Patent ID: 7502376
Filing Date: 2009-03-10
Classification: H04L

Abstract:
1. A method to provide a loop-free telecommunication network wherein end-user stations (U 1 ; U 2 ) are interconnected through at least one Virtual Private LAN Service VPLS-network (VPLS 1 ; VPLS 2 ) and Layer-2 networks (L2N 1 ; L2N 2 ), the Layer-2 networks including bridges (K; L), said VPLS-network comprising nodes (A, B, C; P, Q, R) with external node ports (pA said bridges comprising external bridge ports (pK each port being associated to a predetermined weight factor, the method comprising the step of using a predetermined protocol to prevent loops through the interconnected nodes and bridges, said method further comprises the steps of: grouping the internal node ports (pA setting the weight factors associated to the port arrangements to the value zero, defining one of the nodes or bridges as a root bridge, calculating, for each of said external node ports (pA selecting the node of which an external node port has the lowest sum of weight factors as primary node for the VPLS-network, and cutting, towards external ports of said root bridge, the coupling of external node ports that have a sum of weight factors that is higher than the sum of weight factors of the external ports of said primary node towards said root bridge.