Patent ID: 7289431
Filing Date: 2007-10-30
Classification: H04L

Abstract:
1. A packet transmission method implemented by a packet transmission system including at least a first label-switched path set on a first line, a second label-switched path set on a second line, and a first recovery path, the method comprising: when there is no fault occurring in the first line and the second line, upon receipt of a first packet, affixing a first label to the first packet and transmitting the first packet with the first label affixed thereto to the first label-switched path; and upon receipt of a second packet, affixing a second label to the second packet and transmitting the second packet with the second label affixed thereto to the second label-switched path, while faults occur in the first line and the second line, upon receipt of the first packet, affixing a third label to the first packet and transmitting the first packet with the third label affixed thereto to the first recovery path; and upon receipt of the second packet, affixing a fourth label to the second packet and transmitting the second packet with the fourth label affixed thereto to the first recovery path, wherein at least one of (1) and (2) is true: (1) the first packet is designated to be passed via the first label-switched path and the second packet is designated to be passed via the second label-switched path due to difference in priority levels, and each of the third label and the fourth label includes one respective priority level of the first packet and the second packet, (2) a first virtual private network (VPN) is set on the first line, and a second VPN is set on the second line, and the first packet is designated to be passed via the first line and the second packet is designated to be passed via the second line, wherein each of the third label and the fourth label includes a recovery label and a working label, the packet transmission system further includes a third label-switched path set on the first line, a fourth label-switched path set on the second line and lower in priority than the third label-switched path, and a second recovery path: while faults occur in the first line and the second line, upon receipt of the first packet received from the first label-switched path, said packet communication system uses a new discovery label to replace the recovery label of the third label in a packet received from the first label-switched path to provide a fifth label before the first packet and transmits the first packet with the fifth label affixed thereto to the second recovery path, upon receipt of the second packet received from the second label-switched path, said packet communication system uses a new discovery label to replace the recovery label of the third label in a packet received from the second label-switched path to provide a sixth label before the second packet and transmits the packet with the sixth label affixed thereto to the second recovery path, and each of the fifth label and the six label includes said one respective priority level of the first packet and the second packet.