System and methods for network reachability detection
First Claim
1. A method of assessing a state of a remote node via a label switched path, the method comprising:
- receiving a response request message from an originator node at an autonomous system border router, the autonomous system border router included in a plurality of autonomous system border routers on the label switched path between the originator node and the remote node;
transmitting the response request message to each successive one of the autonomous system border routers as the response request message traverses the autonomous system border routers on the label switched path to the remote node;
accumulating, in a nondestructive manner at each successive one of the autonomous system border routers, an entry indicative of an identity of each successive one of the autonomous system border routers traversed on the label switched path to the remote node, wherein accumulating the entry indicative of the identity of each successive one of the autonomous system border routers further comprises building a stack of accumulated entries indicative of identities of the autonomous system border routers in the response request message;
traversing the label switched path back to the originator node based on the stack of accumulated entries included in the acknowledgement response message; and
forwarding messages at each respective one of the autonomous system border routers according to forwarding rules, the forwarding rules directing the respective one of the autonomous system border routers to;
transmit the response request message, if the response request message is received, to a next route toward the remote node;
redirect the acknowledgment response message, if the acknowledgment response message is received, to a next address on the stack of accumulated entries; and
identify, if the response request message cannot reach the remote node, an autonomous system or the respective one of the autonomous system border routers encountering a condition of the response request message being unable to reach the remote node.
2 Assignments
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Accused Products
Abstract
A mechanism for ASBRs to identify the originating node, or router, in an LSP conversant autonomous system (AS), such as an MPLS VPN environment, maintains the identity of the originating node and successive nodes in subsequent autonomous systems along the path to the node to be pinged. The identity of the transporting nodes is stored in a stack or other object associated with the ping request (ping), such that the pinged node may employ the stored identity as a set of return path routing information. Successive ASBRs store their identity on the stack, in an ordered manner, along the path to the destination. Upon reaching the destination (ping) node, the destination node employs the identity of the first node on the stack to send the acknowledgment, or ping response. Each successive ASBR, therefore, pops (retrieves) the next node identity from the stack and redirects (sends) the ping response to the retrieved node.
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Citations
24 Claims
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1. A method of assessing a state of a remote node via a label switched path, the method comprising:
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receiving a response request message from an originator node at an autonomous system border router, the autonomous system border router included in a plurality of autonomous system border routers on the label switched path between the originator node and the remote node; transmitting the response request message to each successive one of the autonomous system border routers as the response request message traverses the autonomous system border routers on the label switched path to the remote node; accumulating, in a nondestructive manner at each successive one of the autonomous system border routers, an entry indicative of an identity of each successive one of the autonomous system border routers traversed on the label switched path to the remote node, wherein accumulating the entry indicative of the identity of each successive one of the autonomous system border routers further comprises building a stack of accumulated entries indicative of identities of the autonomous system border routers in the response request message; traversing the label switched path back to the originator node based on the stack of accumulated entries included in the acknowledgement response message; and forwarding messages at each respective one of the autonomous system border routers according to forwarding rules, the forwarding rules directing the respective one of the autonomous system border routers to; transmit the response request message, if the response request message is received, to a next route toward the remote node; redirect the acknowledgment response message, if the acknowledgment response message is received, to a next address on the stack of accumulated entries; and identify, if the response request message cannot reach the remote node, an autonomous system or the respective one of the autonomous system border routers encountering a condition of the response request message being unable to reach the remote node. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A data communications device for performing ping operations between autonomous system border routers (ASBRs) using label switched path (LSP) routing comprising:
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a network interface operable to identify a remote node from which an acknowledging response is requested, the remote node corresponding to a label switched path, wherein the label switched path includes the ASBRs; a return address stack operable to store an entry indicative of an identity of an originator node of a response request message; a routing processor operable to forward messages in accordance with forwarding rules, wherein the forwarding rules direct the routing processor to; to transmit the response request message, if the response request message is received, from any one of the ASBRs to a next respective one of the ASBRs on the label switched path toward the remote node; accumulate, in a nondestructive manner at each successive one of the ASBRs, a stack of accumulated entries indicative of an identity of each successive one of the ASBRs traversed on the label switched path to the remote node by the response request message, wherein the stack of accumulated entries is for inclusion in an acknowledgement response message; forward the acknowledgement response message, if the acknowledgement response message is received, toward the originator node based on the stack of accumulated entries; and identify, if the response request message cannot reach the remote node, an autonomous system or one of the ASBRs encountering a condition of the response request message being unable to reach the remote node. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A computer program product having a non-transitory computer readable medium operable to store computer program logic embodied in computer program code encoded thereon for assessing the state of a remote node via a labeled switch path comprising:
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computer code for receiving a response request message from an originator node at an autonomous system border router, the autonomous system border router included in a plurality of autonomous system border routers on the label switched path between the originator node and the remote node; computer code for transmitting the response request message to each successive one of the autonomous system border routers as the response request message traverses the autonomous system border routers on the label switched path to the remote node; computer code for accumulating, in a nondestructive manner at each successive one of the autonomous system border routers, an entry indicative of an identity of each successive one of the autonomous system border routers traversed on the label switched path to the remote node, wherein accumulating the entry indicative of the identity of each successive one of the autonomous system border routers further comprises building a stack of accumulated entries indicative of identities of the autonomous system border routers in the response request message; computer code for traversing the label switched path back to the originator node based on the stack of accumulated entries included in the acknowledgement response message; and computer code for forwarding messages at each respective one of the autonomous system border routers according to forwarding rules, the forwarding rules directing the respective one of the autonomous system border routers to; transmit the response request message, if the response request message is received, to a next route toward the remote node; redirect the acknowledgment response message, if the acknowledgment response message is received, to a next address on the stack of accumulated entries; and identify, if the response request message cannot reach the remote node, an autonomous system or the respective one of the autonomous system border routers encountering a condition of the response request message being unable to reach the remote node.
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24. A data communications device for performing ping operations between autonomous system border routers (ASBRs) using label switched path (LSP) routing comprising:
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means for identifying a remote node from which an acknowledging response is requested, the remote node corresponding to a label switch path, the label switched path including a sequence of border routers; means for storing an entry indicative of an identity of an originator node of an acknowledging response request in a response request message; means for receiving, from the originator node, the response request message at a border router included on the label switched path to the remote node; means for transmitting the response request message to successive border routers on the label switched path to the remote node, wherein each one of the successive border routers forwards the response request message to a next one of the successive border routers; means for accumulating, in a nondestructive manner at each successive border router, an entry indicative of an identity of each one of the successive border routers on the label switched path to the remote node, the accumulated entries indicative of the successive border routers stored on a stack; means for coupling to a plurality of subnetworks defined by border routers indicative of ingress points to the respective subnetwork, each of the subnetworks being an autonomous system having an independent routing policy; means for forwarding to the plurality of subnetworks, the forwarding occurring according to forwarding rules, the forwarding rules further including rules to; transmit, if an acknowledgment request is received, to a next route toward the remote node defining a ping destination; redirect toward the originator node, if an acknowledgment response is received, to the next address on the stack of the accumulated entries, the acknowledgement response; and identify, if the remote node cannot be reached, an autonomous system encountering a condition of the response request message being unable to reach the remote node.
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Specification