SIP is a technology that delivers voice using predefined channels within a data circuit. These are known as SIP Trunks. This technology allows for the creation, modification and termination of voice sessions on an IP network without loss of quality.
SIP is an application-layer control protocol. The ‘trunk’ in SIP trunking is the channel that allows you to control telephony and keep the voice separate from data services such as instant messaging and multimedia. In essence, voice calls are converted to SIP meaning costly ISDN rentals are no longer needed and calls are delivered using VoIP.
Once you have chosen to benefit from SIP trunking, you will have dedicated lines or channels, separate to data channels and uncontended, meaning you don’t share bandwidth or suffer disrupted service when there are many users nearby.
When a phone call or multimedia action takes place, your PBX will route calls using SIP trunks to make calls via the internet. The number of calls that can be processed at any one time is dependant on the number of channels you choose to take and can be added to easily, without the need for physical lines to be installed.
With SIP trunking, outbound calls can be made locally, long distance and internationally. It may be best to think of SIP trunks as the phone wires we’re all familiar with from analogue and digital systems; they’re the connection to the internet that complement unified communications.
Once installed, the return on investment is quick and significant, with large savings in comparison to traditional PBX systems using ISDN.