Lightweight Not-via IP Fast Reroute Reducing Address Overhead
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional IP routing protocols experience slow rerouting times, leading to data loss and session disruptions, especially in real-time traffic, and existing IPFRR methods like Not-via addresses face challenges with scalability and computational complexity, particularly when multiple failures occur.
Innovation Solution
The system determines a pair of redundant trees for each node as a root, allowing packets to be forwarded via an IP-in-IP tunnel along the primary or secondary tree in case of link failures, reducing the need for numerous IP addresses and computational complexity, while ensuring packets reach the destination without forming loops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional routing protocols (OSPF or IS-IS) are used for fault recovery, then routing information is propagated and routing tables are re-computed, but rerouting time takes numerous seconds or longer leading to data loss
Solution Approach 1:
The patent pre-computes Not-via addresses and alternate paths before failures occur. Each node maintains pre-calculated backup paths to all other nodes, stored as Not-via addresses. When a failure occurs, packets are immediately redirected using these pre-computed addresses without waiting for routing protocol convergence, thus eliminating rerouting delay while ensuring fault recovery.
Solution Approach 2:
The patent introduces Not-via addresses as intermediary routing targets. Instead of directly recomputing paths between source and destination, the source node redirects packets to a Not-via address that represents an intermediate destination known to provide an alternate path. This intermediary mechanism enables fast rerouting by bypassing the need for full routing table recomputation.
2Speed
If Not-via addresses are used for IPFRR, then fast rerouting is achieved, but numerous IP addresses are required scaling quadratically increasing address management complexity
Solution Approach 1:
The patent makes Not-via addresses universal by enabling each node to serve as a Not-via address for multiple other nodes. Instead of requiring dedicated Not-via addresses for each node pair, any node can function as an alternate path endpoint for multiple sources. This multi-functionality reduces the total number of Not-via addresses from quadratic O(n²) to linear O(n) scaling, as each node maintains Not-via addresses for all other nodes rather than each pair requiring unique addresses.
3Adaptability or versatility
If multiple Not-via addresses are computed for each destination, then alternate paths are available, but computational complexity increases due to numerous shortest path computations
Solution Approach 1:
The patent performs all necessary shortest path computations in advance during normal operation. Each node pre-computes Not-via addresses to all other nodes and stores these results. This preliminary computation eliminates the need for real-time calculations during failures, transforming complex runtime computations into simple lookup operations that redirect packets using pre-stored Not-via addresses.
Data Source
AI summary
A system, method, and node for implementing lightweight Not-via Internet Protocol fast reroutes of a packet in a telecommunications network between a first node and a destination node. The method determines a shortest path between the first node and the destination node and two redundant trees between the first node and the destination node. Each redundant tree provides an alternate path from the first node and the destination node. When a failure in a link between the first node and the destination node is detected, the packet is forwarded to the destination node via a first redundant tree, and if not available, via a second redundant tree. If the second redundant tree is not available, the packet is dropped. If no failure in the link between the first node and the destination node is detected, the packet is sent via the determined shortest path to the destination node.