Capacity variable link apparatus and capacity variable link setting method

Abstract

A capacity variable link apparatus including a main signal system and a control signal system is provided. The main signal system includes: an upper layer signal accommodation part; a lower layer path termination part; and a signal switching part for dividing the upper layer signal to lower layer signals in a lower layer path group having a capacity that is determined according to an amount of traffic of the upper layer signal. The control system includes: a traffic amount measuring part for measuring the amount of traffic of the upper layer and for determining whether the capacity of the lower layer path group is to be increased or decreased according to the amount; and a signal switching management part for controlling the signal switching part according to the result of the determination.

1 . A capacity variable link setting method in a hierarchical network in which a link in an upper layer is formed by a path group of a lower layer,
 wherein said hierarchical network includes node apparatus comprising means for editing an upper layer signal so as to divide said upper layer signal into each path in said path group in the lower layer, said capacity variable link setting method comprising:   a traffic data obtaining step of obtaining traffic data of said upper layer;   an increase/decrease determination step of determining increase or decrease of a lower layer path by using said traffic data;   an increase/decrease step in which, when it is determined that said lower layer path is to be increased or decreased, said node apparatus sends a request for increasing or decreasing said lower layer path from the upper layer to the lower layer, and said lower layer path is set up between said node apparatus and another node apparatus by using a lower layer signaling protocol on the basis of said request; and said upper layer signal is edited according to the number of lower layer paths in said node apparatus and in said another node apparatus.   
     
     
         2 . The capacity variable link setting method as claimed in  claim 1 , said traffic data obtaining step including the steps of:
 said node apparatus measuring traffic of the upper layer, and storing measured data in a database as said traffic data; and   reading said traffic data from said database as necessary.   
     
     
         3 . The capacity variable link setting method as claimed in  claim 1 , said increase/decrease determination step including the steps of:
 said node apparatus preparing determination data used for determining increase or decrease of the number of lower layer paths from said traffic data; and   determining the number of lower layer paths to be added or subtracted by comparing said determination data and a predetermined threshold.   
     
     
         4 . The capacity variable link setting method as claimed in  claim 3 , wherein said determination data is an amount of traffic forecast by using variation of traffic with respect to time. 
     
     
         5 . The capacity variable link setting method as claimed in  claim 3 , wherein said determination data is the maximum value of a linear function, within a time range, that is an approximation of variation of time-series traffic data, in which said time range is from a time when determination of increase or decrease of lower layer path is performed to a time when determination of increase or decrease of lower layer path is performed next. 
     
     
         6 . The capacity variable link setting method as claimed in  claim 3 , wherein said predetermined threshold is a function in which the number of lower layer paths is a variable. 
     
     
         7 . The capacity variable link setting method as claimed in  claim 1 , said increase/decrease determination step including the step of:
 determining increase or decrease of a lower layer path by performing negotiation between said node apparatus and said another node apparatus.   
     
     
         8 . The capacity variable link setting method as claimed in  claim 1 , said increase/decrease determination step including the step of:
 determining increase or decrease of a lower layer path in consideration of two determination results, wherein one determination result is a lower layer path increase/decrease determination result sent from said another node apparatus to said node apparatus, and another determination result is a lower layer path increase/decrease determination result in said node apparatus.   
     
     
         9 . The capacity variable link setting method as claimed in  claim 1 , wherein route selection in the increase/decrease step is performed by using OSPF or CSPF. 
     
     
         10 . The capacity variable link setting method as claimed in  claim 1 , wherein said lower layer signaling protocol is RSVP-TE or an expanded protocol of RSVP-TE. 
     
     
         11 . The capacity variable link setting method as claimed in  claim 1 , wherein said lower layer signaling protocol is CR-LDP or an expanded protocol of CR-LDP. 
     
     
         12 . The capacity variable link setting method as claimed in  claim 1 , wherein said lower layer signaling protocol is LDP or an expanded protocol of LDP. 
     
     
         13 . The capacity variable link setting method as claimed in  claim 1 , wherein said request for increasing or decreasing said lower layer path from the upper layer to the lower layer includes information triggering said node apparatus to edit said upper layer signal, so that a signaling message for setting up a lower layer path and a signaling message for editing said upper layer signal are integrated, and increase or decrease of a lower layer path and editing of an upper layer signal are performed by using one signaling. 
     
     
         14 . The capacity variable link setting method as claimed in  claim 1 , wherein, instead of sending said request and using said lower layer signaling between said node apparatus and said another node apparatus, a network operation system that manages said hierarchical network sends a message to each node apparatus in said hierarchical network, so that each node apparatus sets up said lower layer path and edits said upper layer signal. 
     
     
         15 . The capacity variable link setting method as claimed in  claim 1 , wherein the network of the upper layer is one of an IP network, a gigabit Ethernet network, and a fibre channel network. 
     
     
         16 . The capacity variable link setting method as claimed in  claim 1 , wherein the network of the lower layer is an SDH network or an optical transport network.