Joint IP/optical layer restoration after a router failure

Abstract

A method and system for providing joint IP/Optical Layer restoration mechanisms for the IP over Optical Layer architecture, particularly for protecting against router failure within such architecture, includes any one of plural node elements participating in the detection and restoration of the joint IP/Optical Layer architecture upon the failure of a router in one of the nodes. The plural node elements may include, but are not limited to, one of plural routers and an optical cross-connect.

We claim:  
     
         1 . A node method of restoring an IP/Optical Layer after failure of a router in one of a plurality of nodes, said method comprising the steps of: 
 detecting a failure in a path to a first node;    transmitting a request to an optical network to re-establish the path; and    reestablishing the failed path using a redundant router in place of a failed router.    
     
     
         2 . The method of  claim 1 , wherein the path is a light path between the first node and a second node.  
     
     
         3 . The method of  claim 2 , wherein the failure in the path to the other of the plurality of nodes is detected by a router at a second node, and wherein the failed router and the redundant router are at the first node.  
     
     
         4 . The method of  claim 2 , wherein the failure in the path to the other of the plurality of nodes is detected by the redundant router at the first node, and wherein the failed router is at the first node.  
     
     
         5 . The method of  claim 2 , wherein the failure in the path to the first node is detected by an optical cross-connect at the first node, and wherein the failed router and the redundant router are at the first node.  
     
     
         6 . The method of  claim 3 , wherein said transmitting step includes the router at the second node transmitting the request to an optical cross-connect at the second node to reestablish the path to the first node by using the redundant router in place of the failed router.  
     
     
         7 . The method of  claim 6 , wherein said transmitting step further includes the optical cross-connect at the second node transmitting the request to an optical cross-connect at the first node.  
     
     
         8 . The method of  claim 4 , wherein said transmitting step includes the redundant router transmitting the request to an optical cross-connect at the first node to re-establish the path by using the redundant router in place of the failed router.  
     
     
         9 . The method of  claim 5 , wherein said transmitting step includes the optical cross-connect at the first node transmitting the request to an optical cross-connect at another node to re-establish the path by using the redundant router in place of the failed router at the first node.  
     
     
         10 . A method of restoring an IP/Optical Layer after failure of one of plural routers at a first node that further includes an optical cross-connect, said method comprising the steps of: 
 a router at a second node detecting a failure in a path between the router at the second node and a router at the first node;    transmitting a request to an optical network to re-establish the path; and    reestablishing the path using a redundant router in place of the failed router at the first node.    
     
     
         11 . The method of  claim 10 , wherein the path is a light path between the first node and the second node.  
     
     
         12 . The method of  claim 11 , wherein said transmitting step includes the router at the second node transmitting the request to an optical cross-connect at the second node to reestablish the path.  
     
     
         13 . The method of  claim 12 , wherein said transmitting step further includes the optical cross-connect at the second node transmitting the request to the optical cross-connect at the first node.  
     
     
         14 . A method of restoring an IP/Optical Layer after failure of one of plural routers in a first node that further includes an optical cross-connect, said method comprising the steps of: 
 a first router at the first node detecting a failure in a path between a second router at the first node and a router at a second node;    transmitting a request to an optical network to re-establish the path; and    reestablishing the path using the first router in place of the second router.    
     
     
         15 . The method of  claim 14 , wherein the path is a light path.  
     
     
         16 . The method of  claim 15 , wherein said transmitting step includes the first router transmitting the request to an optical cross-connect at the first node to re-establish the path by using the first router in place of the second router.  
     
     
         17 . A method of restoring an IP/Optical Layer after failure of one of plural routers in a first node, said method comprising the steps of: 
 an optical cross-connect at the first node detecting a failure in a path between a first router at the first node and a router at a second node; and    reestablishing the path using a second router in place of the first router at the first node.    
     
     
         18 . A computer-readable medium at a node method of an IP/Optical Layer, said computer-readable medium having computer-executable instructions for performing, after failure of a router in one of a plurality of nodes, the steps of: 
 detecting a failure in a path to a first node;    transmitting a request to an optical network to re-establish the path; and    reestablishing the failed path using a redundant router in place of a failed router.    
     
     
         19 . The computer-readable medium having computer-executable instructions according to  claim 18 , wherein the path is a light path between the first node and a second node.  
     
     
         20 . The computer-readable medium having computer-executable instructions according to  claim 19 , wherein the failure in the path to the other of the plurality of nodes is detected at a router at a second node, and wherein the failed router and the redundant router are at the first node.  
     
     
         21 . The computer-readable medium having computer-executable instructions according to  claim 19 , wherein the failure in the path to the other of the plurality of nodes is detected at the redundant router at the first node, and wherein the failed router is at the first node.  
     
     
         22 . The computer-readable medium having computer-executable instructions according to  claim 19 , wherein the failure in the path to the first node is detected by an optical cross-connect at the first node, and wherein the failed router and the redundant router are at the first node.  
     
     
         23 . The computer-readable medium having computer-executable instructions according to  claim 20 , wherein said transmitting step includes the router at the second node transmitting the request to an optical cross-connect at the second node to re-establish the path to the first node by using the redundant router in place of the failed router.  
     
     
         24 . The computer-readable medium having computer-executable instructions according to  claim 23 , wherein said transmitting step further includes the optical cross-connect at the second node transmitting the request to an optical cross-connect at the first node.  
     
     
         25 . The computer-readable medium having computer-executable instructions according to  claim 21 , wherein said transmitting step includes the redundant router transmitting the request to an optical cross-connect at the first node to re-establish the path by using the redundant router in place of the failed router.  
     
     
         26 . The computer-readable medium having computer-executable instructions according to  claim 22 , wherein said transmitting step includes the optical cross-connect at the first node transmitting the request to an optical cross-connect at another node to reestablish the path by using the redundant router in place of the failed router at the first node.  
     
     
         27 . An IP/Optical Layer system, comprising: 
 a first router at a first node;    a second router at a second node that receives a light path transmitted from said first router;    an optical network that receives a request to re-establish the light path transmitted from said first router, when said first router determines that the light path has failed, and reestablishes the light path using a third router in place of said second router at the second node.    
     
     
         28 . An IP/Optical Layer system according to  claim 27 , wherein the first router determines that the light path has failed when the second router fails.  
     
     
         29 . An IP/Optical Layer system according to  claim 28 , wherein said optical network includes an optical cross-connect at the first node, and said optical-cross connect at the first node transmits the request to re-establish the light path to a cross-connect at the second node.  
     
     
         30 . An IP/Optical Layer system, comprising: 
 a first router at a first node;    a second router at the first node;    a third router at a second node that receives a light path transmitted from said second router;    an optical network that receives a request to re-establish the light path transmitted from said first router, when said first router determines that the light path between said second router and said third router has failed, and re-establishes the light path using said first router in place of said second router at the first node.    
     
     
         31 . An IP/Optical Layer system according to  claim 30 , wherein the first router determines that the light path has failed when the second router fails.  
     
     
         32 . An IP/Optical Layer system according to  claim 31 , wherein said optical network includes an optical cross-connect at the first node, and said optical-cross connect at the first node transmits the request to re-establish the light path to a cross-connect at the second node.  
     
     
         33 . An IP/Optical Layer system, comprising: 
 a first node having plural routers;    a second node having plural routers; and    an optical cross-connect disposed at said first router that detects a failure in a light path between a first router in said first node and a first router in said second node, and reestablishes the light path by using a second router at said first node in place of said first router at said first node.