Patent ID: 7796990

Claim:
A method, comprising: receiving a signaling message at a first network node from a proxy network node, said signaling message providing a first private user identity and a first public user identity; computing a first key from said first private user identity; matching said first key to at least one key range, each said at least one key range being associated with a network node; determining a second network node by detecting that said first key belongs to the key range of said second network node; providing said signaling message to said second network node; obtaining data associated with said first private user identity in said second network node; extracting said first public user identity from said signaling message in said second network node; computing a second key from said first public user identity; routing said signaling message to a third network node identified with said second key; obtaining data associated with said first public user identity in said third network node; registering a registration status of said first public user identity as active in said third network node; registering an identity of said proxy network node in said data associated with said first public user identity; receiving a session establishment message at a fourth network node, said session establishment message comprising said first public user identity; determining a third key from said first public user identity in said fourth network node; routing said session establishment message to said third network node identified with said third key; receiving said session establishment message at said third network node; determining said registration status of said first public user identity; and in response to said determination, transmitting said session establishment message to said proxy network node.