A SIP trunk
is a service offered by an ITSP
(Internet Telephony Service Provider) that permits businesses that have a PBX installed to use
Voice-over-IP (VoIP) also outside the enterprise network by using the same connection as the Internet
SIP Trunking is simply a single conduit pipeline for multimedia elements (voice, video and data).
SIP Trunking reduces or eliminates the need for PSTN media gateways as well as reduce or eliminate
the need for narrow-band voice circuits. SIP Trunking provides a smart and cost effective solution to
customers by eliminating the need to purchase additional equipment, such as managed media gateway
devices to interface between IP voice to the PSTN.
A business should look into purchasing SIP Trunks when they decide that their need are best met with a
premise based system. This system is often referred to as an IP-PBX. Coupled with SIP Trunks, an IP-PBX
serves up similar features to hosted solutions. Sip Trunks typically save a business customer money over
a hosted solutions in that SIP Trunk can serve the needs of three to four employees while a hosted seat
is used for each employee.