Supercharge your business activity with high performance voice and data services
You don’t want to be left behind in business. So, now’s the time to speed up your connection – efficiently and cost effectively – with Integrated Services Digital Network (ISDN) lines from TSI.

ISDN lines – which are available in a range of specifications, including ISDN2e and ISDN30 – are used to provide instant connections and crystal clear voice communications.

What’s the difference between ISDN2e AND ISDN30 lines?


With two lines on each ISND2e circuit, you can do two things at once – make or receive calls, or send or receive faxes, and adding additional ISDN’s increases your capacity even further.

When linked into a Digital Telephone System, ISDN2e lines are designed to provide businesses with exceptionally clear, high quality voice calls. ISDN2e can be installed with one number or multiple numbers


These lines are very similar to ISDN2e lines. The main difference is that they provide a larger number of channels, with a minimum of 8.

The future of ISDN

It’s widely reported that the ISDN network will be switched off by BT Openreach by 2025, as part of overall plans to migrate customers to a new IP network using SIP trunking.

SIP trunking is the latest form of technology that delivers telephone lines using an external data connection for making and receiving calls. In layman’s terms, SIP trunks are telephone lines on your broadband.

This virtual IP-based service uses network data connectivity instead of dedicated fixed line technology methods.

Learn more about SIP trunks

Alternatively, you could replace your onsite PBX telephone system with our cloud-based suite of Anywhere unified communications. With this approach, not only is there no need for telephone lines or SIP trunks, you’ll enjoy the benefits of a top of the range telephone system that can be used anywhere.

Learn more about Anywhere