Network Path Performance Identification via Diagnostic Probe Aggregation

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Solution Overview

Problem

Conventional IP routing mechanisms in MPLS networks are unable to determine an optimal path through the core network from ingress PE to egress PE routers, making it difficult to perform routing decisions for QoS-based traffic and ensuring delivery speed/bandwidth guarantees, and customers lack real-time information on path characteristics like delay and jitter.

Innovation Solution

A system and method that aggregates performance characteristics of core network paths to identify an optimal path by parsing messages with attributes such as transport time, delay, and jitter, allowing routers to make informed routing decisions based on real-time performance data, using diagnostic probe messages and Link State Attribute/Label Switched Path messages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional IP routing mechanisms are used in MPLS networks, then basic routing functionality is maintained, but the ability to determine optimal paths and ensure QoS guarantees is lost

Engineering Contradiction:
ImproveQoS guaranteeVSAvoidrouting decision capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces a path computation element (PCE) as an intermediary component that computes optimal paths through the MPLS core network. The PCE receives routing requests, calculates performance characteristics of available paths using gathered network state information, and returns recommended paths to the routing entity. This intermediary resolves the contradiction by providing sophisticated path optimization capabilities without requiring the core routers themselves to perform complex routing decisions, thus maintaining operational simplicity while achieving reliable QoS guarantees.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If real-time path performance monitoring is implemented, then optimal path identification is enabled, but system complexity and measurement requirements increase

Engineering Contradiction:
Improvepath performance dataVSAvoidmonitoring system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a universal path computation element that serves multiple functions: gathering network state information, computing optimal paths, monitoring performance characteristics, and providing routing recommendations. By consolidating these diverse functions into a single multi-functional entity, the system achieves precise real-time path performance monitoring without proportionally increasing overall system complexity. The PCE acts as a central brain that handles all measurement and computation tasks, preventing distributed complexity from proliferating across the network infrastructure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If path computation based on performance characteristics is performed, then optimal routing is achieved, but information processing and computation requirements increase

Engineering Contradiction:
Improverouting efficiencyVSAvoidcomputation resource
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements preliminary gathering and preprocessing of network state information and performance characteristics before actual routing decisions are required. The path computation element maintains an up-to-date database of network conditions, link states, and performance metrics in advance. When routing requests arrive, the PCE can quickly compute optimal paths using pre-gathered information rather than performing exhaustive real-time analysis. This preliminary action significantly reduces the computational burden and energy consumption during actual routing operations while maintaining high routing efficiency.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP1861963B1System and methods for identifying network path performance
Publication Date: 2011.06.01 CISCO TECHNOLOGY INC
  • EP1861963B1 patent drawingFigure 1
  • EP1861963B1 patent drawingFigure 2
  • EP1861963B1 patent drawingFigure 3

AI summary

A system and method for aggregating performance characteristics for core network paths allows computation of message traffic performance over each of the available candidate paths through the core for identifying an optimal core network path. Particular network traffic, or messages, include attributes indicative of performance, such as transport time, delay, jitter, and drop percentage, over individual hops along the candidate path. A diagnostic processor parses these messages to identify the attributes corresponding to performance, and analyzes the resulting parsed routing information to compute an expected performance, such as available bandwidth (e.g. transport rate) over the path. Messages including such attributes may include link state attribute (LSA) messages, diagnostic probe messages specifically targeted to enumerate such attributes, or other network suitable network traffic. In a particular configuration, the messages may be Path Verification Protocol (PVP) messages.