Service Plane Fast Reroute for Network Failure Detection
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Solution Overview
Problem
Traditional link state protocols in computer networks take a long time to adapt to failures, leading to traffic loss and performance issues in applications like VoIP and multimedia, as they require updating forwarding tables and recalculating paths, which can take up to several seconds.
Innovation Solution
Implementing a monitor component at the service layer to detect failures or degradation of service enabling technology functions, which triggers a fault detection network protocol to reroute traffic through a backup path using Bidirectional Forwarding Detection (BFD) and Fast Reroute mechanisms, allowing for automatic rerouting without operator intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional link state protocols (OSPF/IS-IS) are used to detect and adapt to node/link failures, then the network can maintain routing consistency, but the convergence time is long (500 milliseconds to several seconds) causing traffic loss
Solution Approach 1:
The patent establishes Fast Reroute (FRR) backup paths in advance before failures occur. When a service function fails, the ingress router can immediately switch traffic to the pre-computed backup path without waiting for traditional link-state protocol convergence, thus resolving the contradiction between routing consistency and convergence time
Solution Approach 2:
The patent implements a monitoring mechanism that continuously tracks the operational status of service functions. When a failure is detected, the system provides feedback to trigger Fast Reroute, enabling rapid response to failures without waiting for periodic link-state protocol updates, thereby reducing convergence time while maintaining routing consistency
2Reliability
If Fast Reroute is implemented to reduce convergence time and prevent traffic loss, then service continuity is improved, but the system complexity increases due to additional monitoring components and backup path management
Solution Approach 1:
The patent introduces a dedicated monitoring component as an intermediary between the service function and the Fast Reroute mechanism. This intermediary handles the complexity of service status detection and failure notification, allowing the core Fast Reroute system to remain relatively simple while still achieving improved service continuity
Solution Approach 2:
The monitoring component autonomously detects service function failures and triggers Fast Reroute without requiring manual intervention or complex centralized control. This self-service approach reduces the operational complexity of managing FRR systems while maintaining high service continuity
3Reliability
If service function performance degradation is monitored and Fast Reroute is triggered, then service level agreements are maintained, but false positives may cause unnecessary traffic rerouting and network disruption
Solution Approach 1:
The patent implements threshold-based monitoring that compares service function performance against predefined thresholds before triggering Fast Reroute. This preliminary check prevents false positives by ensuring that only significant performance degradations trigger rerouting, while minor fluctuations are ignored, thus maintaining SLA compliance without causing unnecessary disruptions
Data Source
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AI summary
Techniques are described for detecting failure or degradation of a service enabling technology function independent from an operational state of a service node hosting the service enabling technology function. For example, a service node may provide one or more service enabling technology functions, and service engineered paths may be traffic-engineered through a network to service node network devices that host a service enabling technology function. A monitor component at the service layer of the service node can detect failure or degradation of one or more service enabling technology functions provided by the service node. The monitor component reports detection of failure or degradation to a fault detection network protocol in a forwarding plane of the service node. The fault detection network protocol communicates with an ingress router of a service engineered path to trigger fast reroute by the ingress of traffic flows to bypass the affected service enabling technology function.