SIP trunking – the future of connectivity

12 March 2014

A SIP (Session Initiation Protocol) trunk is a connection between an organisation and an internet telephony service provider (ITSP).



What is SIP trunking?
A SIP trunk essentially removes the need for a direct connection to a public switched telephone network (PSTN) and enables the customer to facilitate VoIP calls in a much faster, simpler and less-expensive fashion. SIP trunking can therefore provide a quick and substantial return on initial investment and is becoming the unified communications method of choice for many.

As well as allowing VoIP calls, SIP trunks are also capable of delivering instant messages, multimedia conferences, data and other SIP-based, real-time communications services. As trunks become more all-encompassing, additional layers can be added to allow for more communication services to be delivered.

What are the main drivers for SIP trunking adoption?
The major driver of SIP trunking adoption is said to be its cost efficiency. Having a SIP trunk removes the need to have both a primary-rate interface (PRI) and a VoIP connection, meaning that businesses and organisations only need to pay for a connection to a SIP-enabled unit to connect to the wider network.

On top of this, it is much easier to add extra capacity to the SIP connection than it is with a PRI, which has limited bandwidth. Should a company wish to expand its capacity without a SIP trunk, the company would likely have to purchase another PRI connection to fulfil its needs. With a SIP trunk, a company would only need to expand its bandwidth on the same link, incurring a much lower cost.

Industry experts at Forrester Research estimate that companies that adopt SIP trunking over traditional TDM systems could save up to 35% in revenue following the changeover.

Disaster recovery is said to be another USP for SIP trunking, which allows a call to be redirected in the instance that a connection is lost. Additional buildings and phone lines can be added to the SIP trunk with ease and temporary locations can be connected and disconnected quickly and efficiently thanks to its ability to reroute.

Which carriers are pioneering SIP trunking?
In December last year, Colt extended its SIP trunking offering – Colt VoIP Access – to focus on the disaster-recovery aspect of the service.

The European operator implemented advanced security functions to allow customers in the region to more easily secure their VoIP traffic.

The upgraded service is designed to protect against attacks such as eavesdropping and interception, and offers online analysis of traffic, performance and network utilisation, as well the ability to generate call-monitoring reports.

Customers are said to be looking for more secure unified communications and Marta Muñoz Méndez-Villamil, research director, telecommunications at IDC EMEA, believes SIP trunking holds the answer.

"Increasingly, customers who are seeking an enhanced voice provider require guarantees that their business-critical and back-office functions can be ably supported by their SIP trunking or VoIP service provider," Méndez-Villamil says. "Colt’s solutions and their cross-Europe capabilities mean that multi-branch offices can expect the same service, no matter where they operate."

Earlier last year, US operator Sprint recognised the growing demand for SIP trunking and rolled out its solution in 12 European countries, including Austria, Belgium, Denmark, France, Germany, Ireland, Italy, Netherlands, Spain, Sweden, Switzerland and the UK.

Tim Donahue – VP of solutions and international sales at Sprint – highlighted flexibility and scalability as the key advantages of SIP trunking and believes it is a technology which is only set to grow over the coming years.

"We are pleased to extend these benefits to businesses with operations in Europe," he says.

What is the future for SIP trunking?
A study from telecoms company XO Communications estimated that by 2016, 92.7% of phone lines will be SIP-based.

Industry expert Michael Cavanaugh believes that SIP will open up a much wider pool of unified communications services. Video calls and conferences via SIP trunking are starting to be implemented around the globe and this service is only set to become more streamlined and more efficient.

With much SIP trunking activity occurring in Europe, US cable provider Comcast is looking to give the service more of a presence in the US in 2014.

At a conference in New York in December last year, John Guillaume, VP of product management and strategy at Comcast said that its SIP trunking trials had been running very well.

It plans to roll out the service nationwide by the end of 2014, which will not only focus on SMEs but also larger businesses.

"SIP is the natural next stepping stone to complete [Comcast’s] portfolio; 85% of the market is still PRI, but SIP is at 15% and growing fast, instead of being a declining market," Guillaume says.

Topics: SIP, trunking, ITSP, connectivity, PSTN, Colt, IDC, Sprint, VoIP