SIP Trunking

Replacing traditional telephone lines with a SIP trunking solution saves money without compromising on quality.

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More communication, less cost

Traditional phone lines are expensive. Replacing them with our SIP trunk solution provides you with a flexible, robust and cost-effective alternative for voice and video communications. Because we have total ownership, visibility and control of our SIP infrastructure, we have complete confidence in delivering an outstanding service, every day, 365 days a year.

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Why is SIP trunking better?

SIP works by connecting your PBX to the PSTN via your internet connection, whether that be broadband, Ethernet or private circuits. It’s hooked up into our own highly resilient network, assuring you of excellent call quality, 100% of the time.

With a solid understanding of the necessary protocols, we have configured our network specifically around VoIP traffic. We have excellent commercial relationships with numerous established upstream carriers to connect you and your customers together, wherever you are in the world.

Find out all you need to know about SIP with our easy FAQ guide.


Added benefits to your business

  • The option of free SIP to SIP calls between your sites
  • An entirely scalable solution to cater for seasonality and growth
  • No change to your existing numbers
  • New numbers can be allocated without DDI rental charges
  • Super-fast and easy to set up
  • Protected with re-route options in event of a disaster
  • Much cheaper than traditional telephone line rental

How do our Collaboration Experiences work?

All of our Collaboration Experiences are connected to PSTN services by our SIPLink product.  This provides SIP trunks that are used for voice calls by establishing an IP connection to the PSTN via our network.

Node4 SIPLink uses SIP (Session Initiation Protocol) to enable users from inside and outside of your business to make and receive telephone calls over an IP connection. Our SIP platform is based on a cluster of Session Border Controllers (SBCs), housed in multiple locations in our state-of-the-art data centres, providing a high level of security, resiliency and reliability. Through our SIPLink service, we can supply, provision or port UK geographic, UK non-geographic or international numbers, and we hold a stock of the majority of numbers for quick and easy provisioning.

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