A system and method for efficient and accurate establishment of SIP sessions between calling and called end-points. A calling endpoint creates a SIP INVITE request including a header portion and a body portion. The header portion includes standard routing information and the body portion includes additional information about the user and relevant to caller's intent. A SIP server receives a SIP INVITE request and determines an address of the called end-point as a function of the standard routing information contained in the header and the additional caller information contained in the body. The SIP server routes the session to the determined address.