Abstract: The invention relates to a technique for protecting a point-to-multipoint primary tree in a connected mode communications network set up from a primary root node to leaf nodes in the event of a fault affecting the primary root node by means of a back-up tree between a back-up root node and at least one merge node, said at least one merge node belonging to a branch of the primary tree coming from the primary root node. A merge node executes the following steps: a step of receiving a request to set up the back-up tree sent by the back-up root node including an identifier of the protected primary root node; and a step of configuring a routing rule in a table, the aim of said rule being to route packets coming from the back-up tree to branches of the primary tree coming from said merge node, said routing rule being activated only in the event of a fault affecting the primary root node.

Abstract: A technique protects, in a communications network, a point-to-multipoint primary tree between a root node and primary leaf nodes of the network if a failure occurs affecting one of the primary leaf nodes. One network node receives from another upstream network node a request to protect the primary tree via a backup branch leading to a backup leaf node situated downstream from said node, if a failure affecting one of the primary leaf nodes to be protected occurs, the backup leaf node being associated with the primary leaf node to be protected. If the node is connected directly to the downstream primary leaf node to be protected, it configures a backup routing rule for routing packets from an upstream primary branch to the downstream backup branch and, possibly, to the downstream primary branch(es) and is activated in the event of a failure affecting the primary leaf node to be protected.

Abstract: A technique protects, in a communications network, a point-to-multipoint primary tree between a root node and primary leaf nodes of the network if a failure occurs affecting one of the primary leaf nodes. One network node receives from another upstream network node a request to protect the primary tree via a backup branch leading to a backup leaf node situated downstream from said node, if a failure affecting one of the primary leaf nodes to be protected occurs, the backup leaf node being associated with the primary leaf node to be protected. If the node is connected directly to the downstream primary leaf node to be protected, it configures a backup routing rule for routing packets from an upstream primary branch to the downstream backup branch and, possibly, to the downstream primary branch(es) and is activated in the event of a failure affecting the primary leaf node to be protected.

Abstract: The invention relates to a technique for protecting a point-to-multipoint primary tree in a connected mode communications network set up from a primary root node to leaf nodes in the event of a fault affecting the primary root node by means of a back-up tree between a back-up root node and at least one merge node, said at least one merge node belonging to a branch of the primary tree coming from the primary root node. A merge node executes the following steps: a step of receiving a request to set up the back-up tree sent by the back-up root node including an identifier of the protected primary root node; and a step of configuring a routing rule in a table, the aim of said rule being to route packets coming from the back-up tree to branches of the primary tree coming from said merge node, said routing rule being activated only in the event of a fault affecting the primary root node.

Abstract: A method is provided for determining a point-to-multipoint tree connecting a root node to a plurality of leaf nodes (some nodes in different domains) used by a path calculation entity associated with a current domain. The method comprises receiving from at least one other path calculation entity associated with a downstream domain at least one message including a first set of identifiers including at least one identifier of a bunch of branches comprising at least one branch and a respective cost associated with said bunch, the bunch comprising at least one branch enabling connection to leaf nodes in downstream domains, and determining at least one new bunch of branches comprising at least one branch as a function of said at least one first set received, said new bunch of branches having a minimum cost and making it possible also to contact the leaf nodes of the current domain.