Cisco Systems This document presents the framework and requirements for usage of the Session Initiation Protocol (SIP) to convey user location information from one Session Initiation Protocol (SIP) entity to another SIP entity. We consider cases where location information is conveyed from end to end, as well as cases where message routing by intermediaries is influenced by the location of the session initiator. We offer a set of solutions to the requirements, based on the scenario(s) being addressed.