Method and apparatus for reducing load distribution delay in an internet protocol switch

Abstract

Method and apparatus for reducing load distribution delay in an internet protocol switch. A system of messaging allows leader and follower cards within a switch to communicate without spanning the external network and without significant involvement by the central computing module within a switch. When a call setup request is received by a leader card, it sends a broadcast message to follower cards within a multicast group. Each follower card responds with address and channel information which enable the leader card to perform load balancing and establish a connection through the appropriate follower card.

We claim:  
     
         1 . A method in a switch of establishing a network connection with an initiating endpoint, the method comprising the steps of: 
 receiving at a leader card, a setup message from the initiating endpoint;    broadcasting a broadcast message to one or more adapter cards in a multicast group;    receiving at the leader card, one or more response messages to the broadcast message, each response message including address information for one follower card; and    negotiating the network connection through a follower card so that an even connection distribution is established among available follower cards.    
     
     
         2 . The method of  claim 1  wherein the broadcast and response messages are in user datagram protocol (UDP) format.  
     
     
         3 . The method of  claim 2  wherein the broadcast and response messages include a message type field, a callid field, and an internet protocol (IP) address and port number field.  
     
     
         4 . The method of  claim 3  wherein the response message also includes a channel identification information field.  
     
     
         5 . Apparatus for establishing a network connection with an initiating endpoint, the apparatus comprising: 
 means for receiving a setup message from the initiating endpoint;    means for broadcasting a broadcast message to one or more adapter cards in a multicast group;    means for receiving at a leader card, one or more response messages to the broadcast message, each response including address information for one follower card; and    means for negotiating the network connection through a follower card so that an even connection distribution is established among available follower cards.    
     
     
         6 . The apparatus of  claim 5  wherein the broadcast and response messages are in user datagram protocol (UDP) format.  
     
     
         7 . The apparatus of  claim 6  wherein the broadcast and response messages include a message type field, a callid field, and an internet protocol (IP) address and port number field.  
     
     
         8 . The apparatus of  claim 7  wherein the response message also includes a channel identification information field.  
     
     
         9 . A switch for establishing a network connection with an initiating endpoint, the switch including a leader card and at least one follower card, the switch further including a computer program comprising: 
 computer program code for receiving, at the leader card, a setup message from the initiating endpoint;    computer program code for broadcasting a broadcast message for one or more adapter cards in a multicast group;    computer program code for receiving at a leader card, one or more response messages to the broadcast message, each response including address information for one follower card; and    computer program code for negotiating the network connection through a follower card so that an even connection distribution is established among available follower cards.    
     
     
         10 . The switch of  claim 9  wherein the broadcast and response messages are in user datagram protocol (UDP) format.  
     
     
         11 . The switch of  claim 10  wherein the broadcast and response messages include a message type field, a callid field, and an internet protocol (IP) address and port number field.  
     
     
         12 . The switch of  claim 11  wherein the response message also includes a channel identification information field.  
     
     
         13 . An adapter card for a switch, the adapter card operable to create broadcast messages and response messages to enable even load distribution among follower cards within the switch, the broadcast messages and response messages comprising: 
 a message type field;    a callid field appended onto the message type field; and    an address and port number field appended onto the callid field.    
     
     
         14 . The adapter card of  claim 13  wherein the response messages further comprise a channel identifier number field appended to the address and port number field.  
     
     
         15 . The adapter card of  claim 14  wherein the broadcast and response messages are in user datagram protocol (UDP) format.  
     
     
         16 . A switch containing a plurality of adapter cards, each adapter card operable to create broadcast messages and response messages to enable even load distribution among follower cards within the switch, the broadcast messages and response messages comprising: 
 a message type field;    a callid field appended onto the message type field; and    an address and port number field appended onto the callid field.    
     
     
         17 . The switch of  claim 16  wherein the response messages further comprise a channel identifier number field appended to the address and port number field.  
     
     
         18 . The switch of  claim 17  wherein the broadcast and response messages are in user datagram protocol (UDP) format.