What is SIP Trunking?

SIP Trunking is our standards based replacement for traditional ISDN. It connects your PBX to the PSTN via broadband, Ethernet or private circuit into a national network. Our SIP Trunks work seamlessly with each of the leading IP PBX brands in the UK market.

Compared to ISDN our SIP trunking service is less costly per channel and more flexible in how and where geographic telephone numbers can be used. It’s also quicker to install and provision and, as standard, it delivers extremely robust business continuity.

The service can support connections ranging from two channels for small PBX-equipped businesses to an unlimited number of channels for large enterprises and contact centres.

  • Save money on call costs and line rental

SIP delivers less costly, more reliable connectivity than ISDN over an IP connection. It can save up to 50% on line rentals and 25% or more on call costs. 

  • Free internal calls and great features

Perfect for medium or large organisations with multiple sites, not only will you save on your line rental and call costs, but you’ll get free internal calls within your organisation and a whole host of great features.

  • Scale up and down when you want

SIP trunks are ideal if you are moving, upsizing or downsizing and want to keep your existing numbers. Scale up lines during busy periods and back down again afterwards. You can add lines, take them away, split calls at any time. You are always in control.

  • Built-in Business Continuity

SIP trunks can handle emergencies easily. They are inherently disaster recovery / business continuity ready, letting you reroute calls to an alternative location quickly and easily. 

Can I have SIP Trunking in my business?

Any business with a PBX can switch to our SIP trunking service and immediately benefit from a more flexible, less expensive and more resilient phone service. Try our SIP v ISDN cost calculator right now and see for yourself. Don’t have a PBX? Consider our Hosted Horizon phone (more details below).

How resilient is SIP?

SIP trunking is now a mature service enjoyed by thousands of UK organisations and this alone is testimony to the reliability of SIP. For added reassurance while you switch to us, SIP trunking can even be used with existing ISDN connections to ensure the transition goes smoothly.

Business continuity

SIP Trunking can help to minimise disruption to your business. An essential element of any Business Continuity Plan would be to ensure that your phone lines are re-routed to other offices. At no extra charge to you Call Networks can route calls from one office to another in cases of natural disaster or other emergencies.

Multi-site rationalisation

If your business has multiple sites with ISDN connections into each, using our SIP Trunks you can reduce the number of ISDN connections that your business requires and also reduce the maintenance costs on all of your various PBXs.

At the remote sites you are left with just the cost of an IP connection and the handsets that you need and you can then pull all the telephony traffic back into your centralised PBX. 

Moving office

Number flexibility with SIP trunking means that you can keep your existing number, even when moving out of the area, saving you costs on printed company literature and stationery whilst maintaining the perception that you still have a presence in the area you’ve moved from.

We can easily transfer your old or existing numbers too so that you can avoid expensive Remote Call Forwarding (RCF) or call diversion charges.

Flexible number display

Decide which number you want to display on a call by call basis! Great for contact centres. Use CLI flexibility to present your preferred number on your outbound SIP trunk calls.

Want to know more?

Call us on 0800 160 1920 to discuss your options. We’re here to help you make the right decision for your organisation.