Understanding SIP
SIP means Session initiation Protocol. It allows the creation of sessions which let information, voice, video, or other software systems operate over IP-based networks like the internet.
In a PSTN telephone network the user has a wired connection (circuit) from their phone directly to the phone of the person that they wish to talk to. SIP can reach any user connected to the internet or to a private IP (internet protocol) network through a concept called SIP trunks.
SIP permits the use of a wide range of devices, which can retain their identity (think phone number) wherever they are connected to the SIP system.
