VP protection system and VP protection method

A VP protection system which restores VPs (Virtual Paths) when an error occurs on an ATM (Asynchronous Transfer Mode) network, the system comprising:

• a first node in a stand by path including a unit which allocates resource information on a plurality of working VP groups for management of resources on a group basis and
• wherein, when a plurality of particular VPs are switched to standby VPs due to an error in the plurality of particular VPs said first node allocates resources for the group of the plurality of particular VPs in response to a grouped VP switching request message and forwards the grouped VP switching request message to a next node;
• and
• wherein said first node forwards a switching-response message to the next node without checking that a resource distribution unit has completed resource distribution to the VPs in said first node.

A VP protection method for restoring VPs (Virtual Paths) when an error occurs in an ATM (Asynchronous Transfer mode) network, the method comprising the steps of:

• in at least a first node in a standby path, allocating resource information on a plurality of working VP groups for management of resources on a group basis;
• when a group of plurality of particular VPs, are switched to standby VPs due to an error in the plurality of particular VPs allocating resources for the group of the plurality of particular VPs in response to a grouped VP switching request message and forwarding the grouped VP switching request message to a next node;
• and
• wherein, after the resources of the group of the plurality of particular VPs are allocated, the first node forwards the switching request message to the next node and, at substantially the same time, expands the group of the plurality of particular VPs into VPs and distributes resources to the VPs.

A computer program stored on a storage medium including data for restoring VPs (Virtual Paths) when an error occurs on an ATM (Asynchronous Transfer Mode) network, wherein the program causes the computer to:

• in at least a first node in a standby path, allocating resource information on a plurality of working VP groups for management of resources on a group basis;
• when a group of a plurality of particular VPs, are switched to standby VPs due to an error in the plurality of particular VPs allocating resources for the group of the plurality of particular VPs in response to a grouped VP switching request message and forwarding the grouped VP switching request message to a next node;
• and
• wherein, after the resources of the group of the plurality of particular VPs are allocated, the first node forwards the switching request message to the next node and, at substantially the same time, expands the group of the plurality of particular VPs into VPs and distributes resources to the VPs.

A VP protection system, for use on an ATM network comprising:

• a plurality of ATM nodes;
• a plurality of working VPs used as information transmission paths among said plurality of nodes;
• a plurality of standby VPs used as bypass paths when an error occurs on said working VPs, wherein, when said plurality of working VPs are switched to the corresponding standby VPs upon detection of the error on said plurality of working VPs, messages are exchanged among said ATM nodes with CP groups each including a plurality of VPs each of said ATM nodes comprising:
• a VPG resource information management table which stores therein an amount of resource requirements for a virtual path group;
• a VP resource information management table which stores therein an amount of resource requirements for each VP;
• a VPG configuration information management table which stores therein information for identifying the VPs forming the VPG;
• a VPG switching message receiving circuit which receives 20 a VPG switching request message or a VPG switching response message transferred between endpoint nodes in a switching section;
• a VPG switching message sending circuit which sends the VPG switching request message or the VPG switching response message transferred between the endpoint nodes in the switching section to another node;
• one or more node resource management circuits which allocate node resources or network resources in a particular node in response to a request generated in the particular node;
• a VPG resource allocation circuit which references said VPG resource information management table to allocate the node resources and the network resources to the VPG in response to said VPG switching request message;
• a VP expansion circuit which expands the VPG into individual VPs;
• and
• a VP resource distribution circuit which references said VP resource information management table and distributes the VPG resources allocated by said VPG resource allocation circuit to the individual VPs expanded by said VP expansion circuit.