Optimal sync for rapid spanning tree protocol
US7177946B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 2001 |
| Grant date | Feb 13, 2007 |
| Priority date | — |
| Expiry date | Apr 7, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L45/48
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An optimization to the rapid spanning tree protocol (RSTP) is presented. An intermediate network device configured in accordance with the present invention preferably includes a plurality of ports for receiving and forwarding messages and a spanning tree protocol (STP) engine which is coupled to the ports. If the device receives a bridge protocol data unit (BPDU) message from a designated port of a neighboring intermediate network device and the BPDU represents a proposal by the neighboring device to rapidly transition its port to the forwarding state, the device first determines whether or not it is the root the bridged network. If the device is not the root, and the BPDU message was received on the device's existing root port or on its newly selected root port, the device preferably invokes an “optimal sync” mechanism. Specifically, the device transitions only its alternate root port(s) and the previous root port, if any, to the blocking state, while leaving all of its designated ports, if any, in the forwarding state. The device then returns an agreement BPDU message to the neighboring device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.