Bridge the gap between legacy & cutting-edge business communications systems

SIP trunks are on-premise solutions that connect your existing telephone networks to the PSTN (public telephone network) through internet cabling, enabling organisations to make and take calls over the internet rather than making use of legacy ISDN systems.

With BT’s ISDN and PSTN switch-off set for 2025 and the selling of any systems using these technologies due to end in 2020, the clock is ticking for traditional legacy solutions. A SIP Trunk can connect to existing PSTN lines as well as more modern cloud-based solutions, which will be the norm in just a few years.

If your business is using ISDN or PSTN systems, now is the time to set the wheels in motion for smart IP technology to be introduced into your workplace.

Allowing businesses to make use of IP handsets, VoIP systems, unified communications, conferencing, remote working, call recording and much more, the performance and feature benefits available with a SIP trunk are numerous.

What’s more, setting up and maintaining such a system is far simpler than a traditional solution, while users can be added or removed just as easily.


Quickly and simply add or reduce the number of trunks you require, depending on demand and capacity


With clear and transparent pricing, SIP Trunking is cheaper than traditional ISDN lines

Ideal for
Multiple Sites

SIP Trunking allows you to reduce the number of required connections, hardware and handset across different sites

& Adaptable

Should a disaster or unplanned outage occur, easily move or divert calls to any location

Our Approach

With over 150 years of combined experience, our expert team will listen carefully to your needs and work with you to design and implement an efficient, integrated bespoke solution.


We assess your entire IT infrastructure, identifying opportunities for strategic cost reduction.


We work with you to design a ‘best-fit’ hardware and software solution.


Mitigating risks and minimising disruptions, we smooth the ‘digital-first’ transition.


Our support packages offer complete peace of mind, allowing you to focus on your business whilst we take care of your technology.


As your company changes over time, so can your telecom needs. Our future-proof solutions ensure your technology can scale along with your business.

More Services From DMC Technologies

Cloud-based communications that improve performance and flexibility.

Advanced analogue solutions which deliver high performance.

Bespoke, flexible and integrated communications services.

Advanced connectivity, suitable for modern communications systems.

Request a call back

DMC Technologies are committed to delivering more for our customers.


Get in touch today to discover how cloud technologies create competitive advantage. Simply complete your details and one of our experienced team will contact you within 24 working hours.


Should you require assistance in the meantime, please call us on 01233 527 100.

020 8688 4243