A SIP trunk can be thought of as a virtual ISDN. It's the connection made between your phone system and the outside world, but delivered over the internet and far more flexible than an ISDN line.
You might already know that BT Openreach are turning off the ISDN network in 2025 (more details can be found here), pushing all users towards VoIP services. This could mean a big upheaval for a lot of businesses. Some businesses might not be in a position to think about new telephone systems, or migrating to a hosted VoIP solution. But fear not, there are plenty of options available to you...
Typically for use with on-premises systems, whether they are old legacy systems or new native SIP systems, a SIP trunk can be implemented with relative ease. The migration process takes over all of your numbers and presents them through the internet in the form of a SIP trunk which your SIP telephone system will be able to accept, an older legacy system might need a gateway to convert it from SIP into a form of ISDN presentation. We can work with your existing system maintainer to ensure compatibility.
You don't need to do anything. We can manage the migration process, keeping you informed of key dates along the way. It's important to remember that these circuits are delivered over the internet, so space in your comms room will be required, but we will outline all of the requirements beforhand so there are no surprises.
COST! The most important benefit of all. SIP trunks are significantly cheaper that ISDN lines per channel. They are also far more flexible, allowing you to increase or decrease the amount of channels based on demand. ISDN is limited to only 30 channels per circuit and the installation costs are very high.
The ISDN network is going soon, so by adopting relatively early you will beat the inevitable rush as the deadline draws nearer.
SIP trunks also have an element of disaster recovery built in. It's possible to divert individual DDI numbers, or entire ranges, in the event of a total service failure. If the power to your building gets knocked out, divert the lines to people's mobiles, other offices, or telephone answering services at the click of a button.