session process and system

Abstract

A process for establishing a session between a first node and a second node of a communications network, the process including receiving a first request addressed from the first node and addressed to the second node; sending, in response to receipt of the first request, a response addressed to the first node to cause the first node to send a second request addressed to the second node, the response including first validation data; receiving the second request sent by the first node, the second request including second validation data; and determining, on the basis of the second validation data, whether to establish the session.

1 . A process for establishing a session between a first node and a second node of a communications network, the process including:
 receiving a first request to initiate a session between said first node and said second node, said first request being addressed from said first node and addressed to said second node and being encapsulated with a connectionless transport layer protocol;   sending, in response to receipt of said first request, a response addressed to said first node to cause said first node to send a second request to initiate a session between said first node and said second node, said second request being addressed to said second node, said response including first validation data;   receiving said second request sent by said first node, said second request including second validation data; and   determining, on the basis of said second validation data, whether to establish said session.   
     
     
         2 . A process for establishing a SIP session between a first node and a second node of a communications network, the process including:
 receiving a first SIP  INVITE  request addressed from said first node and addressed to said second node;   sending, in response to receipt of said first SIP  INVITE  request, a SIP REDIRECT response addressed to said first node to cause said first node to send a second SIP INVITE request addressed to said second node, said SIP REDIRECT response including first validation data;   receiving said second SIP  INVITE  request sent by said first node, said second SIP  INVITE  request including second validation data; and   determining, on the basis of said second validation data, whether to establish said session.   
     
     
         3 . The process of  claim 1 , wherein said determining includes determining whether to establish said session on the basis of a comparison of said first validation data and said second validation data. 
     
     
         4 . The process of  claim 1 , including processing said first request to generate said first validation data. 
     
     
         5 . The process of  claim 4 , wherein said first validation data is generated from at least one of an address of said first node and an address of said second node. 
     
     
         6 . The process of  claim 4 , wherein said validation data is based on a time of receipt of said first request. 
     
     
         7 . The process of  claim 4 , wherein said processing includes applying a hash function to one or more header fields of said first request. 
     
     
         8 . The process of  claim 4 , wherein said processing includes applying a hash function to a timestamp. 
     
     
         9 . The process of any one of  claim 1 , wherein said first validation data includes a cryptographic signature. 
     
     
         10 . The process of any one of  claim 1 , wherein said first request includes a TO header field including an address of said first node, and said response includes a header field including said address of said first node and said first validation data. 
     
     
         11 . The process of any one of  claim 1 , wherein said step of determining includes generating third validation data from one or more header fields of said second request, and determining whether to establish said session on the basis of a comparison of said third validation data with validation data generated from one or more corresponding header fields of said first request. 
     
     
         12 . The process of  claim 11 , wherein said step of determining includes establishing said session only if the first validation data generated for the first request is the same as the third validation data generated from the second request. 
     
     
         13 . The process of  claim 1 , wherein said step of determining includes forwarding said second request to said second node only if the validation data generated for the first request is the same as the validation data generated from the second request. 
     
     
         14 . The process of  claim 1 , wherein said first request is encapsulated using a connectionless transport layer protocol. 
     
     
         15 . The process of  claim 14 , wherein said first request is encapsulated in a UDP packet. 
     
     
         16 . The process of  claim 1 , wherein the process is executed by a third node of said communications network. 
     
     
         17 . The process of  claim 16 , wherein said communications network is configured so that all packets sent to said second node are received by said third node for forwarding to said second node. 
     
     
         18 . A system or device having one or more components for executing the steps of  claim 1 . 
     
     
         19 . A proxy server having one or more components for executing the steps of  claim 1 . 
     
     
         20 . A VoIP telephone having one or more components for executing the steps of  claim 1 . 
     
     
         21 . A computer-readable storage medium having stored thereon program code for executing the steps of  claim 1 . 
     
     
         22 . A node of a communications network, the node being adapted to:
 receive a first request addressed from said first node and addressed to said second node, said first request being encapsulated with a connectionless transport layer protocol;   send a response addressed to said first node to cause said first node to send a second request addressed to said second node, said response including first validation data;   receive said second request sent by said first node, said second request including second validation data; and   determine, on the basis of said second validation data, whether to establish said session.   
     
     
         23 . The node of  claim 22 , wherein said requests are SIP INVITE messages and said response is a SIP REDIRECT message. 
     
     
         24 . The node of  claim 22 , wherein said node is adapted to generate said first validation data from said first request. 
     
     
         25 . The node of  claim 22 , wherein said node is adapted to determine whether to establish said session on the basis of a comparison of said first validation data and said second validation data.