Abstract: Method and system for tracking transient errors and controlling data traffic in a high speed packet switching network node. The traffic exits each node through a transmit queue per connection between end users.
The queue is monitored at both queue level through a threshold based mechanism (53) and a control of time activity mechanism (55). If trouble is detected by any one of these mechanisms, the queue packet admission is momentarily barred. To that end, a Line Resources Manager (LRM) provides queue threshold and time-out references and keeps monitoring the node global buffering memory available. If required, the LRM may also report to Network Management facilities for possible rerouting of the traffic.
March 31, 1997
Date of Patent:
April 24, 2001
Cisco Systems, Incorporated
Pierre Gerardin, Patrick Massi, Victor Spagnol
Abstract: A device for switching packets at high speed. For each packet, the A device matches packet data with protocols, to determine how to switch the packet. Matching of data with protocols is highly parallel; the device simultaneously retrieves a data byte, compares a data byte with a protocol byte, tests a comparison result, and executes a processor instruction. A switching engine having a comparator and a decision tree memory. The comparator includes three outputs for indicating a comparison result (less-than, equal-to, or greater-than). The tree memory includes three corresponding banks of addressable memory. Each memory location comprises an entry for a next location, an entry for a next protocol byte, and an entry for a processor instruction. A set of protocol tests are assembled into the tree memory, and a set of routing tables are dynamically generated into the tree memory.
April 18, 1994
Date of Patent:
April 16, 1996
Cisco Systems Incorporated
Bruce A. Wilford, Bruce Sherry, David Tsiang, Anthony Li
Abstract: A system and protocol are provided for routing data packets from a host on a LAN through a virtual address belonging to a group of routers. The host is configured to point to the virtual address so that the packets it sends out of its LAN are always directed to a virtual router which may be any one of the group of routers. An active router in the group of routers emulates the virtual router. A standby router, also from the group of routers, backs up the active router so that if the active router becomes inoperative, the standby router automatically begins emulating the virtual router. The host router does not know which router from the group is actually handling the data packets it sends. If the standby router becomes inoperative or takes over for the active router, other routers in the group hold an election to determine which of them should take over for the standby router.