System and methods for detecting network failure

A method of identifying network failure comprising:

• periodically transmitting diagnostic messages to a plurality of predetermined routing points along a path to a destination;
• transmitting, if the diagnostic messages indicate a problem with intermediate nodes along the path, a series of path verification messages, each of the path verification messages including a command operable to direct an intermediate node to transmit a further message to a successive intermediate node in the path, receive the result from the further message, and report the result as a command response, the result indicative of reachability of the successive intermediate node;
• repeating the transmission of path verification messages to successive nodes along the path to the node indicating the problem;
• analyzing the received command responses from the successive path verification messages to identify problems;
• determining an alternate route based on the analyzing to bypass the intermediate node identified as a source of the indicated problem;
• wherein transmitting further comprises:
• transmitting a plurality of path verification messages to a plurality of predetermined network points according to a diagnostic protocol;
• receiving command responses corresponding to the transmitted path verification messages, the command responses including a test result according to the diagnostic protocol;
• and
• tracking the command responses received from each of the plurality of path verification messages transmitted along a path from a source to a destination.

A method of identifying network failure comprising:

• periodically transmitting diagnostic messages to a plurality of predetermined routing points along a path to a destination;
• transmitting, if the diagnostic messages indicate a problem with intermediate nodes along the path, a series of path verification messages, each of the path verification messages including a command operable to direct an intermediate node to transmit a further message to a successive intermediate node in the path, receive the result from the further message, and report the result as a command response, the result indicative of reachability of the successive intermediate node;
• repeating the transmission of path verification messages to successive nodes along the path to the node indicating the problem;
• analyzing the received command responses from the successive path verification messages to identify problems, wherein analyzing further comprises identifying a forwarding plane error indicative of inability of message propagation along a purported optimal path, and determining an alternate route based on the analyzing to bypass the intermediate node identified as a source of the indicated problem, wherein determining comprises changing a control plane routing decision corresponding to the purported operational path.

A method for locating network failures comprising:

• transmitting a plurality of path verification messages to a plurality of predetermined network points according to a diagnostic protocol;
• receiving command responses corresponding to the transmitted path verification messages, the responses including a test result according to the diagnostic protocol;
• tracking the command responses received from each of the plurality of path verification messages transmitted along a path from a source to a destination;
• and
• concluding, based on the receipt of responses from the predetermined network points, alternate routing paths for message traffic in the network.

A method for locating a deficient network interconnection comprising:

• identifying a path from a data communication device to a remote network destination, the path further including a plurality of segments, each segment delimited by a hop;
• identifying the failure point comprising identifying a segment order defined by a path to the destination;
• iteratively transmitting a probe to each successive hop along the ordered path;
• concluding, if a probe response returns with respect to a particular hop, that the path is unobstructed up to the hop corresponding to the returned probe;
• concluding, if the probe response is not received for a particular probe, that an obstruction exists between the hop corresponding to the particular probe and previous hop;
• identifying, based on the hop corresponding to the concluded obstruction, an alternate path;
• and
• determining, based on the identified alternate path, whether to direct message traffic to the identified alternate path.

A method for network failure location identification comprising:

• enumerating a set of significant routes, the significant routes carrying a substantial traffic load over a critical path;
• identifying active routes from the significant routes based on recently carried traffic;
• determining, for each of the identified active routes, whether an unobstructed network path exists;
• applying, for each active route determined to have an obstruction, a path verification to identify a path segment corresponding to a point of obstruction, the path verification process further comprising:
• pinging each of a plurality of intermediate hops;
• identifying hops for which the ping response is deficient;
• repinging, if the ping response was deficient, the hop after waiting for a convergence threshold delay;
• concluding, if the response to the repining is received, a core network failure which has been rerouted around;
• and
• determining if the repinging response is not received, a failure at a point between the repinged hop and the previous hop.

A data communications device for identifying network failure comprising:

• a memory operable to store instructions and data;
• an execution unit coupled to the memory, the execution unit in communication with the data and responsive to the instructions;
• a network interface coupled to other data communications devices;
• a path verification processor in the execution unit operable to periodically transmit diagnostic messages, via the network interface, to a plurality of predetermined routing points along a path to a destination, and further operable to transmit, if the diagnostic message indicate a problem with intermediate nodes along the path, a series of path verification messages, each of the path verification messages including a command operable to:
• direct an intermediate node to transmit a further message to a successive intermediate node in the path;
• receive the result from the further message;
• and
• report the result as a command response, the result indicative of reachability of the successive intermediate node, the path verification processor further operable to:
• repeat the transmission of path verification messages to successive nodes along the path to the node indicating the problem;
• and
• analyze the received command responses from the successive path verification messages to identify problems;
• and
• routing logic in the memory and responsive to the path verification processor and operable determining an alternate route based on the analyzing to bypass the intermediate node identified as a source of the indicated problem.

A computer program product having a computer readable storage medium operable to store computer program logic embodied in computer program code, the computer program code executable with a processor to identify network failure, the computer readable storage medium comprising:

• computer program code executable to periodically transmit diagnostic messages to a plurality of predetermined routing points along a path to a destination;
• computer program code executable to transmit, if the diagnostic message indicate a problem with intermediate nodes along the path, a series of path verification messages, each of the path verification messages including a command operable to direct an intermediate node to transmit a further message to a successive intermediate node in the path, receive the result from the further message, and report the result as a command response, the result indicative of reachability of the successive intermediate node;
• computer program code executable to repeat the transmission of path verification messages to successive nodes along the path to the node indicating the problem;
• computer program code executable to analyze the received command responses from the successive path verification messages to identify problems;
• and
• computer program code executable to determine an alternate route based on the analyzing to bypass the intermediate node identified as a source of the indicated problem.