Differential forwarding in address-based carrier networks

摘要

The invention relates to enabling differential forwarding in address-based carrier networks such as Ethernet networks. There is described a method of and connection controller for establishing connections (76, 77) in a frame-based communications network comprising nodes (71-75 and 78) such as Ethernet switches. The connections are established by configuring, in various of the nodes, mappings for forwarding data frames, such as Ethernet frames. The mappings are from a combination of a) a destination (or source) address corresponding to a destination (or source) node (73) of the connection and b) an identifier, such as a VLAN tag. The mappings are to selected output ports of the various nodes. By using the combination of destination (or source) address AND identifier, the mappings enable data frames belonging to different connections (76, 77) to be forwarded differentially (ie forwarded on different output ports) at a node (75) despite the different connections having the same destination node. This enables flexibility in routing connections and the ability to perform traffic engineering.

主权项

1. A method of providing a Virtual Private LAN Service (VPLS) across a carrier Ethernet network, the method comprising:
at a first node of the carrier Ethernet network, receiving a frame from a customer, the frame having a first customer MAC address as a customer source MAC address and a second customer MAC address as a customer destination MAC address; identifying the frame to be transported across the carrier Ethernet network by encapsulating it with a VLAN identifier, an encapsulating source MAC address and an encapsulating destination MAC address, the encapsulating source MAC address being a MAC address of the first node; forwarding the encapsulated frame across the carrier Ethernet network based on the combination of the VLAN identifier and the destination MAC address without changing the VLAN identifier; receiving the encapsulated frame at a second node; at the second node, configuring a mapping between the customer source MAC address of the frame and a combination of the MAC address of the first node and the VLAN identifier, the MAC address of the first node being learned from the encapsulating source MAC address of the frame; andforwarding the frame to the customer based on the customer destination MAC address.