The rise of SIP Trunking

As one of the most important aspects of a company’s infrastructure, it is imperative that its communications systems can support employees in their day-to-day activities. Employees need to be able to communicate with each other across offices, and even countries, and even more vital is their ability to communicate with customers.

Traditionally, voice networks have run separately to IP networks but as companies look to streamline costs, make their businesses more flexible and efficient, we have seen a greater demand for moving to a single, converged IP infrastructure. As a result, many organisations have implemented a SIP trunking service. Indeed, the last 6 months of 2013 saw the UK IP/SIP Trunking market continue to grow and it passed the one million trunk mark for the first time. SIP trunking is also listed in Gartner’s Critical Capabilities for Pan-European Network Services  report¹.

At the same time, as traditional voice line services are replaced by more mature IP telephony, many users are migrating from TDM telephony to SIP-based communications to benefit from new services such as unified communications.

Previous barriers to adoption have been primarily been cost of access (i.e. providing bandwidth to the customer site where the PBX is located), and the maturity of technology vendors that support SIP trunking. Whilst SIP is a standardised IETF protocol stack, the standards have been implemented by vendors slightly differently, and therefore service providers have had to adapt to vendor requirements by ensuring that their infrastructure can support them. Here at Colt we have carried out and proven interoperability directly with major vendors such as Cisco, Avaya, and Microsoft Lync. For non-certified PBX’s we offer dedicated engineering support, helping our customers across Europe to get any IP PBX up and running.

Maturity and trust are additional factors. ISDN TDM services have been used for over 30 years now, whereas SIP trunking has gained major market traction only as recently as 2005. Therefore customers who have used these older, more traditional services may want to keep them in order to sweat the asset investment they have made in TDM.

This issue is now being eroded by organisations’ business needs to reduce OPEX costs and improve mobility to their workforce to enhance business productivity. When completing a standard TCO analysis, the cost benefit shows that transitioning to SIP trunking is a justified investment, particularly when there is a strategy to converge voice and data networks onto a common backbone. Organisations can benefit from the cost reductions created by both consolidating the number of PSTN local access lines required and by then centralising volume purchase.

With our VoIP Access solution we helped self-storage provider Shurgard reduce recurring telephony costs by 30%, as well as helping the company to improve the way that it manages inbound calls from existing and potential customers.

There are multiple business benefits to moving to a SIP trunking service, my next blog will focus on some of those specific benefits in more detail.

¹Gartner, Critical Capabilities Report for Pan-European Network Services, Neil Rickard and Katja Rudd, 26 March 2014.