SIP trunking is a technology that allows voice over Internet Protocol (VoIP) and other digital communication services to be delivered over an internet connection. It is based on the Session Initiation Protocol (SIP), which is an application layer protocol that enables the setup, management, and teardown of VoIP calls. SIP trunking is used to consolidate multiple branches or channels of individual SIP sessions, which are then trunked together through an IP-enabled Private Branch Exchange (PBX) . The resulting virtual phone lines, known as SIP trunks, connect a companys phone connections to its Internet Telephony Service Provider (ITSP) .
SIP trunks can carry not only voice calls but also multimedia communication that combines voice, video, and messaging services. They are replacing traditional analogue and ISDN phone lines, with many countries now scheduling the termination of ISDN services. SIP trunking is flexible, reliable, and lightweight, which means that businesses can focus on their operations instead of the technicalities.
Benefits of SIP trunking include greater purchasing power, scalability, and cost savings. It also allows for remote employees and employees that travel or relocate often to stay connected.