10:48 17 May 2017
BT are to remove support for ISDN (Integrated Services Digital Network) lines and by 2025 are proposing that all customers with current ISDN technology are moved to an IP network.
With some 3 million ISDN lines throughout the UK this will mean businesses will need to look forward to ensure business continuity and either revert backwards on to a copper line solution or move forwards to a fully fledged SIP service.
SIP trunking enables you to use data to bear your outbound and inbound calls instead of using fixed copper lines. This has some inherent advantages for businesses.
1) Flexibility – Using a SIP solution your workforce can hot desk, work from home, easily add or remove lines at the touch of a button giving you much more control of capacity and cost
2) Cost – SIP can save you around 50% vs ISDN on line rental and as much as 30% on the calls themselves.
3) Number Portability – SIP allows you to access your personal phone number or DDI’s wherever you are, as the number is attached to an IP address and not a physical line.
OFCOM Say (source Ofcom)
“We believe that over the next few years including the period covered by the next Narrowband Market Review that both products will be subject to greater levels of substitution. We have included voice of the customer input from CP customers and Analysts gathered via market insight within the relevant sections and collected them within Annex A and B. In summary, we consider that the recent moves in the market have been significant enough to thoroughly examine the market definition of each product and that the criteria for Significant Market Power (SMP) be re-evaluated to take account of these changes.
In the 2014 Statement Ofcom looked at both demand and supply-side factors to consider whether the wholesale and retail price of ISDN2 and ISDN30 was constrained by potential substitutes. It concluded that a market definition based only on ISDN30 and ISDN2 exchange lines at retail and wholesale levels remained appropriate. It acknowledged IP-based services such as SIP Trunking were growing and becoming increasingly important, but considered in 2013 that these did not yet pose a sufficiently strong constraint on the supply of ISDN30/ISDN2 to warrant inclusion in the market. They summarised that demand and supply-side substitution was limited to IP Telephony products and that as SIP Trunking uses a PBX based at the customer site, it is a closer functional substitute for ISDN30 than ISDN2. We have summarised the options for substitution below, with only Hosted VoIP/IP Centrex and Openreach – In Confidence May contain Openreach Commercial or Customer Commercial Information Page 4 of 18 Openreach – In Confidence SIP Trunking being realistic alternatives to ISDN30. Broadband and IP Based Telephony are the main substitutional options for ISDN2. ISDN30/ISDN2 Leased Lines ISDN2/ISDN30 For all 3 Ofcom determined that the risk of substitution with ISDN30/ISDN2 was negligible Analogue Exchange Lines Broadband – To substitute ISDN2 In areas where broadband access is poor IP-Based Telephony –
Hosted VoIP/IP Centrex (services provided to small sites that are accessed via an ordinary broadband internet connection)
Hosted VoIP would only be a substitute for businesses prepared to use a managed network based service for PBX functionality as an alternative to an onsite PBX
SIP Trunking is generally multi-line, providing exchange line services to modern IP PBXs supporting this type of interface and is an alternative to ISDN30
SIP Trunking uses PBX at the customer site, it is a closer functional substitute for ISDN30 than Hosted VoIP services”
“We believe that this is the first step towards the UK moving away from our antiquated copper based network completely. In order to compete on speed and stability we must move away from the Victorian copper technology that has held us back for so long. By 2025 not only will businesses be running SIP instead of ISDN, but we expect this trend to be followed in the residential sector as fibre to the premises and increased bandwidth from optic networks increase.”