How Does SIP Trunking Work?

SIP TrunkingThe biggest difference between SIP Trunking and traditional telecommunications is that SIP connects your Business Phone System to the outside world through the internet and VoIP rather than physical phone lines. SIP Trunks can also relay video and messages. They are now seen as a very common and popular way for companies to carry out their business communications.

However, there is a lot more to it than that. Here’s what else you need to know:

Session Initiation Protocol

SIP is also known as ‘Session Initiation Protocol’. In technical terms, it works by using software protocols to begin and end connections between devices. These connections relay multimedia data.


One of the biggest reasons companies should consider SIP is the cost savings. Oftentimes, companies save as much as 40-50% off of their monthly phone bill when compared to PSTN (analog) service. In any event, it is a good idea to think of the future. Analog phones are being phased out, and before long it will get more difficult to find technicians to work on your system if something goes wrong.


As mentioned above, SIP Trunking operates through the internet. Therefore, it is important to know how much bandwidth you will need if you switch. While it varies, a rough estimate of any one active SIP call is about 64k/s. This is not very high. It is much more realistic to expect the limitation to depend on how many channel licenses you have. It is important to work with a provider who understands the technical details as well as your organization’s infrastructure.

SIP Trunk vs. SIP Channel

Each SIP Trunk connects one location to the outside world. SIP channels on the other hand, are within the trunk and determine how many calls you can place at once. You’ll find that you typically need less channels than extensions, as all of them won’t be in use at once.

One of the great benefits of SIP is that you can change the number of SIP channels you have without changing your hardware. It is simply a matter of licensing and bandwidth.

If you have any questions regarding SIP Trunking, please contact Intuity today at (800) 811-1086. Please feel free to also follow us on Facebook.