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BT to switch off ISDN network in 2025.

In 2015 BT announced their intention to switch off the ISDN network by 2025, but what is replacing it and why?

ISDN lines, the stalwart of UK offices across the country for decades have been in decline for some time and hundreds of thousands of ISDN lines are currently being replaced with either SIP Trunks for SIP-enabled, on-premise phone systems or hosted business phone systems, a cloud-based IP telephony solution which requires little or no hardware on site. The ISDN replacement services have one thing in common; neither use the traditional fixed line infrastructure, instead they use an Internet connection to carry the call traffic to and from the customer’s premises using a communications protocol called Session Initiation Protocol (SIP). Over the past few years the decline of ISDN services has gained momentum as businesses have benefited from improved broadband options and lower costs over time, which has given customers more confidence to adopt next generation telephony and cloud services without sacrificing the quality and reliability that ISDN has provided to the UK business market. SIP Trunks have become the leading next-generation communications solution for UK businesses and the market will continue to grow at a rapid rate, especially since BT’s announcement that they will switch off their ISDN network in 2025. SIP trunk services allow businesses to operate more freely by providing superior telephone numbering and call routing options as well as disaster recovery capabilities that ISDN cannot deliver.

  • SIP Trunk line rental is by far better value than ISDN.
  • SIP Trunks and Hosted Business Phone Systems offer far greater flexibility than ISDN as your phone numbers are not tied to a BT exchange so you won’t lose your numbers or pay expensive BT remote call forwarding charges if you move.
  • ISDN is limited to 30 channels per bearer and if you need more channels, you need to install additional bearers at great expense. SIP Trunks offer greater flexibility as you can add as many channels as you need at low cost subject to bandwidth availability.
  • SIP Trunks and Hosted Business Phone Systems also offer comprehensive and cost-effective Disaster Recovery options that ISDN cannot match.

Yet many businesses remain reluctant to make the move to SIP trunk services and the main reasons for making do with traditional services include lack of in-house skills to manage the change, concerns regarding reliability and cost. Whilst these concerns may have had some merit 10 years ago, SIP trunks services are now mature and combined with the right connectivity, incredibly reliable as well.

Convergence Opportunity

One of the great benefits of adopting a SIP trunk service or hosted telephony is that customers can use their existing internet connection to carry the voice traffic and upgrade their telephony with little disruption to day-to-day operations. This allows businesses to converge voice and data and remove traditional line rental charges. The next generation voice services are also designed with business continuity in mind and SIP Trunk resilient design builds for example allow you to route calls automatically to alternative telephone numbers or sites in the event of an outage, making it far easier to cope when things do go wrong very occasionally. Long gone are the days when you need to call your service provider to invoke a temporary call divert which might take several hours to action depending on where your business is in the queue of routing changes required on any particular day.

Peace of Mind

SIP trunks hosted phone systems can be combined with cost-effective, high performance Internet services such as EFM, FTTC and Fibre Ethernet to provide very reliable services backed by comprehensive service level agreements and automated continuity services to give businesses peace of mind and allowing them to concentrate on core competencies.

Scalability and Flexibility

Traditional ISDN lines are too restrictive in many cases. For instance if you move office you cannot retain your telephone numbers if you move out of the local telephone exchange areas as the numbers are tied to the exchange. This means either losing your telephone numbers or paying expensive remote call forwarding charges. None of this occurs with either SIP trunks or hosted phone systems as the telephone numbers are managed at network level, meaning if you move your telephone numbers can go with you. Furthermore SIP trunks services provide scalability, allowing you to start with a small allocation (just 2 channels compared to 8 with ISDN30) and scale up easily as you grow. Equally during quieter times and demand is slow, it’s easy to scale back the number of channels you use, thereby ensuring you only ever use and pay for what you actually need. Next generation voice services are also very flexible when it comes to telephone numbering. You could for instance operate telephone number ranges in Leeds, London, Glasgow and Manchester and have all calls routed to a single site allowing you to advertise local numbers without the expense of operating offices in every city.

SIP Trunk Cost Savings

The consolidation of voice and data can result in major customer savings. SIP trunk services remove the requirement for traditional lines and SIP trunk rental usually results in a rental saving of 50% or more compared to ISDN. Calls are also considerably cheaper on SIP trunk services compared to their traditional conterparts as well. When the above cost savings are combined with the built-in disaster recovery and automated call routing options, telephone numbering flexibility, scalability and above all business grade reliability it’s easy to see why SIP trunk sales have overtaken traditional line sales at Columbus and many other service providers besides. If you have not considered next generation voice services such as SIP trunks and Hosted Phone Systems before why not speak to a Columbus expert who will be happy to review your current set up and provide straightforward recommendations whether you are ready to move to next generation services now or whenever the time is right for your business.

Download the Columbus SIP Trunks Brochure