Based on Session Initiation Protocol (SIP), SIP Trunking is an application layer protocol used to set-up real-time communications over the Internet. A SIP Trunk establishes dependable telecom service from your on-site Public Branch eXchange (PBX) to anyone, whether they are in the same office, in an out-of-state office, or on a cell phone on the far side of the world. By establishing one SIP Trunk to a centralized IP PBX, Genuity Technology Group can route calls throughout your network efficiently and reliably.