Patent ID: 9083602
Filing Date: 2015-07-14
Classification: H04L

Abstract:
1. A communication system comprising; a plurality of communication devices transferring a packet between the plurality of communication devices through a communication path, wherein the plurality of communication devices includes a first communication device and a second communication device, wherein in order to verify connectivity of the communication path, between the first communication device and the second communication device: the first communication device stores, in a first region of header information of the packet, first information for designating the second communication device at which the packet should be looped back, the first communication device further stores, in a second region of the header information of the packet, second information on a loopback point of the second communication device, the first communication device sends the packet, to which the first information and the second information have been added, and the second communication device receives the packet to which the first information and the second information have been added and determines whether the packet should be looped back at the second communication device itself by referring to the first information of the packet, and upon determining that the packet should be looped back at the second communication device itself, the second communication device determines the loopback point of the second communication device by referring to the second information, and then transmits a response packet to the first communication device, wherein the first region is a portion showing a packet Time To Live of a transfer label, and the second region is a portion of a label showing failure-related information.