Distributed network address translation control

Abstract

A distributed network address translation (NAT) system is used to transport data packets between private and public network domains. A packet modifier substitutes public and private network address information in packets that are crossing between public and private domains to and from the end system. A network application server has an address mapping table and communicates with the packet modifier over a control protocol. The network application server generates address mappings which the packet modifier uses for modification of data packets passing through it.

1 . A method of operating a packet modifier associated with a first communications network, the method comprising:
 receiving a first address mapping from a first network application server, the first address mapping being associated with a request by an end system associated with the first communications network to establish a voice stream with a remote system associated with a second communications network, the first address mapping being based on a first pool of addresses maintained by the first network application server;   receiving a second address mapping from a second network application server, the second address mapping being associated with a request by the end system to establish a data stream with the remote system, the second address mapping being based on a second pool of addresses maintained by the second network application server, the second pool of addresses being different from the first pool of addresses;   mapping the voice stream from the end system destined for the remote system in accordance with the first address mapping, the voice stream not passing through the first network application server and not passing through the second network application server; and   mapping the data stream from the end system destined for the remote system in accordance with the second address mapping, the data stream not passing through the first network application server and not passing through the second network application server.   
     
     
         2 . The method of  claim 1 , comprising sending the request to establish the voice stream from the packet modifier to the first network application server. 
     
     
         3 . The method of  claim 2 , comprising receiving the request to establish the voice stream from the remote system. 
     
     
         4 . The method of  claim 3 , wherein sending the request to establish the voice stream from the packet modifier to the first network application server comprises forwarding the request to establish the voice stream which was received from the remote system to the first network application server. 
     
     
         5 . The method of  claim 1 , comprising sending the request to establish the data stream from the packet modifier to the second network application server. 
     
     
         6 . The method of  claim 5 , comprising receiving the request to establish the data stream from the remote system. 
     
     
         7 . The method of  claim 6 , wherein sending the request to establish the data stream from the packet modifier to the second network application server comprises forwarding the request to establish the data stream which was received from the remote system to the second network application server. 
     
     
         8 . The method of  claim 1 , comprising modifying voice packets sent from the end system to the remote system according to the first address mapping. 
     
     
         9 . The method of  claim 1 , comprising modifying data packets sent from the end system to the remote system according to the second address mapping. 
     
     
         10 . The method of  claim 1 , comprising modifying data packets sent from the remote system to the end system according to the second address mapping. 
     
     
         11 . The method of  claim 1 , wherein receiving the first address mapping from the first network application server comprises receiving the first address mapping using a control protocol. 
     
     
         12 . The method of  claim 1 , wherein receiving the second address mapping from the second network application server comprises receiving the second address mapping using a control protocol. 
     
     
         13 . The method of  claim 1 , wherein the first address mapping comprises a Network Address Translation (NAT). 
     
     
         14 - 15 . (canceled) 
     
     
         16 . The method of  claim 1 , comprising sending a confirmation of the second address mapping from the packet modifier to the second network application server. 
     
     
         17 . The method of  claim 1 , wherein the second address mapping comprises a Network Address Translation (NAT). 
     
     
         18 . The method of  claim 1 , wherein the first address mapping comprises a Network Address Port Translation (NAPT). 
     
     
         19 . The method of  claim 1 , wherein the second address mapping comprises a Network Address Port Translation (NAPT). 
     
     
         20 . The method of  claim 1 , comprising sending a confirmation of the first address mapping from the packet modifier to the first network application server.