Patent ID: 7573873
Filing Date: 2009-08-11
Classification: H04L,H04M

Abstract:
1. In a communication system comprising a first edge network, a second edge network, a first gatekeeper, a second gatekeeper, and an intermediate network, each of said networks carrying digital data comprising data packets, each of said data packets having a source address and a destination address, a method for communicating over said intermediate network between a caller station and a callee station, said caller station producing a first caller signal, said caller station being connected to said first edge network, said callee station being accessible via said intermediate network, said caller station being identified on said first edge network by a private caller address and identified on said intermediate network by a proxy public caller address, said callee station being identified on said first edge network by a proxy private callee address and identified on said intermediate network by a proxy public callee address, said caller station being associated with a caller station number, said callee station being associated with a callee station number, said intermediate network being connected to a first router and to a second router, said first router being identified on said intermediate network by a first public router address, said second router being identified on said intermediate network by a second public router address, said method comprising the steps of: registering said caller station with a server connected to said intermediate network, wherein said intermediate network is connected to said first gatekeeper and to said second gatekeeper, wherein said first gatekeeper is identified by a first public gatekeeper address and controls when said first router allocates proxy public addresses and proxy private addresses from a pool of addresses available to said first router, wherein said second gatekeeper is identified on said intermediate network by a second public gatekeeper address and controls when said second router allocates proxy public addresses and proxy private addresses from a pool of addresses available to said second router, wherein registering said caller station includes (i) transmitting said caller station number, said private caller address, said first public router address, and said first public gatekeeper address to said server, and (ii) said server storing said caller station number, said private caller address, said first public router address, and said first public gatekeeper address transmitted to said server; registering said callee station with said server connected to said intermediate network, wherein registering said callee station includes (i) transmitting said callee station number, said private callee address, said second public router address, and said second public gatekeeper address to said server, and (ii) said server storing said callee station number, said private callee address, said second public router address, and said second public gatekeeper address transmitted to said server; after registering said caller station and said callee station with said server, setting up a call from said caller station to said callee station, wherein setting up said call includes (i) said first gatekeeper transmitting to said server a first lookup message including said callee station number and said server responsively sending said second public gatekeeper address to said first gatekeeper, (ii) said first gatekeeper transmitting to said second gatekeeper a setup message including said callee station number, and (iii) said second gatekeeper transmitting to said server a second lookup message including said callee station number included in said setup message, and said server responsively sending said second gatekeeper said private callee address, and during said call; A) said first router receiving said first caller signal from said caller station over said first edge network, said first caller signal comprising first caller data packets, said first caller data packets having said private caller address as their source addresses and said proxy private callee address as their destination addresses; B) for each of said first caller data packets, said first router translating said private caller address into said proxy public caller address and said proxy private callee address into said proxy public callee address, whereby said first router generates second caller data packets; C) said first router transmitting over said intermediate network to said second router a second caller signal comprising said second caller data packets; D) said second router receiving said second caller signal from said intermediate network, E) for each of said second caller data packets, said second router translating said proxy public callee address into said proxy private callee address and said proxy public caller address into said private caller address, whereby said second router generates third caller data packets; and F) said second router transmitting over said second edge network to said callee station a third caller signal comprising said third caller data packets.