Patent ID: 6522627
Filing Date: 2003-02-18
Classification: H04L

Abstract:
A method of switching connection oriented services over a connectionless network, the method comprising establishing engineering tunnels in the connectionless network, establishing user tunnels within the engineering tunnels, and transporting said connection oriented services via said user tunnels, wherein management of said connection oriented services is performed by the transmission of signalling information via said engineering tunnels, wherein said tunnels comprise MPLS or L2TP tunnels, and wherein said connection oriented services are provided with an indication of the tunnel protocol containing those services, wherein said network comprises a hierarchy of sub-networks each incorporating a plurality of nodes comprising IP Layer 2 switches, and wherein, within each said sub-network, each node has a first database of topology information relating to that sub-network, and a second database of summary information relating to other sub-networks, said other sub-networks being listed in the second database as logical group nodes, and wherein, to establish an end to end connection between first and second users, a first host node of the first user determines from its first and second databases a logical node containing a second host node of the second user, forwarding in an engineering tunnel via a plurality of intermediate nodes a connection request to that second host node, establishing the connection within a user tunnel contained in the engineering tunnel, and, at each intermediate node, providing a connection admission control so as to guarantee that, for an accepted connection, a predetermined level of service is maintained for that connection.