What is SIP Trunking?

Session Initiation Protocol (SIP) Trunking is a way to connect your business telephone system to the Public Telephone Network (PSTN) so you can make and receive calls. Unlike a normal telephone line or ISDN, SIP Trunks use a normal business grade internet connection and are managed by a company who will act as a SIP provider.

SIP is part of a wider suite of technologies that were designed in the 1990’s to facilitate the transmission of multimedia over the internet. Around 2007 SIP started to be used as a way to allow telephony systems to use the internet to make and receive calls. This use of the internet for making and receiving calls has, as we’ll see, a number of potential business benefits over ISDN. In addition to this, the benefits of SIP Trunks over ISDN lines have continued to grow and improve.

SIP Trunking architecture

What Type of Business can use SIP?

SIP technology has seen a large year on year rise in its usage. 26.6% growth in 2012 and 17.1% in the first half of 2013 with the last half of 2013 seeing the total number of SIP trunks surpass 1 million. This surge in growth has seen all types of businesses, from small start-ups and SMEs to large corporations adopting SIP Trunking.

As high quality fibre-based internet access becomes accessible to more and more businesses the SIP marketplace is beginning to show its full potential. Because of the way SIP uses the internet to transfer traffic, it can offer enhanced flexibility to businesses while offering substantial cost savings over traditional ISDN connections.

What are the Benefits of SIP Trunking?

  • SIP is accessible

SIP trunks and the number and type of telephone numbers they handle can be increased and decreased quickly and easily. If your business experiences seasonal ups and downs with inbound and outbound calls then SIP can often prove very useful.

  • SIP can be easily reconfigured

Because SIP trunks are handled by a SIP provider, both geographical and non-geographical telephone numbers can be routed to wherever you wish. Adding, removing and repointing DDIs can also be done easily.

  • SIP is cost effective

Often ISDN line rental costs can be higher than using SIP trunks. Combined with savings in management fees, phone charges and increased efficiency, SIP can often bring your telephony costs down over time.

  • SIP Improves your Business Continuity

Because your SIP provider is a third party, your business premises being fully operational is no longer a single point of failure. Should the worst happen and your business site be down for any reason, your numbers and calls can be rerouted and DDIs repointed instantly.

  • SIP is secure

As with all internet technologies, steps must be taken to secure your SIP infrastructure. Well managed firewalls and ensuring your SIP systems are correctly configured will protect your business for security breaches. In addition to this, some SIP providers provide network level monitoring to further reduce any possibility of a security breach or unwanted call charges.