Patent ID: 9391874
Filing Date: 2016-07-12
CPC Classification: H04L

Claim Text:
1. A method of re-routing traffic in a communications network operating in a hierarchical tree structure where the network traffic is sent from an ingress node to a plurality of egress nodes, wherein the ingress node is a root node of the tree structure and the egress nodes are leaf nodes of the tree structure, and wherein in the event of a fault on a path across the network, the method comprising: determining, by a first node located between the fault and the ingress node, whether the first node is capable of autonomously switching traffic to an alternative sub-tree; as a consequence of the first node determining that the first node is unable to switch traffic to an alternative sub-tree, sending, by the first node, a fault notification signal upstream to a second node located upstream of the first node, wherein the second node is not the ingress node; as a consequence of the first node determining that the first node is able to switch traffic to an alternative sub-tree, determining whether the first node is capable of switching traffic from an initial sub-tree to an alternative sub-tree which avoids the fault; and as a consequence of the first node is determining that the first node is not capable of switching traffic to an alternative sub-tree which avoids the fault, sending, by the first node, a fault notification signal upstream to the second node, and autonomously determining whether the second node is capable of switching traffic to an alternative sub-tree which avoids the fault, wherein the communications network is configured to provide an E-tree service to at least part of the nodes of the communications network, wherein the ingress node is a node responsible for distribution of the E-tree service within the communications network and the egress nodes are nodes attached to destinations of the E-tree service.