Method of switching fabric for counteracting a saturation tree occurring in a network with nodes

Abstract

Method and Switching fabric for ccounteracting a saturation tree occurring in a network with nodes An example of a method comprises the steps of generating at a local node where a congestion emerges a first congestion information; sending the first congestion information to at least one upstream node; responsive to one received first congestion information comparing the content of the received first congestion information with a present local status based on a set of predefined rules in order to identify at least one packet stream causing the congestion, and generating a second congestion information comprising the identified at least one packet stream causing the congestion; and sending the second congestion information to at least one further upstream node from where the identified at least one packet stream was received.

1 . A method for counteracting a saturation tree occurring in a network having nodes, comprising: 
 generating at a local node where a congestion emerges a first congestion information;    sending the first congestion information to at least one upstream node;    responsive to one received first congestion information 
 comparing the content of the received first congestion information with a present local status based on a set of rules in order to identify at least one packet stream causing the congestion, and  
 generating a second congestion information comprising the identified at least one packet stream causing the congestion; and  
   sending the second congestion information to at least one further upstream node.    
   
   
       2 . A method according to  claim 1 , wherein the step of sending the second congestion information comprises 
 forwarding the second congestion information to a source node from which the identified at least one packet stream originates.    
   
   
       3 . A method according to  claim 1 , wherein the step of generating a first congestion information at a local node further comprises detecting the emerging congestion by applying the set of rules.  
   
   
       4 . A method according to  claim 1 , wherein the first congestion information comprising an identifier identifying a congested root is sent upstream, the at least one upstream node receiving the first congestion information stores in dependence on the set of rules the identifier in one of a first list indicating the packet stream causing the congestion and a second list indicating packet streams suspected of causing congestion.  
   
   
       5 . A method according to  claim 4 , wherein the second congestion information comprising the identifier is sent further upstream, the at least one further upstream node receiving the second congestion information store in dependence on the set of rules the identifier in one of the first list and the second list.  
   
   
       6 . A method according to  claim 4 , wherein the identifier identifies multiple data flows.  
   
   
       7 . A method according to  claim 4  further comprising comparing based on the set of rules each identifier of incoming packet streams with the identifiers stored in the second list, if a condition of the set of rules with respect to one identifier holds, the one identifier is transferred from the second list to the blacklist.  
   
   
       8 . A method according to  claim 4 , wherein the second congestion information with the identifier is sent upstream if the identifier is stored more than once in the first list.  
   
   
       9 . A method according to  claim 4 , wherein a receiving source node at least reduces the sending of the packet stream identified by the identifier and sends a test packet to the local node where the congestion emerged, wherein entries of the received identifier in the second lists are removed along the way of the test packet to the local node where the congestion emerged.  
   
   
       10 . A switching fabric for counteracting a saturation tree occurring in a network having nodes, comprising 
 a local processing unit and a local memory adapted to generate at a local node where a congestion emerges a first congestion information;    a local port controlled by the local processing unit for sending the first congestion information to at least one upstream node;    a further processing unit and a further memory adapted to compare the content of the received first congestion information with a present local status based on a set of rules in order to identify at least one packet stream causing the congestion, and to generate a second congestion information comprising the identified at least one packet stream causing the congestion; and    a further port for sending the second congestion information to at least one further upstream node.    
   
   
       11 . A method according to  claim 1 , wherein the second congestion information comprises an expedite information.  
   
   
       12 . The switching fabric according to  claim 10  further comprising 
 a first list for storing an identifier indicating a data stream causing the congestion, and    a second list for storing the identifier indicating data streams suspected of causing congestion.    
   
   
       13 . An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing counteraction of a saturation tree occurring in a network having nodes, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect the steps of: 
 generating at a local node where a congestion emerges a first congestion information;    sending the first congestion information to at least one upstream node;    responsive to one received first congestion information 
 comparing the content of the received first congestion information with a present local status based on a set of rules in order to identify at least one packet stream causing the congestion, and  
 generating a second congestion information comprising the identified at least one packet stream causing the congestion; and  
   sending the second congestion information to at least one further upstream node.    
   
   
       14 . A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for counteracting a saturation tree occurring in a network having nodes, said method steps comprising the steps of  claim 1 .  
   
   
       15 . A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for counteracting a saturation tree occurring in a network having nodes, said method steps comprising the steps of  claim 2 .  
   
   
       16 . A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for counteracting a saturation tree occurring in a network having nodes, said method steps comprising the steps of  claim 3 .  
   
   
       17 . A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for counteracting a saturation tree occurring in a network having nodes, said method steps comprising the steps of  claim 4 .  
   
   
       18 . A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for counteracting a saturation tree occurring in a network having nodes, said method steps comprising the steps of  claim 5 .  
   
   
       19 . A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing functions of a switching fabric for counteracting a saturation tree occurring in a network having nodes, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect the functions of  claim 10 .  
   
   
       20 . A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing functions of a switching fabric for counteracting a saturation tree occurring in a network having nodes, the computer readable program code means in said computer program product comprising computer readable program gram code means for causing a computer to effect the functions of  claim 12.