Obtaining and Using Temporarily Routable User Agent (UA) URIs (TRUU) in the Session Initiation Protocol (SIP)
Lucent Technologies
Several applications of the Session Initiation Protocol (SIP) require a user agent (UA) to construct a URI which can only be used to route messages to that specific UA instance for a time limited period, for example only for the duration of a particular call. A URI whose lifetime is controlled by the UA instance to which it indirectly routes is called a Temporarily Routable UA URI (TRUU). This document describes an extension to SIP for obtaining a TRUU from a registrar, and for using this TRUU as a Contact.