Multicast LSP Reconstruction via Timer-Based Path Transition
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Solution Overview
Problem
Current multicast communication technologies experience data stream interruptions and packet loss during path adjustments in MPLS networks due to immediate withdrawal of old LSPs before new ones are established, lacking a retransmission mechanism to ensure quality of service.
Innovation Solution
Implement a method where a label switching router (LSR) calculates and sets up a new optimized multicast LSP, sends a mapping request to an upstream node, and uses a timer to delay the withdrawal of the old LSP until data stream confirmation or a set time is reached, ensuring continuous data flow and reducing packet loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the LDP immediately sends a withdraw message to the former upstream node when a route change is detected, then the new optimized multicast LSP can be established quickly, but the data stream forwarding is temporarily interrupted and packets are lost
Solution Approach 1:
The patent applies preliminary action by starting a timer immediately when the mapping request is sent to the new upstream node. This timer creates a time window during which the old LSP is maintained, allowing the new LSP to be established without immediately withdrawing the old path. This preliminary timing mechanism ensures that packet loss is minimized while still enabling quick LSP reconstruction.
Solution Approach 2:
The patent implements beforehand cushioning by maintaining the old LSP active for a predetermined time period through the timer mechanism. This creates a protective buffer that cushions against data stream interruptions during the transition. The old path remains available as a backup until the new path is confirmed operational, preventing harmful packet loss while enabling route optimization.
2Reliability
If the LDP waits for data stream confirmation before sending the withdraw message, then packet loss is reduced, but the LSP reconstruction time increases
Solution Approach 1:
The patent applies periodic action through the timer mechanism that periodically checks whether the new LSP is operational. The timer creates structured time intervals for verification, balancing the need for reliability with the need for timely reconstruction. This periodic verification approach prevents indefinite waiting while ensuring adequate confirmation of the new path's operational status.
Solution Approach 2:
The patent utilizes parameter changes by adjusting the timer's predetermined time period based on network conditions and requirements. This allows the system to flexibly balance between reconstruction speed and reliability by modifying the time parameter. The configurable time parameter enables optimization for different network scenarios, reducing both packet loss and unnecessary delays.
3Productivity
If no timer mechanism is used and the withdraw message is sent immediately, then the LSP adjustment is fast, but the quality of multicast service is seriously influenced due to packet loss
Solution Approach 1:
The patent introduces an intermediary mechanism in the form of a timer that mediates between the need for fast LSP adjustment and the need to prevent packet loss. This intermediary time buffer allows the system to transition from immediate withdrawal (which causes harm) to controlled withdrawal (which maintains quality). The timer acts as a mediator that reconciles the conflicting requirements of efficiency and service quality.
Solution Approach 2:
The patent implements feedback by monitoring whether data streams are successfully received on the new LSP path before withdrawing the old path. This feedback mechanism ensures that the LSP adjustment only completes when the new path is verified operational. The feedback loop prevents premature withdrawal that would cause packet loss, while still enabling efficient reconstruction through the timer-based verification process.
Data Source
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AI summary
A method and system for improving a quality of communication based on a label distribution protocol is provided, and the method includes the following steps. When a local label switching router (LSR) finds out a change of a route at an upstream node in a multicast label switching path (LSP), it calculates and sets up a new optimized multicast LSP according to the label distribution protocol (LDP), and delays to send a withdraw request to the upstream node in the former multicast LSP. Through the embodiments of the disclosure, an interruption of the data stream in the multicast LSP reconstruction procedures can be avoided or reduced, so that the losing of data packets caused by the multicast LSP adjustment is greatly reduced, and the quality of communication of the multicast is improved.