Communication device

Abstract

A communication device comprising: a checking unit checking whether a bandwidth from the ingress of first path down to the egress thereof and a bandwidth from the ingress of second path down to the egress thereof as a standby of a partial zone of first path, are established or not; a route information management unit generating, when the checking unit confirms that the bandwidth from the ingress of first path down to the egress thereof and the bandwidth from the ingress of second path down to the egress thereof as the standby of the partial zone of first path are established, route maintaining information for maintaining the bandwidth of the partial zone of first path; and a transmission unit transmitting the route maintaining information generated by the route information management unit to the neighboring communication device on the side of the egress of first path.

1 . A communication device, in a communication network including: a first communication path, along which a plurality of communication devices is cascade-connected, having an ingress and an egress; and a second communication path, along which the plurality of communication devices is cascade-connected, the communication devices existing both ends thereof being different from each other on the first communication path, having its ingress corresponding to the communication device, of the communication devices at both ends, located on the side of the ingress of the first communication path and its egress corresponding to the communication device, of the communication devices at both ends, located on the side of the egress of the first communication path, the communication device being the communication device located at the ingress of the second communication path, comprising:
 a checking unit checking whether a bandwidth from the ingress of the first communication path down to the egress thereof and a bandwidth from the ingress of the second communication path down to the egress thereof as a standby of a partial zone of the first communication path, are established or not;   a route information management unit generating, when the checking unit confirms that the bandwidth from the ingress of the first communication path down to the egress thereof and the bandwidth from the ingress of the second communication path down to the egress thereof as the standby of the partial zone of the first communication path are established, route maintaining information for maintaining the bandwidth of the partial zone of the first communication path; and   a transmission unit transmitting the route maintaining information generated by the route information management unit to the neighboring communication device on the side of the egress of the first communication path.   
   
   
       2 . A communication device according to  claim 1 , further comprising a reception unit receiving, from the neighboring communication device on the side of the egress of the first communication path, route error information showing occurrence of a link fault on the egress side from the neighboring communication device on the side of the egress of the first communication path,
 wherein when the checking unit confirms that the bandwidth from the ingress of the first communication path down to the egress thereof and the bandwidth from the ingress of the second communication path down to the egress thereof as the standby of the partial zone of the first communication path are established and when the reception unit receives, from the neighboring communication device on the side of the egress of the first communication path, the route error information showing the occurrence of the link fault on the egress side from the neighboring communication device on the side of the egress of the first communication path, the transmission unit transmits the route maintaining information to the neighboring communication device on the side of the egress of the first communication path.   
   
   
       3 . A communication device, in a communication network including: a first communication path, along which a plurality of communication devices is cascade-connected, having an ingress and an egress; and a second communication path, along which the plurality of communication devices is cascade-connected, the communication devices existing both ends thereof being different from each other on the first communication path, having its ingress corresponding to the communication device, of the communication devices at both ends, located on the side of the ingress of the first communication path and its egress corresponding to the communication device, of the communication devices at both ends, located on the side of the egress of the first communication path, the communication device being the communication device located on the first communication path between the ingress and the egress of the second communication path, comprising:
 a reception unit receiving route maintaining information for maintaining a bandwidth in a partial zone of the first communication path from the neighboring communication device on the side of the ingress of the first communication path;   a route information management unit stored with the route maintaining information; and   a transmission unit transmitting the route maintaining information to the neighboring communication device on the side of the egress of the first communication path.   
   
   
       4 . A communication device according to  claim 3 , wherein if the link fault occurs between the self communication device and the neighboring communication device on the side of the ingress of the first communication path, the transmission unit transmits the route maintaining information stored in the route information management unit to the neighboring communication device on the side of the egress of the first communication path. 
   
   
       5 . A communication device according to  claim 3 , wherein when the reception unit receives delete request information for deleting the bandwidth of the first communication path from the neighboring communication device on the side of the egress of the first communication path, the route information management unit deletes the route maintaining information. 
   
   
       6 . A communication device according to  claim 3 , wherein if the link fault occurs between the self communication device and the neighboring communication device on the side of the egress of the first communication path, the transmission unit transmits route error information showing the occurrence of the link fault on the side of the egress of the first communication path to the neighboring communication device on the side of the ingress of the first communication path. 
   
   
       7 . A communication device, in a communication network including: a first communication path, along which a plurality of communication devices is cascade-connected, having an ingress and an egress; and a second communication path, along which the plurality of communication devices is cascade-connected, the communication devices existing both ends thereof being different from each other on the first communication path, having its ingress corresponding to the communication device, of the communication devices at both ends, located on the side of the ingress of the first communication path and its egress corresponding to the communication device, of the communication devices at both ends, located on the side of the egress of the first communication path, the communication device being the communication device located at the egress of the second communication path, comprising:
 a reception unit receiving route maintaining information for maintaining a bandwidth in a partial zone of the first communication path from the neighboring communication device on the side of the ingress of the first communication path; and a route information management unit stored with the route maintaining information.   
   
   
       8 . A communication device according to  claim 7 , further comprising a transmission unit transmitting, if the link fault occurs on the first communication path between the ingress and the egress of the second communication path, when the route information management unit is stored with the route maintaining information, and when the reception unit receives delete request information for deleting a resource of the first communication path from the communication device on the second communication path, the delete request information to the neighboring communication device on the side of the ingress of the first communication path. 
   
   
       9 . A network system including a first communication path having an ingress and an egress, and a second communication path, of which a branch point and a merge point, as viewed from the first communication path, are specified as an ingress and an egress, generated so as to bypass a middle zone of the first communication path that is specified from the branch point to the merge point, data to be sent, if any fault does not occur in the middle zone, from the ingress of the first communication path being forwarded to the egress of the first communication path via the middle zone, the system comprising:
 a detection unit detecting the fault in the middle zone;   a switch control unit switching over, when the fault in the middle zone is detected, a part of a forwarding route of the data from the ingress down to the egress of the first communication path to the second communication path from the middle zone, and switching back, if recovered from the fault in the middle zone, the part of the forwarding route of the data from the ingress down to the egress of the first communication path to the middle zone from the second communication path; and   an inhibiting unit inhibiting, during a period from the occurrence of the fault in the middle zone up to the recovery, a release of a resource for the first communication path with respect to a fault-not-yet-occurring area of the middle zone.   
   
   
       10 . A communication device in a network system including a first communication path having an ingress and an egress, and a second communication path, of which a branch point and a merge point, as viewed from the first communication path, are specified as an ingress and an egress, generated so as to bypass a middle zone of the first communication path that is specified from the branch point to the merge point, data to be sent from the ingress of the first communication path being forwarded to the egress of the first communication path via the middle zone if any fault does not occur in the middle zone, a forwarding route of the data sent from the ingress of the first communication path being switched over to the second communication path from the middle zone if the fault occurs in the middle zone, and the forwarding route of the data sent from the ingress of the first communication path being switched over to the middle zone from the second communication path if the middle zone is recovered from the fault, the communication device disposed in the middle zone, comprising:
 a reservation unit reserving a resource for the first communication path that is related to the middle zone when generating the first communication path; and   a reservation updating unit updating a reserved status of the resource for the first communication path,   wherein the reserved status of the resource for the first communication path is not canceled due to the occurrence of the fault in the middle zone, and   the reservation updating unit updates the reserved status even when the fault occurs in the middle zone.