摘要:
A method system for interfacing a client system in a first network domain with a Provider Link State Bridging (PLSB) network domain. At least two Backbone Edge Bridges (BEBs) of the PLSB domain 20 are provided. Each BEB is an end-point of a connection in the first network domain to the client system and an end-point of at least a unicast path defined within the PLSB domain 20. An inter-node trunk is provided in the PLSB domain 20 for interconnecting the at least two BEBs. A phantom node is defined in the PLSB domain 20. The phantom node has a unique address in the PLSB domain 20 and is notionally located on the inter-node trunk one hop from each of the BEBs. Each of the BEBs is configured such that: an ingress packet received from the client system via the connection in the first network domain is forwarded through a path notionally rooted at the phantom node; and an egress subscriber packet destined for the client system is forwarded to the client system through the connection in the first network domain.
摘要:
A system for interfacing a client system in a first network domain with a Provider Link State Bridging (PLSB) domain includes at least two Backbone Edge Bridges (BEBs) of the PLSB domain. Each BEB is an end-point of a connection in the first network domain to the client system and an end-point of at least a unicast path in the PLSB domain. An inter-node trunk is provided in the PLSB domain for interconnecting the BEBs. A phantom node is defined in the PLSB domain and is notionally located on the inter-node trunk. Each of the BEBs is configured such that: an ingress packet received from the client system via the connection in the first network domain is forwarded through a path notionally rooted at the phantom node; and an egress packet destined for the client system is forwarded to the client system through the connection in the first network domain.
摘要:
A method of multicast route computation in a link state protocol controlled network. A spanning tree is computed from a first node to every other node in the network using a known spanning tree protocol. The network is then divided into two or more partitions, each partition encompassing an immediate neighbour node of the first node and any nodes of the network subtending the neighbour node on the spanning tree. Two or more of the partitions are merged when a predetermined criterion is satisfied. Nodes within all of the partitions except a largest one of the partitions are then identified, and each identified node examined to identify node pairs for which a respective shortest path traverses the first node.
摘要:
A method ensures that multicast packets follow the same loop-free path followed by unicast packets in a packet communication network. The communication network includes at least one first area interconnected through at least one area border node (“ABN”) to a second area. Each ABN has a first level port connected to each first area and a second level port connected to the second area. Each multicast packet forwarded includes a header having a root-id identifying a root of a multicast tree. A data packet is received at an ABN. Responsive to receiving a multicast packet at a second level port of an area border node, the root-id of the multicast packet is examined and if the multicast packet is to be forwarded over at least one of the first level ports, a different root-id is substituted into the packet before the packet is forwarded over the first level port.
摘要:
A method ensures that multicast packets follow the same loop-free path followed by unicast packets in a packet communication network. The communication network includes at least one first area interconnected through at least one area border node (“ABN”) to a second area. Each ABN has a first level port connected to each first area and a second level port connected to the second area. Each multicast packet forwarded includes a header having a root-id identifying a root of a multicast tree. A data packet is received at an ABN. Responsive to receiving a multicast packet at a second level port of an area border node, the root-id of the multicast packet is examined and if the multicast packet is to be forwarded over at least one of the first level ports, a different root-id is substituted into the packet before the packet is forwarded over the first level port.
摘要:
A consistent tie-breaking decision between equal-cost shortest (lowest cost) paths is achieved by comparing an ordered set of node identifiers for each of a plurality of end-to-end paths. Alternatively, the same results can be achieved, on-the-fly, as a shortest path tree is constructed, by making a selection of an equal-cost path using the node identifiers of the diverging branches of the tree. Both variants allow a consistent selection to be made of equal-cost paths, regardless of where in the network the shortest paths are calculated. This ensures that traffic flow between any two nodes, in both the forward and reverse directions, will always follow the same path through the network.