Cisco Express Forwarding

Abstract: Tag switching is a way to combine the label-swapping forwarding paradigm with network-layer routing with particular application to the Internet. This has several advantages. Tags can have a wide spectrum of forwarding granularities, so at one end of the spectrum a tag could be associated with a group of destinations, while at the other end, a tag could be associated with a single application flow. At the same time, forwarding based on tag switching, due to its simplicity, is well suited to high-performance forwarding. These factors facilitate the development of a routing system that is both functionally rich and scalable. Last, tag switching simplifies the integration of routers and asynchronous transfer mode switches by employing common addressing, routing, and management procedures.

Abstract: A packet forwarding method and apparatus performs multiprotocol routing (for IP and IPX protocols) and switching. Incoming data packets are examined and the flow (i.e., source and destination addresses and source and destination socket numbers) with which they are associated is determined. A flow table contains forwarding information that can be applied to the flow. If an entry is not present in the table for the particular flow, the packet is forwarded to the CPU to be processed. The CPU can then update the table with new forwarding information to be applied to all future packets belonging to the same flow. When the forwarding information is already present in the table, packets can thus be forwarded at wire speed. A dedicated ASIC is preferably employed to contain the table, as well as the engine for examining the packets and forwarding them according to the stored information. Decision-making tasks are thus more efficiently partitioned between the switch and the CPU so as to minimize processing overhead.

Abstract: From the Publisher: This invaluable reference provides realistic, practical design solutions from Cisco Systems-the Internetworking authority. Teaches how to construct and support robust ISP connections to the Internet Illustrates Inter- and Intra-domain routing issues, topologies, and scenarios for practical application The only Internetworking book emphasizing domain routing issues and protocols endorsed by Cisco!

Abstract: A communication system comprises a path management server that configures forwarding path information that is configured by arranging link IDs for identifying communication interfaces provided in respective forwarding nodes in a forwarding path of a data transfer network or links extending between said respective forwarding nodes and neighboring nodes thereof. For packets to which is added a header containing the forwarding path information, a forwarding node performs packet forwarding processing in accordance with the forwarding path information.