Dynamic division of routing domains in reactive routing networks

Abstract

In one embodiment, a reactive routing network may be dynamically divided into reactive routing network sub-domains that comprise a plurality of nodes having bounded route request (RREQ) scopes (e.g., search-domains) that are limited to a particular path length. The transit node in a first reactive routing network sub-domain may receive a RREQ from an originating node within the first reactive routing network sub-domain for a target node determined by the originating node to be beyond the bounded RREQ scope of the originating node. The transit node may then discover a route from the transit node to the target node, and return the route to the originating node. In this manner, the transit node may establish a complete route between the originating node and the target node.

What is claimed is: 
     
         1 . A method, comprising:
 receiving, at a transit node, a route request (RREQ) for a target node from an originating node within a first reactive routing network sub-domain, wherein the first reactive routing network sub-domain comprises a plurality of nodes having a bounded RREQ scope limited to a particular path length, and the target node is beyond the bounded RREQ scope of the originating node;   discovering a route from the transit node to the target node; and   returning the route to the originating node to establish a complete route between the originating node and the target node.   
     
     
         2 . The method as in  claim 1 , wherein the bounded RREQ scope is set by a segmentation message broadcast to the originating node. 
     
     
         3 . The method as in  claim 2 , wherein the segmentation message comprises a time-to-live indicator to be used in RREQs broadcast by the plurality of nodes within the first reactive routing network sub-domain. 
     
     
         4 . The method as in  claim 2 , further comprising:
 triggering broadcast of the segmentation message in response to control plane overhead of the reactive routing network exceeding a predetermined threshold value.   
     
     
         5 . The method as in  claim 2 , wherein the segmentation message comprises a time-to-live indicator which limits the plurality of nodes contacted by the segmentation message and define a boundary for the first reactive routing network sub-domain. 
     
     
         6 . The method as in  claim 1 , wherein the RREQ for the target node comprises the transit node as a first loose hop and the target node as a final loose hop. 
     
     
         7 . The method as in  claim 4 , wherein the segmentation message is broadcast in response to an instruction from a management device. 
     
     
         8 . The method as in  claim 1 , wherein discovering further comprises:
 multicasting the RREQ to one or more transit nodes in a reactive routing network.   
     
     
         9 . The method as in  claim 1 , wherein discovering further comprises:
 broadcasting the RREQ to a reactive routing network.   
     
     
         10 . The method as in  claim 1 , wherein discovering further comprises:
 identifying a route to the target node based on a route reply (RREP) received from a previous RREQ sent prior to the receiving step.   
     
     
         11 . The method as in  claim 1 , wherein the transit node is a border router for the first reactive routing network sub-domain, 
     
     
         12 . A method, comprising:
 receiving, at a node within a reactive routing network, a segmentation message;   establishing, in response to the segmentation message, a bounded route request (RREQ) scope for any RREQ originated by the node to cause each RREQ to be limited to a particular path length; and   forwarding at least one RREQ to a transit node for any target node not identified by the node as being within the bounded RREQ scope of the node.   
     
     
         13 . The method as in  claim 12 , wherein the segmentation message comprises a time-to-live indicator to be used in RREQs broadcast by a plurality of nodes within a first reactive routing network sub-domain. 
     
     
         14 . The method as in  claim 12 , wherein the segmentation message is received from the transit node. 
     
     
         15 . The method as in  claim 12 , wherein the node, having determined that the target node is not within the bounded RREQ scope, uses a proactive directed acyclic graph (DAG) to provide a route to the transit node, or broadcasts a RREQ to identify a route to the transit node. 
     
     
         16 . The method as in  claim 12 , wherein forwarding further comprises:
 setting the RREQ to indicate the transit node as the first loose hop and the target node as the final loose hop.   
     
     
         17 . The method as in  claim 12 , further comprising:
 receiving a route reply (RREP) from the transit node, the RREP indicating an entire path from the originating node to the target node via the transit node.   
     
     
         18 . The method as in  claim 12 , further comprising:
 receiving segmentation messages from two or more transit nodes; and   picking one particular transit node to receive forwarded RREQs.   
     
     
         19 . An apparatus, comprising:
 one or more network interfaces to communicate within a computer network;   a processor coupled to the network interfaces and adapted to execute one or more processes; and   a memory configured to store a process executable by the processor, the process when executed operable to:
 receive, as a transit node, a route request (RREQ) for a target node from an originating node within a first reactive routing network sub-domain, wherein the first reactive routing network sub-domain comprises a plurality of nodes having a bounded RREQ scope limited to a particular path length, and the target node is beyond the bounded RREQ scope of the originating node; 
 discover a route from the transit node to the target node; and 
 return the route to the originating node to establish a complete route between the originating node and the target node. 
   
     
     
         20 . The apparatus as in  claim 19 , wherein the process is configured to broadcast a segmentation message indicating the bounded RREQ scope. 
     
     
         21 . The apparatus as in  claim 20 , the segmentation message comprising a time-to-live indicator to be used in RREQs broadcast by the plurality of nodes within the first reactive routing network sub-domain. 
     
     
         22 . The apparatus as in  claim 20 , the segmentation message comprising a time-to-live indicator to limit the plurality of nodes contacted by the segmentation message and define a boundary for the first reactive routing network sub-domain. 
     
     
         23 . The apparatus as in  claim 19 , wherein the process when executed is further operable to:
 trigger broadcast of the segmentation message in response to control plane overhead of the reactive routing network exceeding a predetermined threshold value.   
     
     
         24 . An apparatus, comprising:
 one or more network interfaces to communicate within a computer network;   a processor coupled to the network interfaces and adapted to execute one or more processes; and   a memory configured to store a process executable by the processor, the process when executed operable to:
 receive, as a node within a reactive routing network, a segmentation message; 
 establish, in response to the segmentation message, a bounded route request (RREQ) scope for any RREQ originated by the node which is limited to a particular path length; and 
 forward RREQs to a transit node for any target node not identified by the node as being within the bounded RREQ scope of the node. 
   
     
     
         25 . The apparatus as in  claim 24 , wherein the segmentation message comprises a time-to-live indicator to be used in RREQs broadcast by a plurality of nodes within a first a reactive routing network sub-domain