Understanding the basics
SIP refers to Session Initiation Protocol. This is a form of VoIP (Voice over Internet Protocol). The Trunk part of this equation relates to the lines that connect users, even though real wires are not present. In this case, SIP trunks can provide a bridge between an organisation, through the Internet, to the outside world.
The standard form of telephone communication is via an ISDN phone line. When it comes to businesses, connecting to the PSTN (Public Switched Telephone Network) is a case of going through a PBX (Private Branch Exchange), whereby a company designates specific numbers and lines across employees. SIP trunks offer a more efficient alternative. Rather than using a separate network for your phone calls, SIP trunking effectively routes your calls across the Internet. Similar to how other sounds, images and documents transmitted across the Internet, SIP trunking enables voice calls to be sent in a quicker, more cost-effective fashion.
How do they work?
SIP is based on textual transmission and makes the connection between the caller and receiver. Users can also send other media, such as pictures, documents and video, making this a multi-purpose option.
Businesses can buy DID (Direct Inward Dialling) numbers and get VoIP wholesale rates from the likes of www.idtexpress.com.
Utilising SIP trunks can be done in one of two ways. Firstly, a centralised setup will see all calls inbound to one destination. However, if this SIP trunk encounters a problem, it will have a knock on effect to all lines. The second option is a decentralised setup, with individual offices having their own trunk. Any problems with one SIP trunk will not affect the others, but it may become a more costly configuration with more software and maintenance required.
The benefits of SIP trunking
VoIP is an ever-growing market, predicted to be valued at around $88 billion in 2018 – https://www.forbes.com/sites/forbesagencycouncil/2017/12/06/how-to-increase-the-accessibility-of-your-business-using-voice-communication/#768263cd5d84.
Communication over the Internet via SIP trunks means that your calls, and other media sent, are free. Long distance communication is also cheaper as these calls are routed over the PSTN. In addition, businesses can generally purchase the number of lines required, without the need to bulk buy. ERP and CRM software can also be combined and utilised alongside SIP trunks for greater effectiveness within organisations too.