ISDN is being switched off. How should you replace it?

ISDN is being switched off. How should you replace it?

ISDN stands for Integrated Services Digital Network and has been around for 25 years. In the five years between 2007 and 2012 the number of ISDN channels shrank from 4.7 million to 2.7 million in the UK. The increased demand for flexibility is the main factor in this decline, and the availability of high speed Internet and mobile phones are key drivers to change and the ISDN network has struggled to keep up with these demands.

In 2016 BT confirmed the plan to put the ISDN network into retirement and migrate all its customers onto its IP Network by 2025. Businesses who want to get ahead are already exploring alternatives and many have already discovered the power of Internet based telephony. BT will stop selling systems that use ISDN by 2020 which will inevitably mean that  parts will become obsolete and trained engineers will start to be redeployed and retrained. BT have not installed any new lines in London since 2014 showing that demand has been slowly diminishing, but nearly 3 million users is still significant and moving them over will be quite a task, so if you are one of them you would do well to start the process ahead of the rush.

Replacing an ISDN System
Internet Protocol telephony services are centred on the protocol SIP, which has matured as a safe replacement for ISDN and no longer considered new technology. Here we look at the the three ISDN replacement services offered by us at Firstcom:


Cloud based VoiP (Universe)
A virtual phone system, or one that is hosted in the cloud is ideal for smaller businesses, start-ups or any organisation who does not want to invest in an expensive on-site phone system. The great thing about a hosted phone system is the complete flexibility it brings. If you move the system moves with you, and users can be quickly added as you grow. Subscription based billing means you can control monthly communications cost up front.


SIP Trunks
SIP Trunking is a solution that connects the customer site directly into the Service Provider’s network. The SIP Trunk Service can be configured to run over a simple Internet connection or a dedicated leased line.It carries and terminates inbound and outbound calls across your selected circuit type. Our SIP Trunks are designed to work with all the leading phone system brands and are a good solution for businesses who want to own their phone system and manage it in-house. Businesses who have already replaced their ISDN service with SIP are enjoying significant cost savings along with scalability, flexibility and superior disaster recovery.

SIP Encrypt
Businesses who are concerned with Information Security should consider a SIP trunk solution that offers encryption. ISDN is inherently secure as a fixed net of wires going from point to point from the customer site to the service provider’s.

SIP trunks that are configured to work over parts of the Internet that are inherently accessible to hackers. This is where SIP Encrypt comes into play. All calls, in and out, will be encrypted to a high standard, thus allowing organisations to set up and maintain a security policy conforming to the highest requirements.




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