SIP Trunking gives you the best of both worlds: the improved functionality and cost-efficiency of VoIP phone plans and the ability to keep your current phone system.
Technically speaking, SIP stands for "Session Initiation Protocol." Trunking refers the blend of data and voice connections into a single line. Instead of using both a phone network and a data network, you can use the Internet to transfer your voice and your data. SIP trunking uses your onsite PBX (that's the telephone switching system that you already have) to route the calls. But the difference in price comes from the consolidation of your connections and the increased efficiency that brings.
Providers like can customize their plans to provide top-notch SIP service. Check out these providers and others below, on our SIP Trunking comparison table. We noted some of the nicer features below.
Increased reliability, backed by the SIP Trunk Providers
DID calling for every extension
Local and long distance calling