Patent ID: 7508774
Filing Date: 2009-03-24
Classification: H04L

Abstract:
1. A method for extending the Spanning Tree Protocol (STP) to provide redundancy and avoid loops in the topology of a service domain associated with a data transport service provided using a provider core network, comprising: defining at each of a plurality of provider edge (PE) devices participating in the service, each participating PE being connected to the other participating PE's by a full mesh of mesh connections through the provider core network, a virtual core port that encompasses all of the ports on the PE that are associated with a mesh connection from the PE to one or more other PE's participating in the service; configuring each participating PE to associate the virtual core port with a virtual core bridge representing the core of the service domain; and ensuring that the virtual core bridge becomes and remains the root bridge for purposes of the spanning tree protocol (STP); wherein the virtual core bridge does not correspond to any one physical switch or bridge in the core of the service domain but instead represents collectively the core of the service domain; wherein for purposes of the spanning tree protocol (STP) each PE considers its virtual core port, which represents all of its mesh connections to PE's participating in the service, to be its root port; and wherein ensuring that the virtual core bridge becomes and remains the root bridge for purposes of the spanning tree protocol (STP) ensures that no physical switch can become the root bridge for purposes of the spanning tree protocol.