SIP Trunking is a virtual link or connection to replace your traditional PSTN. Using a Sip Trunk you can transmit voice, data, and video over the Internet. Rather than through the Public Switched Telephone Network.
SIP trunking enables the end point’s PBX (Private Branch Exchange phone system) to send and receive calls via an IP network, such as the Internet or private WAN. As SIP is applied for the signalling protocol for multiple real-time application, SIP trunk is able to control voice, video and messaging applications. It is also a voice over Internet Protocol (VoIP) technology and streaming media service based on the Session Initiation Protocol (SIP) by which Internet telephony service providers (ITSPs) deliver telephone services and unified communications to customers equipped with SIP-based IP PBX and unified communications facilities. Most unified communications applications provide voice, video, and other streaming media applications such as desktop sharing, web conferencing, and shared whiteboard.