Session Initiation Protocol (SIP) is a communications protocol that is used to send voice and media services through the internet to an IP PBX. PBXs (Private Branch Exchange) connect telephone extensions to the Public Switched Telephone Network (PSTN) and internal phone extensions. Traditional PBXs delivers voice calls through the PSTN.
SIP Trunking delivers all forms of media including voice, data and video over a data network. Instead of having a physical wire, a SIP Trunks is a virtual phone like that’s provided by a SIP trunk provider which removes the necessity of a traditional phone service connection and eliminates the need for analogue phone lines. As a result, SIP is usually preferred by companies with multiple office locations or remote workers, whose employees rely on multimedia communications.