Simply put: An SIP (Session Initiation Protocol) trunk is a service that allows businesses with an installed PBX to use real-time communications including VoIP. By connecting an SIP trunk to an internal traditional PSTN (public switched telephone network) phone system, companies can communicate over IP outside the enterprise. What’s more, companies can replace traditional fixed PSTN lines with an IP phone system connected externally through an SIP-trunking service, thereby creating a single conduit for multimedia components including voice, video and data. As a result, an SIP-trunking service typically delivers greater cost savings and increased reliability.
– Voip News: The essential guide to SIP Trunking
Find out what SIP Trunk offerings we have at our Cloud Telephony Services page