Communication system, control device, communication method, and program

Abstract

A communication system includes a plurality of forwarding nodes for which is set a processing rule(s) for forwarding a received packet in accordance with a route set in advance, with a processing rule being selected based on a path identifier included in the received packet, to perform packet forwarding; and a control device that sets the processing rule beforehand in the forwarding node in the route, and causes a forwarding node positioned at a start point of the route to add a path identifier in accordance with the route to a received packet and causes a forwarding node positioned at an end point of the route to delete the path identifier from a received packet, on a predetermined occasion.

1 . A communication system, comprising:
 a plurality of forwarding nodes for which is set a processing rule(s) for forwarding a received packet in accordance with a route set in advance, with a processing rule being selected based on a path identifier included in said received packet, to perform packet forwarding; and   a control device that sets said processing rule beforehand in said forwarding node(s) in said route, and causes a forwarding node positioned at a start point of said route to add a path identifier in accordance with said route to a received packet and causes a forwarding node positioned at an end point of said route to delete said path identifier from a received packet, on a predetermined occasion.   
     
     
         2 . The communication system according to  claim 1 , wherein a control device causes the forwarding nodes positioned at a start point and an end point of said route to execute the addition and deletion of a path identifier in accordance with said route, at an occasion when a new flow detection notification is received from said forwarding node. 
     
     
         3 . The communication system according to  claim 1 , wherein said control device comprises:
 a route information storage unit that manages a plurality of routes formed by said forwarding nodes and path identifiers associated with said routes respectively;   a route information management unit that selects an appropriate route from said route information storage unit, when a new flow is generated; and   an action computation unit that sets a processing rule in advance, in a forwarding node in a route selected from said route information storage unit, and also sets a processing rule respectively executing addition and deletion of the path identifier in accordance with said route, in forwarding nodes positioned at a start point and an end point of said selected route.   
     
     
         4 . The communication system according to  claim 1 , wherein said control device performs re-computation of a route between arbitrary forwarding nodes and sets a processing rule corresponding to said route, each time a change of topology of a network formed by said forwarding nodes is detected. 
     
     
         5 . The communication system according to  claim 4 , wherein said communication system gives the same path identifier to routes having an overlapping section, with the same end point forwarding node, among routes between said arbitrary forwarding nodes. 
     
     
         6 . A control device, connected to a plurality of forwarding nodes for which is set a processing rule that forwards a received packet in accordance with a route set in advance, with a processing rule being selected based on a path identifier included in said received packet, to perform packet forwarding;
 said control device comprising:   a first unit setting said processing rule beforehand in said forwarding nodes in said route; and   a second unit causing a forwarding node positioned at a start point of said route to add a path identifier in accordance with said route to a received packet and causing a forwarding node positioned at an end point of said route to delete said path identifier from a received packet, on a predetermined occasion.   
     
     
         7 . The control device according to  claim 6 , wherein said control device causes the forwarding nodes positioned at a start point and an end point of said route to execute addition and deletion of the path identifier in accordance with said route, at an occasion when a new flow detection notification is received from said forwarding node. 
     
     
         8 . The control device according to  claim 6 , further comprising:
 a route information storage unit that manages plurality of routes formed by said forwarding nodes and path identifiers associated with said routes respectively;   a route information management unit that selects an appropriate route from said route information storage unit, when a new flow is generated; and   an action computation unit that sets a processing rule in advance, in a forwarding node in a route selected from said route information storage unit, and also sets a processing rule respectively executing addition and deletion of the path identifier in accordance with said route, in forwarding nodes positioned at a start point and an end point of said selected route.   
     
     
         9 . The control device according to  claim 6 , wherein said control device performs re-computation of a route between arbitrary forwarding nodes and sets a processing rule corresponding to said route, each time a change of topology of a network formed by said forwarding nodes is detected. 
     
     
         10 . A communication method, comprising:
 when a new flow is generated, adding, by a forwarding node positioned at a start point of a route that has been computed in advance a path identifier to a received packet, based on an instruction from a control device, and then forwarding to a subsequent hop; selecting, by a forwarding node that is in a route computed in advance a processing rule based on said path identifier included in a received packet, from among processing rules set in advance by said control device, and forwarding the received packet; and   restoring, by said forwarding node positioned at an end point of said route said received packet to a state before said path identifier was added, based on an instruction from said control device, and then forwarding to a subsequent hop.   
     
     
         11 . The communication system according to  claim 2 , wherein said device comprises:
 a route information storage unit that manages a plurality of routes formed by said forwarding nodes and path identifiers associated with said routes respectively;   a route information management unit that selects an appropriate route from said route information storage unit, when a new flow is generated; and   an action computation unit that sets a processing rule in advance, in a forwarding node in a route selected from said route information storage unit, and also sets a processing rule respectively executing addition and deletion of the path identifier in accordance with said route, in forwarding nodes positioned at a start point and an end point of said selected route.   
     
     
         12 . The communication system according to  claim 2 , wherein said control device performs re-computation of a route between arbitrary forwarding nodes and sets a processing rule corresponding to said route, each time a change of topology of a network formed by said forwarding nodes is detected. 
     
     
         13 . The communication system according to  claim 12 , wherein said communication system gives the same path identifier to routes having an overlapping section, with the same end point forwarding node, among routes between said arbitrary forwarding nodes. 
     
     
         14 . The communication system according to  claim 3 , wherein said control device performs re-computation of a route between arbitrary forwarding nodes and sets a processing rule corresponding to said route, each time a change of topology of a network formed by said forwarding nodes is detected. 
     
     
         15 . The communication system according to  claim 14 , wherein said communication system gives the same path identifier to routes having an overlapping section, with the same end point forwarding node, among routes between said arbitrary forwarding nodes. 
     
     
         16 . The control device according to  claim 7 , further comprising:
 a route information storage unit that manages plurality of routes formed by said forwarding nodes and path identifiers associated with said routes respectively;   a route information management unit that selects an appropriate route from said route information storage unit, when a new flow is generated; and   an action computation unit that sets a processing rule in advance, in a forwarding node in a route selected from said route information storage unit, and also sets a processing rule respectively executing addition and deletion of the path identifier in accordance with said route, in forwarding nodes positioned at a start point and an end point of said selected route.   
     
     
         17 . The control device according to  claim 7 , wherein said control device performs re-computation of a route between arbitrary forwarding nodes and sets a processing rule corresponding to said route, each time a change of topology of a network formed by said forwarding nodes is detected. 
     
     
         18 . The control device according to  claim 8 , wherein said control device performs re-computation of a route between arbitrary forwarding nodes and sets a processing rule corresponding to said route, each time a change of topology of a network formed by said forwarding nodes is detected. 
     
     
         19 . A non-transient computer-readable storage medium storing a program executed in a control device connected to a plurality of forwarding nodes for which is set a processing rule that forwards a received packet in accordance with a route set in advance, with a processing rule being selected based on a path identifier included in the received packet, and packet forwarding being performed; wherein the program executes a process of setting the processing rule beforehand in the forwarding node in the route, and a process, at a predetermined occasion, of respectively executing addition and deletion of the path identifier in accordance with the route, in forwarding nodes positioned at a start point and an end point of the route.