Patent ID: 8706752

Claim:
A method of determining a list of members for a Group Push to Talk Session in a communications network that uses a Session Initiation Protocol, the method comprising: at a Search Proxy function, receiving from a requesting network node a search request message, the search request message comprising at least four instructions, the instructions comprising: an instruction to limit a maximum time for a search operation; an instruction to send search results in segmented blocks; an instruction to return the search results according to a predetermined format, such that found members are ordered in the search results according to any one of alphabetical order, predetermined prioritized users or groups of users, and an exclusion predetermined users or groups of users; and an instruction to perform the search according to a predetermined pattern; performing a search for members with which to populate the list according to the at least four instructions included in the search request message; and sending the search results, from each domain that is searched, in segmented blocks to a receiving node before the maximum time at the search proxy function expires.