High availability spanning tree with rapid reconfiguration
US6262977A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 1998 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Aug 28, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L45/48
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An improvement to the spanning tree protocol provides for identifying a port on the bridge in the alternate port role which qualifies as a next best root port. Upon detection of a failure at the root port, or other event causing a change in the root port to a blocking state, the next best root port transitions to the root port role, and forwarding state immediately without traversing the listening and learning states of the standard protocol. Also, in networks in which there is a possibility of shared media links between bridges, ports that have the alternate port role, and connect to a LAN which is also connected through a designated port on the same bridge are identified as a backup. The algorithm prevents such backup ports from transitioning to the forwarding state before the designated port connected to the same LAN segment transitions to a blocking state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.