SIP trunking is used by many organisations, it allows a business phone system to work over an internet connection as opposed to legacy systems and traditional telephone landlines. There is no need for new equipment.
A SIP trunk provides voice connectivity to the telephone network by only using an internet connection. Based on the Session Initiation Protocol, SIP trunks handle a high volume of inbound or outbound calls using a Private Branch Exchange (PBX) server.
SIP is short for Session Initiation Protocol. SIP essentially dictates how a communications session is established and how it is terminated, initiating the connection between IP addresses. SIP technology can also send audio, images, video, and documents to support everyday voice calls. That also means, SIP users no longer have to maintain two separate networks for data and phone calls. While numerous protocols may be used in a VoIP system, SIP is the most common.