SIP dilivery methods and ROI

This document discusses SIP trunking, which uses the Session Initiation Protocol (SIP) to connect an IP PBX or hybrid phone system to the existing telephone network infrastructure (PSTN) via a managed data service or internet connection. It outlines various VoIP protocols, bandwidth requirements, delivery methods (managed vs unmanaged internet), considerations around quality of service, and examples of pricing models and ROI comparisons between SIP trunking and traditional phone lines.