Spanning tree with fast link-failure convergence
US6219739A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 7, 2000 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | Sep 7, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/4625
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The Spanning Tree Protocol converges to a new configuration after the loss of a link. A new frame, known as a root link query request BPDU is transmitted to the root bridge in the spanning tree when a bridge detects an indirect link failure through the reception of an inferior BPDU on a blocked port. Each bridge forwards this root link query until the root link query reaches the last reachable upstream bridge or a bridge which has a different Tx_Root_Id than the one identified in the RLQ-REQ-BPDU. If the last reachable bridge is the root bridge identified in the RLQ-REQ-BPDU, then a second new frame known as an RLQ-ACK-BPDU is sent, and the bridge port receiving this acknowledgment BPDU is changed from a blocked port to a designated port. If the RLQ-REQ-BPDU reaches a bridge with a different Tx_Root_Id than the one in RLQ-REQ-BPDU, a third new frame known as RLQ-NAK-BPDU is sent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.