CONNECTIVITY CHECKING OF A BIDIRECTIONAL CIRCULAR PATH IN A COMMUNICATION NETWORK

摘要

It is disclosed a method for checking connectivity of a bidirectional circular path provided in a communication network comprising a number of nodes connected according to a ring topology. The bidirectional circular path comprises two counter-rotating unidirectional circular paths. The nodes are provided with topology information relating to the communication network. One of the nodes generates a connectivity check packet comprising a TTL field, sets its value based on the topology information, transmits the connectivity check packet along one of the two counter-rotating paths and receives it at the opposite side from the same path. In response to the connectivity check packet, the node generates a connectivity check response packet comprising a TTL field, sets its value based on the topology information and transmits the connectivity check response packet along the other counter-rotating path.

主权项

1. A method for checking connectivity of a bidirectional circular path provided in a communication network comprising a number N of nodes connected according to a ring topology, said bidirectional circular path comprising a first unidirectional circular path and a second counter-rotating unidirectional circular path, at least one node of said number N of nodes being provided with topology information relating to said communication network, said method comprising, at said node:
a) generating a connectivity check packet comprising a first time to live field and setting said first time to live field based on said topology information; b) transmitting said connectivity check packet from a first side of said node along said first unidirectional circular path; c) receiving said connectivity check packet at a second side of said node opposite to said first side of said node, from said first unidirectional circular path; d) in response to said connectivity check packet, generating a connectivity check response packet comprising a second time to live field and setting said second time to live field based on said topology information; and e) transmitting said connectivity check response packet from said second opposite side of said node along said second counter-rotating unidirectional circular path.