LSP Recovery via Upstream Node State Maintenance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for processing node restarts in GMPLS networks fail to reliably recover Label Switched Paths (LSPs) when multiple consecutive nodes suffer communication failures, leading to service interruptions and instability in the transmission plane.
Innovation Solution
A method using Resource Reservation Protocol-Traffic Engineering (RSVP-TE) where a normal node closest to the restarted node performs self-refresh of control state information during a recovery waiting time, maintaining and recovering control state information if communication is restored within that time, and deleting it if not, to ensure reliable LSP recovery and quick resource release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing RSVP-TE methods are used for node restart processing, then single node recovery is supported, but multiple consecutive node failures cannot be reliably recovered
Solution Approach 1:
The patent applies preliminary action by having the restarted node proactively send a recovery notification message to upstream normal nodes before actual state recovery occurs. This allows upstream nodes to prepare for potential recovery scenarios and maintain control state information during the recovery waiting time, enabling reliable multi-node failure recovery rather than waiting for passive timeout mechanisms.
Solution Approach 2:
The patent implements feedback by establishing a notification mechanism where restarted nodes actively inform upstream nodes of their recovery status. The upstream nodes receive feedback through recovery notification messages and adjust their behavior accordingly - maintaining control state during recovery waiting time if recovery is anticipated, or deleting it if recovery fails within the timeout period. This feedback loop enables adaptive response to multi-node failure scenarios.
2Reliability
If control state information is maintained during recovery waiting time, then LSP recovery reliability improves, but network resource utilization decreases
Solution Approach 1:
The patent applies dynamics by making the control state information maintenance duration flexible rather than fixed. Upstream nodes maintain control state information dynamically during a recovery waiting time period, adjusting the maintenance duration based on whether the restarted node successfully recovers within the timeout. If recovery succeeds, resources are retained; if it fails, resources are released. This dynamic approach optimizes both reliability and resource utilization compared to static timeout-based mechanisms.
Solution Approach 2:
The patent changes the parameter of control state information lifecycle from fixed timeout-based deletion to conditional deletion based on recovery outcome. The recovery waiting time parameter allows the system to transition between two states: maintaining control state information during the waiting period (prioritizing reliability) and deleting it if recovery fails (prioritizing resource utilization). This parameter change enables the system to adapt to different recovery scenarios optimally.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A method, a system and a device for processing failure is provided; the method is applicable to a label switched path (LSP) including a first node, a second node, and at least one third node. The first node and the second node are adjacent nodes suffering communication breakdown. The first node restarts. The third node is a normal node closest to the restarted first node. When the communication between the first node and the second node is broken, the third node maintains control state information of the LSP in certain time. When the communication between the first node and the second node is recovered in the certain time, the first node, the second node, and the third node recover the control state information of the LSP. A failure processing system and a device on LSP are further provided. Therefore, when several nodes on the LSP suffer communication failures, the LSP can be reliably recovered.