What is SIP Trunking?
SIP stands for Session Initiation Protocol and entails sending unified communications services across the internet, meaning SIP Trunking is the consolidation of multiple branches, or channels, of individual SIP sessions.
Trunking multiple SIP sessions is accomplished through another technology called IP-enabled PBX (Private Branch Exchange), which is essentially a private phone network that expands on the phone-system features that matter to businesses most.
SIP trunks running on PBX networks are basically virtual phone lines that enable users to make and receive phone calls over the internet to anyone in the world with a phone number. SIP trunks utilize a packet switch network, in which voice calls are broken down into digital packets and sent across a network to the final destination.
Before SIP became a popular and reliable method of transmitting voice signals, the Public Switched Telephone Network (PSTN) carried all telephone calls. The PSTN is the network that has those copper phone lines we traditionally associate with the "telephone." The PSTN is a circuit-switched network, which requires a physical connection between two points to complete a call.
In contrast, each SIP trunk supports multiple SIP channels (a SIP channel being equivalent to one incoming or outgoing call). The number of different channels that a SIP trunk can contain is unlimited, so your business only needs one SIP trunk, no matter how many concurrent calls you expect. The number of channels required depends on how many calls your business will make at any one time.
Phone & Data Cabling – Before
Phone & Data Cabling – After