relates to plans subject to consultation and therefore change.

2. Agenda:- 21CN Programme update CPE Implications
Testing & result publication
Manufacturer/Industry Association engagement
Internal/external operational readiness monitoring
End user comms
Industry comms
Test failure spreadsheet
Critical CPE special treatments
Line reversion process
Grooming process
CPE diagnostic process
Escalation route for utilities & environment agency
Pro-active external trials
PF+ learning objectives
RFI process
These are the topics I’d like to cover today.
I’ll start by putting CPE testing into the context of the wider programme and where that’s up to, explain the implications of 21CN for CPE, talk about testing, the external engagements that support it and then overview some of the activities, tools and resources that have been put in place to support our industry and our customers’ experience listed here.

3. 21CN – the programme has evolved
Continual customer feedback helps to inform and enhance the programme
Now prioritising the delivery of next generation services ahead of replicating old services
Introducing windows for voluntary upgrades to new services before planned migration
The scope of 21CN has also been expanded, to include:
The introduction of software-driven innovation capabilities
More detailed components for enterprise customers
New technology to improve mobile access
Consistency between 21CN and NGA
So, starting with the programme, there is no doubt that since inception it has evolved in response to customer feedback and moves and changes in the market. This has led to a revised deployment strategy where delivering new services has been prioritised over replicating existing ones and where CP’s have a window of opportunity to voluntarily migrate customers to the new platform before the programme implements planned migrations.
The programme has also evolved in scope to include SDK’s that will allow BT and third parties to develop software driven capabilities to overlay on the network infrastructure. For example message and call routing could be driven by events in business and workflow processes, there could be integration with mobility and self service capabilities.
And finally, the synergies between the 21CN programme and Openreach’s NGA programme are being realised. For example w are looking at CPE compatibility testing together.

4. 21CN – Objective remains unchanged
Legacy network
21CN platform
PSTN Migration
Converged Core
Class 5
Call Server
Fibre or Copper
WWW
DSL
IP-MPLS-WDM
Content
ISP
But having said all that, the end game is still the same. The transformation of the current BT networks to a single multiservice network architecture based on IP technology.
The legacy networks will ultimately be closed down and the 10’s of thousands of network elements across around sites reduced to fewer components in around 5000 sites.
End User
~5k nodes
~100 nodes
17 networks to ONE global platform

5. Advantages of 21CN Reliability Performance Cost Resilience Features
Faster new service delivery
Software innovation
PSTN Migration
Converged Core
Class 5
Call Server
Fibre or Copper
WWW
DSL
IP-MPLS-WDM
Content
ISP
For our customers, this enhances reliability with a far simpler network with fewer components, performance is improved and faster bigger better products enabled as a result such as faster broadband, 10Gb ethernet products.
It facilitates a cost base transformation for Bt which ultimately means competitive pricing to customers, in a single platform, network resilience can be built in to a greater degree and new products and services will be able to be delivered much faster to market.
Additional features will be enabled on the new 21CN products and with open SDk’s, innovation will become a reality.
End User
~5k nodes
~100 nodes

6. 21CN - key milestone overview
So lets look at the timelines briefly before focusing on CPE related activities.
We are currently running trials known as PF 1 in the S. Wales area which involves the volume migration of PSTN lines to the 21CN platform.
We are also currently in the process of scoping phase II trials with CP’s.
But the key date on here is a line down the middle of this plan – April That’s when we start mass or volume PSTN migrations to 21CN nationally.
Similar ISDN volume migrations will follow about a year later.
But earlier than that – from late summer ’09, there may be an opportunity for CP’s to voluntarily adopt WBCC which is a wholesale broadband and voice converged product at a single price point that alllows CP’s to implement their own call server technologies. This won’t be available nationally, but may be adopted in some geographies by some CP’s.
As this slide also implies, 21CN delivered BB and ethernet products are already available to CP’s to buy. BB was launched in April with about a 5% footprint that will grow to 40% by April ’09 and Ethernet was launched at 100 sites in April growing to around 600 sites by April ’09.

7. Services on 21CN vs. legacy
PSTN:
New PSTN line cards in new MSAN edge equipment.
IP packet based transport of voice data (legacy PSTN uses switched circuit transport).
ISDN:
New ISDN line cards in new MSAN edge equipment.
Broadband:
New ADSL/ADSL2+ line cards in new MSAN edge equipment.
Same IP packet based transport as existing broadband.
Some of these changes cause certain characteristics to differ from those on the existing network.
So what does all that mean for CPE ?
Essentially the introduction of this brand new network means that at the edge of our network in the local exchange buildings, PSTN & ISDN services will no longer be terminated on switches but on new boxes with new linecards called MSAN’s, & the voice data will then be carried across the new core network as IP packets as opposed to having a dedicated path in the form of a switched circuit as is the case with the legacy network.
For broadband, which already uses an IP core transport mechanism, the change is the transfer from a DSLAM box which is a Digital Subscriber Line Access Multiplexer to the MSAN box.
If that’s all double dutch, basically these 3 services will be disconnected from existing boxes, plugged into new ones which are different and then connect over a new IP core network.
Now these headline changes result in a number of network characteristic changes which we’ll go into now….

8. CPE related 21CN differences
PSTN
loop current: maximum off-hook loop current reducing.
ringing implementation moving to balanced ringing.
PSTN and ISDN
echo cancellation used unless fast modems are detected.
audio path discontinuities when jitter buffers adapt.
end to end delay increasing.
Broadband
No fundamental changes expected.
Now I won’t delve into too much technical detail unless asked to in the Q&A at the end, but
For standard analog PSTN services, there is a change in maximum off hook loop current and ringing implementation.
For both PSTN & ISDN echo cancellation is introduced on all calls and something called jitter buffers are present.
There will also be an increase in network E2E delay for these two services.
For broadband, nothing fundamental changes other than the introduction of the MSAN in replacement for the DSLAM.
These are characteristic changes that could, in theory affect CPE if it is not built to the full range of specifications and standards applied to UK landline networks.
Hence BT are driving a wide-ranging CPE testing programme.

9. Objectives of CPE compatibility testing
To help identify CPE compatibility related issues so that appropriate solutions can be communicated to all relevant stakeholders.
To help manufacturers and other stakeholders ensure that CPE functions properly on 21CN.
To help ensure that CPE compatibility related issues are constrained to an acceptable level.
Feedback into the 21CN design, if and when compatibility issues are found.
Despite it being the responsibility of equipment manufacturers to ensure that CPE functions properly on the BT network since the deregulation of the market, the objectives of having a test programme are set out here.
It is intended to unearth any issues before volume migrations commence so that they can be communicated and risks mitigated.
It is intended to build confidence and to help stakeholders assure business continuity and bust the myth that everything has to be replaced.
It also provides a feedback loop into the network design. If an issue is found, we will investigate the possibility of providing a fix in the network rather than defaulting to a CPE based fix. And more pro-actively, cpe testing has helped us define and configure jitter buffer behaviour to minimise impact on CPE.

10. Testing environments £150M investment in testing capability.
Main CPE testing sites at Adastral Park and Swansea.
BT’s CPE testing team Adastral based; isolated model; experimental build capability; second line diagnostics & investigation focused.
Swansea 8 testing bays & breakout; part of live 21CN network; supports more independent testing; supports high volume testing.
Both sites open to CPs, manufacturers, industry associations where testing is deemed relevant.
Results are published.
The CPE testing takes place at 2 sites. Bt has invested about £150M in 21CN testing platforms and the CPE testing is carried out at either Swansea or Adastral Park near Ipswich.
Both sites are open to use by CP’s, manufacturers and relevant industry associations and the only thing we ask is that if somebody uses our facilities they supply us with the test results for publication.
The main differences between the two sites are that Swansea forms part of the live 21CN network and so calls can be made to and from the site to anywhere else such as a receiving centre or external host and Swansea is built to support high volumes of testing with 8 independent test bays which can be configured as required. There is on-site support for the environment but testing done here tends to be done by the visiting third party.
At Adastral, which is where Paul’s team are based the test environment is an isolated model with no break out. Here we can change configurations and load experimental builds safe from the live network to support more detailed diagnostic and investigative testing. Here we can also get earlier access to 21CN builds and services. Adastral testing tends to be more of a second line test environment to analyse any problems found at Swansea, early access testing or regression testing. Testing here is usually conducted either by or with more hands on support from BT.
Whilst testing doesn’t guarantee operation under all conditions, it gives a level of confidence prior to migration.

11. PSTN Test Result commentary
Testing to date has confirmed that where equipment complies with the full range of specifications and guidelines in the UK Transmission Plan and BT Supplier Information Notes (both in the public domain), it is compatible with 21CN.
The vast majority of kit works on 21CN.
Some issues have been identified with equipment and data signalling protocols used by some telecare and security devices that do not fully conform to these published specifications.
The root cause of failure for these is that the signalling protocol and equipment combinations do not communicate successfully at levels of E2E network delay below the guideline maximums specified in the UK Transmission Plan (NICC document ND1701).
Such devices are vulnerable to E2E delays already encountered under existing network conditions.
With exception of Monarch, only other issue is with echo cancellers affecting some telemetry & ATMs. Network fix being pursued with vendors.
So now lets take a look at what testing have shown us in the PSTN space.
Well, the vast majority of kit works. In fact no significant failures with any devices we would describe as volume equipment such as phones and faxes.
Where we have found incompatibilities is in the telecare and security space and it is the result of the kit not conforming to standards, specifically being sensitive to low levels of network delay well below the guidelines laid out in the UK Transmission plan and the industries affected are already having problems with some other operator networks and complex call routes before we even introduce 21CN.
It remains the responsibility of suppliers/manufacturers to ensure conformity of CPE with relevant standards and published interfaces. Communications providers like BT cannot control the design and manufacture of CPE by third parties, and so cannot be liable for apparatus which does not conform to such standards and interfaces. BT is working with customers and other stakeholders to identify or validate equipment which may be incompatible and where possible, will collaborate with suppliers and manufacturers to identify the most appropriate corrective action where incompatibility is confirmed.
BT cannot unilaterally test some of the more complex devices – for some categories of equipment it is the responsibility of the manufacturers and users to assure compatibility by attending test environments with representative configurations, particularly where data receiving centres are required for application testing. This is facilitated by my CPE engagement team.
Apart from the isolated Monarch PBX issue, the only other area of incompatibility is with echo cancellers where a few telemetry devices have issues as do some ATM’s under certain conditions loss >9dB (5km+).
Network fixes are being sought for these issues and we are currently testing a fix for the telemetry devices which appears to work.

12. ISDN/ADSL Testing progress
ISDN testing has just begun with digital PBXs on ISDN30e. 5 PBX’s thus far have been tested with positive results.
ISDN testing will accelerate next calendar year with service availability at Swansea.
ADSL representative sample testing is complete with no issues found.
ISDN testing has recently begun with PBX manufacturers visiting Adastral Park with digital units to test on ISDN30e.
Early stages but everything passes tests so far.
In the ADSL space, as we predicted, because of the nature of the migration – just one IP network to another – no issues have been found in test. We have tested a range of ADSL modem and modem routers selected to ensure that we covered all of the major chipsets available today. They all work fine.

13.
This is a screenshot of our internal test database which is the primary repositary for test results – access to this is available to all CP customers of BTW and testing partners such as manufacturers and industry associations.
The URL is at the top of the page there and the database requires a logon and password which needs to be applied for.
The database provides a wealth of information on CPE testing and all of this is shared with the carrier community through whom the information can be disseminated to their respective resellers.
A lot of this information is very technical and would only serve to confuse the non-technical or non-network aware. For example, you might be able to see from this screenshot that test results are not just binary passes or fails. There are in fact 5 potential results all of which might mean different things for different categories of equipment.

14. Results key Key: Pass Pass 1 (User perception affected)
Key:
Pass
Pass 1 (User perception affected)
Pass 2 (User operation affected)
Partial Fail (Some functionality lost or delay sensitive)
Fail (Service lost)
Eg. Altered ringing cadence
Eg. Switch to tone dialling
And I’ll just briefly explain these now
A straight pass means the device works exactly the same on 21CN as it does on 20cn.
Pass 1’s means the user may notice something – eg. Altered ringing cadence, but the device is still fully functional with no user intervention.
Pass 2’s means the device is still fully functional but the user may have to do something – eg. We’ve found one phone that if it has no batteries in, isn’t connected to the mains and is switched to pulse dialling, the user can’t dial out. BUT if the phone is switched to tone dialling everything is fine.
Partial fails – most of these are where devices work on the test model, but when tested for sensitivity to network delay, they fail before getting to a round trip delay of 300ms, which is the upper threshold of the UK Transmission plan and that’s what we test to for a high level of confidence.
Fails are where the devices just simply do not work.
Eg. Works in test, but fails at delays < 300ms

15.
So that’s the test results database, but we also publish a simplified set of results in the public domain on the switched on website with the URL at the top there.
Here we simply translate pass, pass 1 and pass 2’s to a green ok to migrate.
Partial fails to an amber
Fails to a red.
A simple traffic light system intended for end users and others just to see if there is a problem with a device and then get advice from their supplier.
Also – as you may be able to see from this slide, some manufacturers have declared some items as “red” on the basis that the equipment is no longer supported or maintained. This is not necessarily simply to drive a need for replacement, but in some instances the kit is so old that there is no clarity around software or firmware revisions that may be in the installed base and so a test may not be representative of the devices an end user may still have.

16. Engagement model
Reporting back into Consult21.
Publication of test results.
CPE related policies & processes.
Incompatibility resolution.
Test partner kept abreast of public domain updates.
CPE RFI response.
Risk mitigation.
Etc etc ….
CP’s
BSIA – British Security Industry Association (Security systems)
ENA – Energy Networks Association (Gas & Electricity)
WITS – Water Industry Telemetry Standards (Water Industry)
Environment Agency
Link Network (ATMs)
Home Office – specifically custodial services (Tagging devices)
APACS – UK Payments Association (EPOS/EFTPOS)
Payphones
CAA/NATS – Civil Aviation Authority & National Air Traffic Services
Trinity House – lighthouses, coastguard
Network Rail (Railside emergency phones, signalling etc)
Lifts & Emergency Phones
Fire Industry Association
TSA – Telecare Services Association (Social & Telecare for the vulnerable)
Now on to external engagements. Basically it is the intention of the program to perform representative testing of all CPE types prior to mass migration. Where this throws up issues, we move to more exhaustive testing regime to identify as many of the problem devices as possible.
Now, with phones, faxes and modem type equipment, we can do this unilaterally – we know what kit is out there, it is easily sourced and we know how to test it.
Where I come in, and very much on a risk based prioritisation, is on the not so obvious, not so accessible CPE where the consequences of failure could be serious and/or, where it’s impossible for us to perform a truly representative test without assistance.
Basically, we research different industry sectors, find out what kit they use on what services and in what application. If it looks as though kit may be being used for something important, we engage. The way we do that is to identify a representative body such as an industry association or a dominant player. This tends to be an efficient way of addressing all the users and manufacturers without having to pick them off one by one.
We then educate them on 21CN and why they need to test. We agree test schedules and plans that are truly representative of the field applications and then drive them through a testing program. Out of this comes a number of actions and activities, some of which are listed in the top LH corner of this slide such as process developments and other risk mitigations, but I’ll come back to some of these later. In the middle of the circle of arrows you can see what I refer to as the primary engagements we are involved in and managing at the moment in this way.
Some of these lead to secondary stakeholder management engagements as well which I’ll touch on on the next slide.

17. Communications End user Industry
Switched-on doordrop, switched-on website, via industry associations, via secondary engagements, external deck (POAP & Strategy), PF1 & Grooming deck…..
Industry
Via Consult21, Call Centre Q&As, “How to deal with CPE queries”, Backgrounder documents, BT Group Policy, C21–IM-022 “Managing CPE Compatibility”, Utilities Briefing & Escalation Route
Now in support of all of the activity we’ve described so far, there are a number of tools, processes and resources in place that I’ll go through briefly now starting with some of the comms and briefing pieces.
Firstly, in the end user domain there is a lot of CPE related content, including the test results we talked about earlier on the switched on website.
There is general advice about what we’re testing, what we have tested and what we will be testing and details of the high level findings by category. There are also Q&A’s.
On the switched on doordrop material which goes to residential users and small businesses 7 days before migration, there is reference to CPE behaviour on migration disconnection and it points users to the site for more information.
We also disseminate information via the industry associations we are working with to ensure stakeholders are kept informed and have appropriate risk mitigation strategies in place where needed. For the early trial activities we provide them with detailed information on migration dates and times and have also offered some sectors the opportunity to have critical lines groomed away from the early trial migrations. As part of the bigger stakeholder management exercise we also drive secondary engagements to ensure all stakeholders are properly informed. For example, in support of the primary engagement with the TSA, we are also talking to DoH, CSIP and PASA.
In support of the BSIA engagement, we are also talking to the NSI, SSAIB and IPCRES and so on…. These secondary engagements form part of the comms routes and have a vested interest in supporting the work we do and the outcomes.
For industry, there is a wealth of information available via Consult21 to help CP’s manage CPE issues. We’ve produced …. As per list

18. Test Failure Spreadsheet (Test D/B drop down menu CPE/Documentation/Test Reviews)
We also try and make things simple. This is a screen shot of another resource.
Every month we search the database and extract all fails and partial fails and post them in a spreadsheet available from the drop down menus on the database.
So in a couple of clicks a user gets a list of all of the real problem devices.

19. Critical CPE special treatments
How can you find out what’s on the list?
In the Customer Impact Matrix
How did we define what is Critical CPE?
By consulting with you – its now under change control within the Customer
Impact Matrix
List of Critical CPE devices:
Telecare devices
Telemetry devices
Security devices
ATM machines
EPOS/EFTPOS/PDQ equipment
Public payphones
Textphones
Digital & analogue PBXs
Emergency phones
Custodial tagging devices
Now – we also have in place some safety nets for what we refer to as critical CPE and on here you can see the current critical list.
This list of categories of devices deemed to be critical was originally consulted upon and now kept under change control within something called the customer impact matrix available from the Consult21 website.
These are essentially devices that are deemed to form part of an application that is either life and limb, public infrastructure or business critical.
For these devices there are some special processes in place which I’ll touch on now.

20. Line Regression Process
High Level Interaction Diagram OR CP
BT Operate
MCC
CPE Team
CPs Fault
Diagnosis
Process
Manage PSTN
Faults
(Openreach)
Manage Migration
Faults
(21C IN-Life Ops)
Line Regression
Approval Process
(MCC Stability)
Line Regression
Implementation
Process
(21C In-Life & OR)
Close Fault
&
Handover to
20C BAU Teams
Firstly – regression.
On the next few slides, I’ll use high level design diagrams as a back drop, but don’t intend to talk through process details, just identify them and their application.
Basically, if critical CPE, as defined earlier, fails post migration to 21cn, and incompatibility with the new network is suspected, then the serving CP can request the line to be regressed to the legacy network to restore service.
Line Re-Migration
Scheduling &
Implementation
(BTO & OR)
Perform
Root Cause Analysis
(21C CPE Team)

21. Grooming process
Industry Advised CCPE Grooming Window Closed
CPs Advised of CCPE Services regressed
CP PEW Notifica-tion
CPs Advised of CCPE Services to be Groomed
CCPE Grooming Schedule Created. CPs Identified
Alarms
Industry Advise CCPE Services for Grooming
CCPE Services Grooming
Master Record of Groomed & Regressed Services Updated
Telemetry
Care
CCPE Services Pre-Jumpering (possible further grooming pass)
CCPE Regression Schedule Created. CPs Identified
Further CCPE Services advised
Similarly, another safety net I’ve touched on earlier, the grooming process.
For the PF1 trials in S Wales, we have offered the opportunity to some industry associations for their users of critical devices to have lines excluded from the trials where 100% confidence in compatibility has not yet been achieved.
CCPE PEW Raised
CCPE Regression Schedule Updated. CPs Identified
CCPE Services Regression
Further CCPE Services advised
Blanket PEW Period M
M +
nn Hrs
11w 9w 8w 7w 4w 1w
Migration Timeline
KEY:
CCPE – Critical Customer Premise Equipment
M – Point of Migration
Comms
Groom
Regress
Industry

22. CPE diagnostic processOR CP
BT Operate
MCC
CPE Team
‘21CN In-Life Operations team’ can be contacted on at any point of time either for updates or for escalating in case of issues.
21C CPE Team
Analyse
CPE Related
Problem
Is Fault Related to
Incompatible CPE
Confirmed?
21C CPE Team
Recommend
Suitable CPE
Problem Fix
(If Applicable) 2
CPE
Diagnostic Team K C I
21C In-Life Team
Perform
Logical Line
Regression
21C In-Life Team
Perform
Post Regression
Testing K C I
21C In-Life Team
Update
Necessary OSS
Systems
21C In-Life Team
Close
Fault & Inform
Openreach
BT Operate 3
And the final pretty process picture.
Throughout the PF1 trials we are running regular fault calls and at the moment these are daily.
On any fault where CPE compatibility is a possible cause, we are doing a full root cause analysis and ensuring the suspect kit is tested.
OR Field Engineers
Perform
Physical
Jumpering
Openreach

23. For Utilities & Environment Agency
“Batphone” facility for critical public infrastructure providers
Gas, water, electricity, environment agency
Community/Supporting_Information_For_Utilities_v3.doc
Another safety net specific to GAS, Electricity, and Water supply companies and the Environment agency is a bat phone facility.
A similar facility is in place for the emergency services as well.
If the utilities find themselves dealing with an issue that could be adversely affected by a 21CN migration – eg. If we are about to migrate an exchange off which hangs some vital telemetry kit monitoring an incident in progress, they can contact BT directly and inform them of the circumstances. BT will then consider the most appropriate action to take – whether that’s a suspension of a migration or some other form of mitigation.

24. Agenda:- Pro-active external trials 21CN Programme update
CPE Implications
Testing & result publication
Manufacturer/Industry Association engagement
Internal/external operational readiness monitoring
End user comms
Industry comms
Test failure spreadsheet
Critical CPE special treatments
Line reversion process
Grooming process
CPE diagnostic process
Escalation route for utilities & environment agency
Pro-active external trials
PF+ learning objectives
RFI process
So now to briefly cover off the last few items of our agenda.
We are also taking advantage of the early migrations by running pro-active trials with external industries to test the effectiveness of our own processes and methodologies, those of the CP’s and those of the external industries themselves.
For example we’ll be looking at how standard maintenance checks on certain CPE items might be modified to include 21CN compatibility checks.
We’ll be conducting a limited number of migrations by appointment to closely monitor the impact of migration on some kit and how it interacts with a host receiving centre, we’ll also test the effectiveness of some of the safety net procedures.

25. Agenda:- PF+ learning objectives 21CN Programme update
CPE Implications
Testing & result publication
Manufacturer/Industry Association engagement
Internal/external operational readiness monitoring
End user comms
Industry comms
Test failure spreadsheet
Critical CPE special treatments
Line reversion process
Grooming process
CPE diagnostic process
Escalation route for utilities & environment agency
Pro-active external trials
PF+ learning objectives
RFI process
We have also established some PF+ learning objectives where we will be working with some of our audiences to leverage the relationships to make sure we understand any special corporate and critical customer needs which will give us a gap analysis between whats in place now and what the customers may wish to be in place to assure a smooth migration.

26. Agenda:- RFI process cpe21@bt.com 21CN Programme update
CPE Implications
Testing & result publication
Manufacturer/Industry Association engagement
Internal/external operational readiness monitoring
End user comms
Industry comms
Test failure spreadsheet
Critical CPE special treatments
Line reversion process
Grooming process
CPE diagnostic process
Escalation route for utilities & environment agency
Pro-active external trials
PF+ learning objectives
RFI process
And finally, if there are any concerns or questions regarding CPE and 21CN where the answer can’t be found in the sources I’ve described so far, there is an industrialised CPE RFI process that anybody can use by ing the address highlighted here.

27. Summary Significant investment in CPE testing.
Vast majority of CPE compatible.
Testing underpinned by external consultation.
Test results available.
Compatibility issues being managed.
Mitigations in place to protect customer experience.
Bt has invested very heavily in CPE testing capability and extensive testing to date has confirmed that the vast majority of kit will work fine post migration. In fact not a single item of the volume type equipment used in business and the home has been found to fail.
We have consulted with industry and with many external organisations to ensure that proper, representative testing is being executed.
The results of the testing have been made available.
There are some devices that as a result of non-conformance to standards may have an issue on 21CN. These are being dealt with via the relevant industry associations and manufacturers.
Special processes and safety nets are in place for any CPE on our critical list to protect the customer experience and there is a wealth of information available to enable our industry to manage any CPE related queries or issues.

28. Useful information & how to get engaged
More information? then contact
Or visit these sites
The CPE testing database:
The Consult21 website:
The independent public information website covering the process of migration:
For general information about BT’s 21CN programme go to:
So before we move to the Q&A,I’ll let you look at this slide which identifies the sources of the tools and information I’ve described in this presentation.
Thank you.

29. Questions 
Answers 29