Abstract: The method is for sending information through a topology. A first and second node each having a first node having a first access port, a second access port and a first uplink connected to a first router and a second router, respectively. A third node is provided that has a first access port and a first uplink, the first uplink of the third node being connected to the second access port of the first node. A first packet is sent via the first access port to the second node. The second node adds a first port number to a tag of the first packet and sends the first packet via the first uplink of the second node to the first access port of the first node. The first node receives the first packet via the first access port of the first node. The first node adds the first port number to the tag and adds a first port number of the first access port of the first node to the tag. The first node sends the first packet via the first uplink of the first node to a first router.

Abstract: The tandem node system has a first node having an access link connected to a first port group of a first customer and a first network link connected to a first router. A second node has an access link connected to the first port group of the first customer and a first network link connected to a second router. The first node has a second network link connected to a second network link of the second router.

Abstract: The packet processor system has a port for receiving packets from a first network. A line interface unit is connected to the port for determining the types of packets that are received by the port. A generic pipeline stage assembly is connected to the line interface unit and includes a plurality of generic pipeline stages each having a request engine for sending lookup requests to a lookup engine and a modifier engine for receiving lookup results from the lookup engine. A packet memory is connected to a last generic pipeline stage of the generic pipeline stage assembly and an output line interface unit is connected to the packet memory and a second network.