Route Compression Algorithm for IP Table Size Reduction

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Solution Overview

Problem

The increasing size of Internet Protocol (IP) route tables necessitates more router memory and processing power, leading to challenges such as TCAM overflow and inefficient data forwarding due to the need for more expensive and power-consuming TCAM chips.

Innovation Solution

A route compression algorithm is applied to IP route tables, where nodes in a routing tree are compressed based on shared gateways, reducing the number of entries in the forwarding table without altering data forwarding behavior, using techniques like radix trees and Patricia trees for efficient lookup.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the number of IP routes in the route table is increased, then the routing capability and coverage are improved, but the TCAM space requirement increases leading to higher cost and power consumption

Engineering Contradiction:

Improverouting capabilityVSAvoidTCAM space

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges multiple route entries into a single compressed entry when they share the same gateway. Specifically, when a node and its children in the routing tree have identical gateway addresses, the algorithm compresses these into a single parent entry, reducing the total number of route entries that need to be stored in TCAM while maintaining the same routing functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The compressed route entry serves multiple functions by representing both the parent node and its children with the same gateway. This universal entry can match multiple destination prefixes simultaneously, allowing a single TCAM entry to perform what would traditionally require multiple separate entries.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If the number of IP routes is increased, then the routing coverage is improved, but the processing power and memory requirements increase

Engineering Contradiction:

Improverouting coverageVSAvoidmemory and processing requirements

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The algorithm combines multiple route entries that point to the same gateway into a single compressed entry in the forwarding table. This merging reduces the number of entries that the data plane must process and store, thereby reducing memory requirements and processing overhead while maintaining complete routing coverage.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If more TCAM chips are added to handle route table overflow, then the forwarding capability is improved, but the cost and power consumption increase significantly

Engineering Contradiction:

Improveforwarding capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

By merging multiple route entries into compressed entries based on shared gateway information, the patent reduces the total number of entries that must be stored in TCAM. This reduction decreases the required TCAM capacity, thereby reducing the number of TCAM chips needed and the associated power consumption and cost.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS7903666B1Method and system for compressing route entries in a route table based on equal-cost multi-paths (ECMPs) matches

Publication Date: 2011.03.08 EXTREME NETWORKS INC

AI summary

A route compression algorithm is applied to route entries of a route table. The route entries are maintained as nodes in a routing tree. The compression algorithm compresses child nodes having a common gateway with their respective parent nodes. The route entries associated with uncompressed nodes are installed into a forwarding table of a routing device that employs longest prefix match (LPM) lookup to forward data packets.