Patent ID: 7606240
Filing Date: 2009-10-20
Classification: H04L

Abstract:
1. A method for preventing a loop in a virtual network, comprising: detecting a failure to transmit data in a first of two or more shared segments, the first shared segment shared by a first and a second physical network ring implemented on the virtual network; determining whether a second of the two or more shared segments transmits data, the second shared segment shared by the first physical network ring and a third physical network ring implemented on the virtual network, the virtual network comprising a plurality of domains wherein each physical network ring is protected by a corresponding automatic protection switching system; changing, by a processor, to a state of blocking data traffic, all but one of a number of ports of a node directly coupled to the first shared segment in response to detecting the failure in the first shared segment and determining the second shared segment does transmit data, wherein each of the number of ports couple the node to a non-shared segment of the first or second physical ring; and designating one node from all nodes directly coupled to either of the first and second shared segments as a root blocker node in response to detecting the failure to transmit data in the first shared segment and determining the second shared segment also fails to transmit data, the root blocker node having one or more non-shared segments directly coupled thereto, and changing, to a state of blocking data traffic, all but one of a number of root blocker ports, wherein each of the number of root blocker ports couple the root blocker node to a non-shared segment of the first or third physical ring.