Implicit shared bandwidth protection for fast reroute

A method for operating a data communication network to provide protection to nodes in said data communication network, said method comprising:

• maintaining, for each of a plurality of links in said data communication network, a primary bandwidth pool and a backup bandwidth pool;
• and
• establishing backup tunnels to protect a plurality of nodes of said network, each of said backup tunnels consuming backup bandwidth from backup bandwidth pools of selected ones of said plurality of links;
• and
• wherein all backup tunnels protecting any particular node of said network do not consume more bandwidth on any link than provided by the link's backup bandwidth pool but wherein there is at least one set of backup tunnels that protect disparate nodes and that consume more bandwidth on at least one link than provided by said at least one link's backup bandwidth pool.

In a data communication network, apparatus for protecting a node, said apparatus comprising:

• means for establishing a backup bandwidth pool on links of said data communication network;
• means for identifying a link pair traversing said node, said link pair having a bandwidth to be protected;
• means for establishing as a backup for said link pair a set of one or more paths that do not include said node wherein said one or more paths collectively have backup bandwidth greater than or equal to said bandwidth to be protected;
• means for deducting, for each link included in said set of paths, from backup bandwidth available for protecting said node while not deducting from backup bandwidth available for protecting other nodes in said data communication network;
• and
• means for repeatedly invoking said means for identifying, establishing, and deducting, for a plurality of link pairs connected to said node without exceeding available backup bandwidth of links used in an establishing said backups.

Apparatus for operating a data communication network to provide protection to nodes of said data communication network, said apparatus comprising:

• means for maintaining, for each of a plurality of links in said data communication network, a primary bandwidth pool and a backup bandwidth pool;
• and
• means for establishing backup tunnels to protect a plurality of nodes of said network, each of said backup tunnels reserving backup bandwidth from backup bandwidth pools of selected ones of said plurality of links;
• and
• wherein all backup tunnels protecting any particular node of said network do not consume more bandwidth on any link than provided by the link's backup bandwidth pool but wherein there is at least one set of backup tunnels that protect disparate nodes and that consume more bandwidth on at least one link than provided by said at least one links backup bandwidth pool.

In a data communication network, a computer program product for protecting a node, said computer program product comprising:

• code that establishes a backup bandwidth pool on links of said data communication network;
• code that identifies a link pair traversing said node, said link pair having a bandwidth to be protected;
• code that establishes a backup for said link pair a set of one or more paths that do not include said node and wherein one or more paths collectively have backup bandwidth greater than or equal to said bandwidth to be protected;
• code that deducts, for each link included in said set of paths, from backup bandwidth available for protecting said node, while not deducting from backup bandwidth available for protecting other nodes in said data communication network;
• code that repeatedly invokes said code that identifies, establishes, and deducts for a plurality of link pairs connected to said node without exceeding available backup bandwidth of links used in establishing said backups;
• and
• a computer-readable storage medium that stores the codes.

A computer program product for operating a data communication network to provide protection to nodes in the data communication network, said computer program product comprising:

• code that maintains, for each of a plurality of links in said data communication network a primary bandwidth pool and a backup bandwidth pool;
• and
• code that establishes backup tunnels to protect a plurality of nodes of said network, each of said backup tunnels reserving backup bandwidth from backup bandwidth pools of selected ones of said plurality of links;
• wherein all backup tunnels protecting any particular node of said network do not consume more bandwidth on any link than provided by the link's backup bandwidth pool but wherein there is at least one set of backup tunnels that protect disparate nodes and that consume more bandwidth on at least one link than provided by said at least one link's backup bandwidth pool;
• and
• a computer-readable storage medium that stores the codes.

A network device for implementing a node in a data communication network, said network device comprising:

• a processor;
• and
• a memory storing instruction for said processor, said instructions comprising:
• code that establishes a backup bandwidth pool on links of said data communication network;
• code that identifies a link pair traversing said node, said link pair having a bandwidth to be protected;
• code that establishes a backup for said link pair a set of one or more paths that do not include said node and wherein one or more paths collectively have backup bandwidth greater than or equal to said bandwidth to be protected;
• code that deducts, for each link included in said set of paths, from backup bandwidth available for protecting said node, while not deducting from backup bandwidth available for protecting other nodes in said data communication network;
• and
• code that repeatedly invokes said code that identifies, establishes, and deducts for a plurality of link pairs connected to said node without exceeding available backup bandwidth of links used in establishing said backups.

A network device for implementing a node in a communication network, said network device comprising:

• a processor;
• and
• a memory storing instruction for said processor, said instructions comprising:
• code that establishes backup tunnels to protect a plurality of nodes of said network, each of said backup tunnels reserving backup bandwidth from backup bandwidth pools of selected ones of said plurality of links;
• wherein all backup tunnels protecting any particular node of said network do not consume more bandwidth on any link than provided by the link's backup bandwidth pool but wherein there is at least one set of backup tunnels that protect disparate nodes and that consume more bandwidth on at least one link than provided by said at least one link's backup bandwidth pool.

A computer program product for protecting a node in a data communication network, said computer program product comprising:

• code that performs computations at said node to identify backup tunnels to protect said node;
• code that signals said backup tunnels to other nodes of said data communication network;
• and
• a computer-readable storage medium that stores the codes.

A network device that implements a node in a data communication network, said network device comprising:

• a processor;
• a memory device storing instructions for said processor, said instructions comprising:
• code that performs computations at said node to identify backup tunnels to protect said node;
• and
• code that signals said backup tunnels to other nodes of said data communication network.