Loopback capability for Bi-directional multi-protocol label switching traffic engineered trunks

Abstract

A system and method for introducing a loopback capability for Multi-Protocol Label Switching (MPLS) bi-directional traffic trunks are discussed. MPLS is an emerging technology, which integrates Internet Protocol (IP) routing with label switching techniques. MPLS intends to provide new capabilities in the area of traffic engineering for IP networks. These traffic engineering capabilities will have to be combined with a set of complementary operation, administration and maintenance (OA&M) functions for effectively managing and operating MPLS-based networks. One such function is loopback. A loopback function provides the capability to transmit a OA&M packet on one or more segments of a bi-directional traffic trunk (BTT) in a MPLS network. Using a loopback function, parameters of a BTT, such as connectivity, delay and other Quality of Service (QoS) parameters, can be tested. The system and method provide different techniques for implementing loopback in an MPLS network.

1 . A method comprising steps of: 
 establishing a bi-directional traffic trunk; and    performing a loopback function on the established bi-directional traffic trunk.    
     
     
         2 . The method of  claim 1 , further comprising a step of: 
 evaluating at least one parameter of the established bi-directional traffic trunk using the performed loopback function.    
     
     
         3 . The method of  claim 2 , further comprising a step of: 
 activating the established bi-directional traffic trunk, when the evaluated parameter is any one of (1) equivalent to a predetermined standard associated with the evaluated parameter and (2) exceeds the predetermined standard associated with the evaluated parameter.    
     
     
         4 . The method of  claim 3 , further comprising steps of: 
 performing at least one of (1) re-establishing the bi-directional traffic trunk using a different explicit route and (2) providing notification, when the evaluated parameter is not equivalent to and does not exceed the predetermined standard.    
     
     
         5 . The method of  claim 2 , further including a step of: 
 deactivating the loopback procedure, when the evaluated parameter is any one of (1) equivalent to a predetermined standard associated with the evaluated parameter and (2) exceeds the predetermined standard associated with the evaluated parameter.    
     
     
         6 . The method of  claim 2 , wherein the evaluated parameter includes at least one of connectivity, delay and other quality of service parameters.  
     
     
         7 . The method of  claim 3 , further comprising steps of: 
 performing the loopback function for the activated bi-directional traffic trunk; and    evaluating at least one parameter for the activated bi-directional traffic trunk using the performed loopback function.    
     
     
         8 . The method of  claim 7 , wherein the loopback function for the activated bi-directional traffic trunk is performed periodically, and the evaluated parameter for the activated bi-directional traffic trunk is evaluated periodically.  
     
     
         9 . The method of  claim 8 , further comprising steps of: 
 performing at least one (1) re-establishing the bi-directional traffic trunk using a different explicit route and (2) providing notification, when the evaluated parameter for the activated bi-directional trunk is not equivalent to and does not exceed a predetermined standard associated with the evaluated standard.    
     
     
         10 . The method of  claim 9 , wherein the parameter evaluated for the activated bi-directional traffic trunk includes at least one of connectivity, delay and other quality of service parameters.  
     
     
         11 . The method of  claim 1 , further including steps of: 
 selecting a label switching router in a path traversed by the bi-directional traffic trunk; and    activating a loopback procedure at the label switching router.    
     
     
         12 . A method of  claim 2 , wherein the evaluated parameter is evaluated for at least one portion of the established bi-directional traffic trunk.  
     
     
         13 . A method comprising steps of: 
 activating a bi-directional traffic trunk; and    performing a loopback function on the activated bi-directional traffic trunk.    
     
     
         14 . The method of  claim 13 , further comprising a step of: 
 evaluating at least one parameter of the established bi-directional traffic trunk using the performed loopback function.    
     
     
         15 . The method of  claim 14 , wherein the loopback function for the activated bi-directional traffic trunk is performed periodically, and the evaluated parameter for the activated bi-directional traffic trunk is evaluated periodically.  
     
     
         16 . The method of  claim 14 , further comprising steps of: 
 performing at least one of (1) re-establishing the bi-directional traffic trunk using a different explicit route and (2) providing notification, when the evaluated parameter for the activated bi-directional traffic trunk is not equivalent to and does not exceed a predetermined standard associated with the evaluated parameter.    
     
     
         17 . The method of  claim 14 , wherein the at least one parameter includes at least one of connectivity, delay and other quality of service parameters.  
     
     
         18 . A network comprising: 
 an originating router configured to transmit a packet downstream on a bi-directional traffic trunk; and    a loopback router configured to receive the packet and transmit the packet upstream towards the originating router on the bi-directional traffic trunk.    
     
     
         19 . The network of  claim 18 , wherein the originating router receives the packet from the loopback router and evaluates at least one parameter of the bi-directional traffic trunk using the packet.  
     
     
         20 . The network of  claim 19 , wherein the bi-directional traffic trunk is not activated.  
     
     
         21 . The network of  claim 20 , wherein the originating router performs at least one of (1) re-establishing the bi-directional traffic trunk using a different explicit route and (2) providing notification, when the evaluated parameter is not equivalent to and does not exceed a predetermined standard associated with the evaluated parameter.  
     
     
         22 . The network of  claim 20 , wherein the originating router activates the established bi-directional traffic trunk, when the evaluated parameter is any one of (1) equivalent to a predetermined standard associated with the evaluated parameter and (2) exceeds a predetermined standard associated with the evaluated parameter.  
     
     
         23 . The network of  claim 20 , wherein the parameter is evaluated for at least one portion of the bi-directional traffic trunk.  
     
     
         24 . The network of  claim 19 , wherein the bi-directional traffic trunk is activated.  
     
     
         25 . The network of  claim 24 , wherein the originating router performs at least one of (1) re-establishing the bi-directional traffic trunk using a different explicit route and (2) providing notification, when the evaluated parameter for the activated bi-directional traffic trunk is not equivalent to and does not exceed a predetermined standard associated with the evaluated parameter.  
     
     
         26 . The network of  claim 19 , wherein the at least one parameter includes at least one of connectivity, delay and other quality of service.  
     
     
         27 . A method comprising steps of: 
 receiving a packet traveling downstream on a bi-directional traffic trunk; and    transmitting the received packet upstream on the bi-directional traffic trunk.    
     
     
         28 . The method of  claim 27 , further comprising a step of identifying the incoming label of the received packet.  
     
     
         29 . The method of  claim 28 , further comprising a step of replacing the identified incoming label with an incoming label corresponding to a received packet travelling upstream on the bi-directional traffic trunk.  
     
     
         30 . The method of  claim 29 , further comprising steps of: 
 maintaining a table of next hop label forwarding entries; and    determining the received packet's next hop using a next hop label forwarding entry associated with the replaced incoming label.    
     
     
         31 . The method of  claim 27 , wherein the step of receiving a packet further includes receiving the packet at a label switching router, and the receiving label switching router is any one of a label edge router and an intermediate label switching router.  
     
     
         32 . The method of  claim 27 , wherein the bi-directional traffic trunk is in a multi-protocol label switching network.  
     
     
         33 . A router comprising: 
 a plurality of ports, one port of the plurality of ports receiving a packet travelling downstream on a bi-directional traffic trunk; and    processing circuitry processing the packet and forwarding the packet to a selected port of the plurality of ports for transmission to a next hop upstream on the bi-directional traffic trunk.    
     
     
         34 . A method comprising steps of: 
 constructing a packet at a router;    transmitting the packet downstream on a bi-directional traffic trunk from the router constructing the packet;    receiving the packet at a router; and    determining whether to perform a loopback procedure at the router receiving the packet.    
     
     
         35 . The method of  claim 34 , further comprising a step of: 
 identifying the received packet as a loopback packet.    
     
     
         36 . The method of  claim 35 , further comprising a step of: 
 processing the received packet in accordance with a command in the packet, when the packet is determined to be a loopback packet    
     
     
         37 . The method of  claim 36 , wherein the command is associated with at least one parameter of the bi-directional traffic trunk.  
     
     
         38 . The method of  claim 37 , wherein the at least one parameter includes at least one of connectivity, delay, and other quality of service parameters.  
     
     
         39 . The method of  claim 34 , wherein the router constructing the packet and the router receiving the packet are label switching routers.  
     
     
         40 . The method of  claim 34 , wherein the step of determining whether to perform a loopback procedure further includes a step of determining whether the received packet is a loopback packet.  
     
     
         41 . The method of  claim 40 , wherein the step of determining whether to perform a loopback procedure further includes a step of determining whether the router receiving the packet is a loopback router for the received packet.  
     
     
         42 . The method of  claim 38 , further comprising a step of: 
 transmitting the received packet to a next hop downstream on the bi-directional traffic trunk, when the received packet is not a loopback packet.    
     
     
         43 . The method of  claim 39 , further comprising a step of: 
 transmitting the received packet to a next hop downstream on the bi-directional traffic trunk, when the router receiving the packet is not the loopback router for the received packet.    
     
     
         44 . A network comprising: 
 a bi-directional traffic trunk;    an originating router constructing a packet and transmitting a packet downstream on the bi-directional traffic trunk; and    a receiving router receiving the packet and determining whether the receiving router is a loopback router for the received packet.    
     
     
         45 . The network of  claim 44 , wherein the receiving router performs a loopback procedure, when the receiving router is the loopback router for the received packet.  
     
     
         46 . The network of  claim 45 , wherein the receiving router processes the received packet in accordance with a command in the packet.  
     
     
         47 . The network of  claim 46 , wherein the command is associated with at least one parameter of the bi-directional traffic trunk.  
     
     
         48 . The network of  claim 47 , wherein, the at least one parameter includes at least one of connectivity, delay, and other quality of service parameters.  
     
     
         49 . The network of  claim 45 , wherein the receiving router transmits the received packet to a next hop upstream, towards the originating router, when the receiving router is the loopback router for the received packet.  
     
     
         50 . The network of  claim 44 , wherein the receiving router transmits the received packet to a next hop downstream on the bi-directional traffic trunk, when the receiving router is not the loopback router for the received packet.  
     
     
         51 . The network of  claim 44 , wherein the originating router and the receiving routers are label switching routers.