Packet routing method, proxy server and apparatus

摘要

A method is described of routing a packet comprising routing information between a mobile host and a correspondent host in respective first and further network domains, at least the first network domain comprising a plurality of subnets, said mobile host being attached to one of said subnets. The method comprises registering the mobile host with the first network domain, said registration including assigning a global IP address and a local IP address to said mobile host, said local IP address being associated with the subnet to which the mobile host is attached; communicating said local IP address to said mobile host; using the global IP address as the routing information between the domains; reformatting said packet by replacing the global IP address with the local IP address upon receipt of the packet in the first network domain; and communicating the reformatted request to the mobile host via the associated subnet. A proxy server and apparatus for use in this method are also disclosed.

主权项

1. A method of routing a session initiation protocol (SIP) packet, wherein the SIP packet comprises routing information between a mobile host and a correspondent host in respective first and further network domains, at least the first network domain comprising a plurality of subnets, said mobile host being attached to one of said subnets, the method comprising:
using a mapping between a SIP-Uniform Resource Identifier (URI), a local IP address and a global IP address to identify the mobile host inside the first network domain; receiving a new local IP address of the mobile host upon the mobile host attaching to another one of said subnets, wherein the global IP address has validity outside the first network domain and wherein the new local IP address has validity inside the another one of said subnets, said routing information comprising the global IP address; refreshing the mapping by replacing the local IP address with the new local IP address in the mapping; reformatting said SIP packet by replacing the global IP address in a single IP header of the SIP packet with the new local IP address in the single IP header of the SIP packet upon receipt of the SIP packet in the first network domain; and communicating the reformatted SIP packet to the mobile host via the subnet to which the mobile host is attached.