Distributed BPDU processing for spanning tree protocols
AssigneeForce 10 Networks, Inc.
InventorJagjit Choudhary
Life of this patent
Estimating the term…
Abstract
A distributed spanning tree protocol is implemented on a modular packet switch. At least some port-specific spanning tree functionality, for instance a port receive state machine and/or a port transmit state machine, operates on a processor on a line port module. At least some bridge-specific spanning tree functionality operates on a processor on a management or control module. When the spanning tree is stable, the line port module processor handles routine spanning tree “hello” messages without having to involve the control module processor. This arrangement allows the switch to handle large and/or multiple spanning trees and large numbers of bridged ports without overloading the control module processor with routine spanning tree module communications.
Claims18
A method of operating a packet switch having a control module and at least two line modules each comprising one or more line ports, the method comprising:
- operating a spanning tree protocol master process on the control module, the master process comprised of a first group of spanning tree protocol functions;
- operating a spanning tree protocol slave process on each of the line modules, the slave process on each of the line modules comprised of a second group of spanning tree protocol functions which includes at least one function that is different than the functions comprising the first group, the spanning tree protocol slave process performing at least some Bridge Protocol Data Unit (BPDU) processing for BPDUs associated with the line ports on the line module;
- and
- operating a synchronization process between the control module and each of the line modules to maintain agreement between the first group of spanning tree protocol functions and the respective second group of spanning tree protocol functions.
A packet switch comprising:
- a control module having a control processor operating a spanning tree protocol master process comprised of a first group of spanning tree protocol functions;
- a first line module having a plurality of first line ports and a first line module processor operating a first spanning tree protocol slave process which is comprised of a second group of spanning tree protocol functions at least one function of which is different than the functions comprising the first group, the first spanning tree protocol slave process performing at least some Bridge Protocol Data Unit (BPDU) processing for BPDUs associated with at least one of the first line ports:
- a second line module having a plurality of second line ports and a second line module processor operating a second spanning tree protocol slave process which is comprised of the second group of spanning tree protocol functions at least one function of which is different than the functions comprising the first group, the second spanning tree protocol slave process performing at least some BPDU processing for BPDUs associated with at least one of the second line ports;
- and
- a configuration communication channel for communicating configuration information between at least the control module and the first line module, and the control module and the second line module, the spanning tree protocol master process using the configuration communication channel to maintain synchronization between itself and the first and second spanning tree protocol slave processes.
Dependencies are inferred from the claim text.