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SIP Trunking

Achieve cost savings, increased resilience and flexibility with our SIP Trunking services.

A Lower Cost Alternative

SIP Trunking is our standards based lower cost alternative to traditional ISDN for inbound and outbound voice calls. 

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.

SIP Trunking

Standards based lower cost alternative to traditional ISDN for inbound and outbound voice calls.

Commercial Value

SIP Trunks allow customers to converge their voice and data services onto one network, so they no longer have to pay out for expensive ISDN rental costs. The cost of making Voice-over-Internet Protocol enabled telephone calls is much cheaper than over an ISDN infrastructure, especially for overseas calls. Furthermore, if a business enjoys exponential growth, SIP Trunks allow for the extra phones and channels to be added without installing extra lines at great cost.

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SIP Trunks allow for the presence of overlay features such as Mobility, Contact Centre, Call Recording and interactive voice response technology.
SIP Trunks are ideal for sales based companies, amalgamating web-based click to call into a company's website can allow customers to instantly call relevant staff to help them with their enquiries and improve employee productivity.

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Universality and Future-Proofing

There is no need to replace existing technology that is SIP enabled. If your PBX system was made in 2008 or later it will already be able to support SIP. If it can't support SIP then you will need to buy a small device called a SIP-ISDN Gateway that will act as bridge between your SIP trunk and the ISDN interface of your PBX.
By upgrading to SIP trunks now, your business will be primed to benefit from any advancement in Internet protocol (IP) voice technology and be able to integrate them into operations with the maximum of ease.
As SIP Trunks allow your business to export your existing number - even if you move premises - the end customer experience remains consistent.

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OPEX Model

SIPCOM services and hardware are provided on an OPEX model without any upfront capital expenditure. Often we can work within a customer's current monthly budget.

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24/7 Support

Our SuperSupport incident desk provides a follow the sun service globally. SuperSupport can also be made available with local language support, if required.

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International Coverage & Global Capabilities

SIPCOM's SIP Trunking Service can provide numbering in 64 countries and over 6000 cities worldwide, porting with over 50 operators.

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Local Emergency Service Support and E911

SIPCOM has developed a proprietary E911 application, which dynamically updates roaming user location details to the relevant Emergency Services database. In addition we have Emergency Service capabilities in over 20 countries.

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Bandwidth Optimised Voice Server

For those customers with limited bandwidth or budget, SIPCOM supports a variety of codec's including G711, G722, G729 allowing calls to be compressed or expanded depending on bandwidth availability.

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PBX and Platform Support

SIPCOM's SIP Trunking service is platform agnostic and can connect via gateway or directly into existing on premise or hosted platforms.

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The service is cloud–based, infinitely scalable and can support connections ranging from two channels for small PBX-equipped businesses to an unlimited number of channels for large enterprises and contact centres. It offers a simple and cost-effective way to add additional phone line capacity on demand – as and when you need more. There are many benefits to going virtual – you will incur huge cost savings compared to traditional line rental and call tariffs are much cheaper; you can also make SIP-to-SIP calls for free to anywhere in the world.

SIP Trunking is suitable for any size of business that currently has a PBX or Unified Communications solution.

Here are some typical examples of how SIP Trunking helps organisations:

  • Businesses looking to move premises out of the local area who want to keep their business critical phone number without paying for expensive call forwarding type services
  • Companies looking to have disaster recovery measures in place to provide a resilient phone service to cope with any emergency
  • International businesses linking offices and taking advantage of free internal calls from one office to another, even where the internal calls cross international boundaries
  • Customer service driven businesses where a local presence is important across the UK and multiple UK numbers can be delivered into one single service centre
  • Multi-site organisations that are looking to aggregate individual site PBXs and lines into a resilient centralised solution
  • Businesses with seasonal voice capacity requirements – where more lines for a sales campaign, for example, can be quickly and easily implemented with no long term commitments

Disaster Recovery

Ensure your business is fully protected. If your office experiences problems simply route calls to mobiles or another site remotely, and your customers won’t know the difference.

Voice and Internet Convergence

With SIP delivered over Ethernet, you can have both a high quality voice and data service all over one connection, giving you significant cost savings.

Save Money

IP connectivity reduces infrastructure spend because it costs less than ISDN with lower call costs, free internal calls between extensions and offices (including international calls) and lower line rental costs for multi sites. Also, no expensive call-forwarding costs are required should you relocate or need to divert calls in the event of a disaster. Typically, a SIP channel costs 70% less than an ISDN channel.


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 and split calls at any time.

Increased Efficiency

Consolidate your voice communications and data connection to improve the efficiency of your network and ensure you are taking advantage of your existing bandwidth capacity.

Number Flexibility

A variety of number types are available to allow you to give your business a national presence, or simply transfer your existing numbers to the SIP platform.

Compatible with Microsoft Lync 2013

Our SIP Trunks are integration tested and approved to interoperate with Microsoft® Lync 2010 and 2013™, allowing you to directly connect to the Microsoft Lync platform to make external calls.



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