Forking proxy

A forking proxy, in the context of a communications system using Session Initiation Protocol (SIP), is a server that attempts to find a correspondent by searching several locations.

SIP proxy servers that route messages to more than one destination are called forking proxies.

The forking of SIP requests means that multiple dialogs can be established from a single request. 
This also explains the need for the two-sided dialog identifier; without a contribution from the recipients, 
the originator could not disambiguate the multiple dialogs established from a single request.

SIP forking refers to the process of "forking" a single SIP call to multiple SIP endpoints. This is a very powerful feature of SIP. A single call can ring many endpoints at the same time.

With SIP forking you can have your desk phone ring at the same time as your softphone or a SIP phone on your mobile. For example, you would use SIP forking to ring your deskphone and your Android SIP Phone at the same time, allowing you to take the call from either device easily. No forwarding rules would be necessary as both devices would ring. In the same manner SIP forking can be used in an office and allow the secretary to answer calls to the extension of his/her boss when he is away or unable to take the call.