Automatic Redundant Path Establishment in Packet Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current network protocols, such as IS-IS and OSPF, primarily provide shortest paths and constrained shortest paths, but lack the ability to efficiently establish and manage explicit paths in packet networks, especially in Ethernet networks, where configuring each node for explicit paths is difficult and existing solutions like RSVP-TE have high implementation burdens.
Innovation Solution
Implementing a method using a link state routing protocol and a local computation engine to establish and restore redundant paths by receiving explicit path TLVs, calculating primary and backup paths using shortest path algorithms, and updating network graphs to prune or bias links, allowing for flexible path control and reservation in packet networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional path control protocols (spanning tree, IS-IS, OSPF) are used, then network provides default shortest path or spanning tree paths, but the ability to establish explicit paths is limited or requires high implementation burden
Solution Approach 1:
The network devices automatically compute and establish explicit paths using the explicit path TLV carried in link state advertisements. Each device independently calculates the explicit path based on the TLV information and installs forwarding entries without requiring manual configuration or complex protocol extensions, enabling self-service path establishment
Solution Approach 2:
The explicit path TLV acts as an intermediary data structure that carries path identification information through the link state routing protocol. This TLV enables path control functionality by serving as a mediator between the control plane and data plane, allowing explicit path establishment without direct protocol modifications to forwarding logic
2Reliability
If redundant paths are established for network resilience, then network reliability improves, but path management complexity increases
Solution Approach 1:
The system pre-computes and establishes backup paths alongside primary paths using the same link state routing mechanism. When a failure occurs, the backup path is already prepared and can be activated immediately, providing proactive redundancy management without increasing operational complexity during normal operation
Solution Approach 2:
The link state routing protocol is extended to handle both primary and backup path establishment using the same explicit path TLV mechanism. This universal approach allows a single protocol framework to manage multiple path types, simplifying path management by unifying the control mechanism rather than requiring separate protocols for different path functions
3Manufacturing precision
If explicit paths are configured manually on each node, then path control precision improves, but configuration difficulty and time increase
Solution Approach 1:
Network devices automatically receive explicit path information through link state advertisements containing the explicit path TLV and independently compute the precise path routes. This self-service mechanism eliminates manual configuration requirements while maintaining precise path control, as each device autonomously installs the correct forwarding entries based on the TLV data
Data Source
AI summary
A method is implemented by a network device executing a local computation engine and a link state routing protocol. The local computation engine and the link state protocol support automatic establishment of redundant paths and cautious restoration in a packet network. The method includes receiving an explicit path (EP) type length value (TLV) via a link state routing protocol, executing a shortest path algorithm to obtain a shortest path for loose hops of a path identified by the EP TLV, the shortest path to be a primary path, updating a network graph to prune links of the primary path or bias links of the primary path, and calculating a backup path using the shortest path algorithm on the updated network graph.