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SIP Trunks


SIP trunking is a standards-based replacement for traditional ISDN. It connects your PBX to the PSTN via broadband, ethernet or private circuit into the national network and offers a more flexible and lower cost alternative to ISDN for inbound and outbound voice calls.

Compared to ISDN our SIP trunking solution is less costly per channel and more flexible in how and where geographic telephone numbers can be used. It is 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.

Our SIP trunk solution works seamlessly with each of the leading IP PBX phone system providers. Any business can immediately benefit from a more flexible, less expensive and more resilient phone service.


Save money

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

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


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

Business continuity

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

Don’t have a PBX? Why not consider our Business Phone System?

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  • How many people are on the phone at the same time during your busiest hours? – This will determine how many channels you will need. Remember, SIP trunks allow for quick and easy scaling, so you may add or remove channels as needed if you under or overestimate
  • Will your call volume remain consistent from week to week, or will it fluctuate? - With SIP Trunking, you can either purchase by the channel or by the minute
  • Will you need to scale or add new users relatively quickly? - This is an important factor, particularly when deciding between on-premises and hosted phone systems

Network considerations that must be examined include total available bandwidth, Quality of Service (QoS), and firewalls. Upgrading your Internet connection may be necessary to ensure sufficient bandwidth to carry a new phone system on top of typical Internet usage for your company.

Use the following simple equation to determine the necessary bandwidth to support your calls:

See how SIP trunking can save you money and improve your business

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