Communication network system, path calculation device, and communication path establishment control method

Abstract

In an MPLS or GMPLS network, links for hops of a communication path and adaptation to be implemented on the border of management domains or layers are automatically appropriately selected based on a service type or a requirement for maintenance without the necessity of complicating a control sequence. First, a unit that appends an identifier of a service to be provided and an attribute of the service to a communication path establishment control message, and requests path establishment is installed in a source node. Secondly, a unit that determines a requirement for maintenance of the communication path and adaptation on the basis of the service identifier and/or service attribute is installed in each node. Thirdly, maintenance attributes of network resources are compared with the requirement for maintenance in order to determine links and nodes through which the communication path passes.

1 . (canceled) 
     
     
         2 . A network system comprising a plurality of nodes and a path calculation device:
 the path calculation device includes:
 a service definition table in which a service identifier, a service attribute, and a requirement for maintenance of communication path are recorded in association with one another, and 
 a link attribute table in which a link identifier of a link and a maintenance attribute of the link are recorded in association with each other; wherein: 
   the path calculation device uses the service definition table to determine the requirement for maintenance, which links for hops of a communication path to be established should satisfy, on the basis of the service identifier and service attribute;   the path calculation device extracts a plurality of links, of which maintenance attributes satisfy the determined requirement for maintenance, from the link attribute table, and determines a candidate for a route of the communication path, which satisfies the requirement for maintenance in relation to each of the hops, in a network formed with the extracted plurality of links;   the path calculation device sets up a route to the plurality of nodes on the basis of the determined candidate for the route; and   the node sets up the route on the basis of route information which is received from the path calculation device.   
     
     
         3 . The network system according to  claim 2 , wherein:
 the network system is configured by multiple management domains and/or multiple layers;   the node has an adaptation function which can be controlled for each communication path established between the management domains and/or the layers;   the path calculation device determines an adaptation information, which is any of various connection facilities to be implemented at the end point of the path, by searching the service definition table on the basis of the service identifier and service attribute, and notifies the node of the determined candidate for the route and/or the adaptation information; and   the node configures the adaptation function based on the received adaptation information.   
     
     
         4 . The network system according to  claim 3 , wherein:
 the network system further includes a second path calculation device; and   the path calculation device includes means that requests the second path calculation device to determine a detailed route of a path and/or adaptation in relation to a portion of an interval for which path calculation has been requested, receives a response, and produces a response to a path calculation request, which the path calculation device has received, by inserting the route and/or adaptation information, which are contained in the received response, to a part of the route of the path and adaptation information, which are determined by the path calculation device, relating to the portion of the interval.   
     
     
         5 . The network system according to  claim 4 , wherein an adaptation facility represented by the adaptation information includes one or more of an encapsulation function, a function of distributing a flow or integrating portions of a flow, and a function of selectively transferring a management alarm, which are applied to data to be transferred from the node. 
     
     
         6 . The network system according to  claim 5 , wherein the adaptation facility represented by the adaptation information includes a QoS mapping function and/or a code conversion function, which are applied to data to be transferred from the node. 
     
     
         7 . The network system according to  claim 3 , wherein the requirement for maintenance of the communication path and the maintenance attributes of the network resources each include information on a time zone during which a service should be provided, and/or information on the length of a time during which discontinuation of a service is permitted. 
     
     
         8 . The network system according to  claim 4 , wherein, if a source of the path calculation request is the path calculation device, the second path calculation device determines an adaptation ticket that is a tag assigned to the adaptation information instead of the adaptation itself, and returns as a path calculation response message. 
     
     
         9 . The network system according to  claim 4 , wherein:
 the path calculation device transmits the path calculation request to a TDM-layer path calculation device, the path calculation request to which the service identifier and service attribute are appended.   
     
     
         10 . A network method in a network system comprising a plurality of nodes and a path calculation device:
 the path calculation device includes:
 a service definition table in which a service identifier, a service attribute, and a requirement for maintenance of communication path are recorded in association with one another, and 
 a link attribute table in which a link identifier of a link and a maintenance attribute of the link are recorded in association with each other; wherein: 
   the path calculation device uses the service definition table to determine the requirement for maintenance, which links for hops of a communication path to be established should satisfy, on the basis of the service identifier and service attribute;   the path calculation device extracts a plurality of links, of which maintenance attributes satisfy the determined requirement for maintenance, from the link attribute table, and determines a candidate for a route of the communication path, which satisfies the requirement for maintenance in relation to each of the hops, in a network formed with the extracted plurality of links;   the path calculation device sets up a route to the plurality of nodes on the basis of the determined candidate for the route; and   the node sets up the route on the basis of route information which is received from the path calculation device.   
     
     
         11 . The network method according to  claim 10 , wherein:
 the network system is configured by multiple management domains and/or multiple layers;   the node has an adaptation function which can be controlled for each communication path established between the management domains and/or the layers;   the path calculation device determines an adaptation information, which is any of various connection facilities to be implemented at the end point of the path, by searching the service definition table on the basis of the service identifier and service attribute, and notifies the node of the determined candidate for the route and/or the adaptation information; and   the node configures the adaptation function based on the received adaptation information.   
     
     
         12 . A path calculation device in a network system comprising a plurality of nodes and the path calculation device, including:
 a service definition table in which a service identifier, a service attribute, and a requirement for maintenance of communication path are recorded in association with one another, and   a link attribute table in which a link identifier of a link and a maintenance attribute of the link are recorded in association with each other; wherein:   the path calculation device uses the service definition table to determine the requirement for maintenance, which links for hops of a communication path to be established should satisfy, on the basis of the service identifier and service attribute;   the path calculation device extracts a plurality of links, of which maintenance attributes satisfy the determined requirement for maintenance, from the link attribute table, and determines a candidate for a route of the communication path, which satisfies the requirement for maintenance in relation to each of the hops, in a network formed with the extracted plurality of links; and   the path calculation device sets up a route to the plurality of nodes on the basis of the determined candidate for the route.   
     
     
         13 . The path calculation device according to  claim 12 , wherein the path calculation device determines an adaptation information, which is any of various connection facilities to be implemented at the end point of the path, by searching the service definition table on the basis of the service identifier and service attribute, and notifies the node of the determined candidate for the route and/or the adaptation information.