Abstract: A method for determining required routes through an Ether based network associated with VLANs by determining a set of spanning trees. The set of spanning trees is determined to provide a number of routes for consideration. Each spanning tree comprising a plurality of links, sorts the VLANs into an order based on one or more VLAN criteria for the network topology, and maps the sorted VLANs onto the set of spanning trees in an order to optimise one or more characteristics relating to the combination of spanning tree and VLAN to determine an optimised VLAN tree mapping for each set of spanning trees for each route. A best primary tree for each route is selected. Possible failures for each link in the best primary tree for each route are analyzed to derive for a backup tree optimised to determine one or more best backup trees in the event of a possible failure.

Abstract: A method for determining required routes through an Ether based network associated with VLANs by determining a set of spanning trees. The set of spanning trees is determined to provide a number of routes for consideration. Each spanning tree comprising a plurality of links, sorts the VLANs into an order based on one or more VLAN criteria for the network topology, and maps the sorted VLANs onto the set of spanning trees in an order to optimise one or more characteristics relating to the combination of spanning tree and VLAN to determine an optimised VLAN tree mapping for each set of spanning trees for each route. A best primary tree for each route is selected. Possible failures for each link in the best primary tree for each route are analyzed to derive for a backup tree optimised to determine one or more best backup trees in the event of a possible failure.

Abstract: A method of operating a node of a telecommunications system, the node comprising a plurality of entities each arranged to send and receive IP packets to peer entities, via a Network Address Translation function, using a layer 4 control protocol which facilitates multi-homing by allowing an entity to include more than one IP address in a layer 4 packet chunk. The method comprises maintaining at each of said plurality of entities a table mapping one or more private addresses of the entity to one or more public addresses of the Network Address Translation function, and, for each association initiation message generated by an entity, including in said layer 4 packet chunk of the message the public IP address(es) of the Network Address Translation function obtained from said table for the corresponding private IP address(es).