21CN

What is 21CN?
What has BSIA done to assess the impact of this change?
How do I know if my equipment is at risk of failure?
What is the latest situation with the 21CN migrations?
Is the BSIA working with other Next Generation Network communication providers?

What is 21CN?
BT is upgrading its existing telephone network to a “next-generation network” (NGN). BT is using the term “21CN” for this. Some of the key facts are as follows:

The 21CN network uses a Digital Internet Protocol (IP) network.
The migration will ultimately result in 30 million PSTN / ISDN lines being transferred to 21CN, including 8 million broadband lines
This will require replacement of equipment in 5500 BT exchanges across the UK
The migration will result in wide availability of high speed broadband access, including a super fast ethernet service
21CN will provide a UK NGN platform for other comms providers

Customers will be “migrated” from the existing telephone network to 21CN lines over the coming years. Being a digital IP system, there will be some fundamental changes in the operation, which include delays in transmission of data and the effects of interconnecting other NGN providers. Both of these can impact on security equipment as the transmitted signals have a dependency on time between the communicating transmitter (the signaling device at the customers premises) and the transceiver unit (the receiver at a monitoring centre).

Other communications providers are making similar changes to their networks so you may be affected even if you do not use BT.

What has BSIA done to assess the impact of this change?
BSIA has worked closely with BT over the last few years, since the emergence of 21CN was made known to us. Through initial testing of security products on the “simulated” network, and then on a “live” 21CN network, we have been able to understand how the effects of this change can impact on equipment.

Through our manufacturers we have produced a security equipment test plan, which provides a rigorous sequence of tests that covers the various signaling formats used in the Industry. The tests are conducted at the BT test facilities In Swansea, with specialist equipment provided by BT.

The BSIA test plan can be downloaded by clicking here.

Note. The BSIA Fast Format guide has recently been reviewed as a result of 21CN and NGN activity and is now available. Previous versions of the guide are available on request. The BSIA Fast Format guide can be downloaded by clicking here.

Through the testing we have conducted to date, and the knowledge we have gained through discussions with BT, Ofcom and other comms providers, we have been able to call on a wealth of experience and develop a risk based assessment of the impact of 21CN on security equipment. This assessment evaluates the likelihood of something happening and the consequence it delivers. The output of this assessment has enabled us to provide a clearer message to end-users, installers, monitoring centres and manufacturers. BSIA members have been briefed on the risk assessment outcome. The basic advice to end-users BSIA form no. 275 can be downloaded by clicking here.

How do I know if my equipment is at risk of failure?
All BSIA comms equipment manufacturers have attended the BT facility in Swansea and tested their core products against the BSIA test plan. The results of these have been published on the BSIA website.

The test results can be downloaded by clicking here.

The test results focus on the main potential failure mode for 21CN, which is additional network delay. They also provide a 21CN compatibility test.

Reading the results on their own may not provide a straightforward answer to whether certain equipment is at risk, as there are two other factors that can affect the overall delay of alarm signals; these being the type of receiving equipment and the type of network on which it is transmitted. To assist with this, BSIA has also produced a web based “risk calculator” which allows you to enter the two fundamental values under consideration, those being the communicator delay and the receiver processing delay. Once these values are entered, a graphical representation is produced showing you the potential risk of failure on each of the known network routing configurations.

The web-based calculator is available by clicking here.

NB. Whilst every effort has been made to ensure that the results are full and reliable, the BSIA cannot accept any liability for the accuracy of the results or responsibility for any reliance upon the results. The tests which gave rise to the results were dependent upon British Telecoms technical equipment and were carried out by each contributing manufacturer themselves.

What is the latest situation with the 21CN migrations?
BT has completed its initial “Pathfinder” migration of approximately 65K PSTN lines in the Cardiff area to 21CN in Spring 2009 and was expected to announce details of the migration of a further 275K PSTN lines in the Cardiff area for later this year.

Following a recent strategic review of its NGN business, BT has announced its intention to withdraw plans to mass migrate both PSTN and ISDN lines to 21CN. Migrations to 21CN will now only be based around customer demand and exchanges where equipment is reaching the end of its life.

Whilst this change is relevant to the "voice" element of the mass migration (where the majority of comms devices operate) the broadband aspect will continue apace. BT will concentrate their drive toward fibre to the cabinet and fibre to the premises over the coming year(s), to realise a 40% coverage of high speed broadband access by 2012. The security industry needs to understand the impact fibre may have on security equipment, and to that end BSIA will once again lead the way in assessing any impact.

A statement from BT regarding the outcome of their strategic review can be downloaded by clicking here.

BT is working towards the availability of a fibre test platform at their test facilities. The BSIA is fully involved in this process and once the fibre test platform is complete, the BSIA will consider the need to produce a security industry test plan for its manufacturers to test products against. The results of these product tests will be displayed on the BSIA website.

Ofcom has recently completed its consultation, which focuses on the revisions by BT to its plans for 21CN and the concerns rasied by stakeholders. It also seeks to address NGN technology and the possible disruption it will bring, including the need to protect customers.

Is the BSIA working with other Next Generation Network communication providers?
Since the Ofcom consultation, a communication industry forum called NGNuk has been established. This forum comprises of Communication providers and Ofcom and its primary role is to address issues with NGN and NGA (Next Generation Access) across the UK. BSIA has already established a link with this forum and is addressing the needs of our members, especially around fibre access, testing and network understanding.