Patent ID: 7990892
Filing Date: 2011-08-02
Classification: H04L

Abstract:
1. A method of selecting an Internet Protocol (IP) telephony route for routing a call to an IP telephony destination, the method being performed within a first location server belonging to a first IP telephony domain deployed on at least one autonomous system, the first location server managing locations of clients of the first IP telephony domain and able to interface with at least one neighboring location server to discover locations of clients managed by other IP telephony domains, each IP telephony domain having an identifier, the method comprising the following steps: receiving at least one route update message from a second location server, said route update message defining at least one updated IP telephony route comprising a list of identifiers of autonomous systems through which said route update message has passed from said IP telephony destination and a list of IP telephony domains through which said route update message has passed from said IP telephony destination; extracting from said list of IP telephony domains, the identifier of an IP telephony domain with which said IP telephony destination is associated, referred to as a destination identifier; obtaining a set of at least one IP telephony route serving said IP telephony destination, as previously stored within said first location server; searching for at least one IP telephony route for which said IP telephony destination is identical to said destination identifier, referred to as searched-for IP routes; selecting the IP telephony route within said set of IP telephony routes, for which a list of autonomous systems through which that IP telephony route passes includes the same autonomous system identifiers as said list of autonomous system identifiers of said searched-for IP routes, when such an IP telephony route within the set exists; selecting the IP telephony route from said set of IP telephony routes when there exists no IP telephony route in the set for which a list of autonomous systems through which that IP telephony route passes includes the same autonomous system identifiers as said list of autonomous system identifiers of said searched-for IP routes, by applying at least one predetermined criterion; and storing said selected IP telephony route.