Hierarchical PCE Cross-Domain Path Computation

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Solution Overview

Problem

In multi-domain MPLS-TE and GMPLS networks, existing methods for computing cross-domain separation paths face challenges, such as low success ratios due to unreasonable node or link selections for working paths, and require prior knowledge of domain sequences between head and tail domains.

Innovation Solution

A hierarchical Path Computation Element (PCE) conceptual model is used, where a parent PCE coordinates sub-PCEs to compute cross-domain separation paths without pre-known domain sequences, by generating candidate separation domain sequences and intra-domain path computation requests, and configuring intra-domain paths to form candidate cross-domain separation paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If sequential path computation is used to compute working path first, then protection path, then the computation process is simple, but the success ratio of acquiring cross-domain separation path decreases when working path node/link selection is unreasonable

Engineering Contradiction:
Improvecomputation process simplicityVSAvoidsuccess ratio of acquiring cross-domain separation path
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent generates multiple candidate domain sequences in advance before performing path computation. This preliminary action allows the system to have multiple potential paths ready, so if one working path selection fails to produce a valid protection path, alternative domain sequences can be tried without restarting the entire computation process, thereby increasing the success ratio while maintaining computational simplicity.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If simultaneous path computation is used to increase success ratio, then the success ratio of acquisition of cross-domain separation path increases, but domain sequence between head domain and tail domain needs to be known in advance

Engineering Contradiction:
Improvesuccess ratio of acquisition of cross-domain separation pathVSAvoidrequirement of pre-known domain sequence
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent dynamically generates and evaluates multiple candidate domain sequences during the computation process rather than requiring a fixed predetermined sequence. The system can adaptively switch between different domain sequences based on path computation results, making the domain sequence flexible rather than static, thus increasing success ratio without requiring advance knowledge of the correct domain sequence.

Inventive Principle:
Principle #15Dynamics

3Reliability

If multiple candidate domain sequences are generated and evaluated, then the success ratio of acquiring cross-domain separation path improves, but the computation time and complexity increase

Engineering Contradiction:
Improvesuccess ratio of acquiring cross-domain separation pathVSAvoidcomputation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent generates multiple candidate domain sequences (excessive action) but evaluates them in a systematic order, allowing partial acceptance of sequences that yield valid paths. The system doesn't need to exhaustively evaluate all possible sequences if a valid cross-domain separation path is found earlier, thus balancing the trade-off between exploring multiple options and limiting computation time.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3163813B1Method for acquiring cross-domain separation paths, path computation element and related storage medium
Publication Date: 2021.01.06 ZTE CORP
  • EP3163813B1 patent drawingFigure 1
  • EP3163813B1 patent drawingFigure 2
  • EP3163813B1 patent drawingFigure 3(a)~3(b)

AI summary

A method for acquiring a cross-domain separation path includes: when a cross-domain separation path computation request is received, acquiring K pairs of candidate separation domain sequences according to a cross-domain network abstraction topology (41); traversing the K pairs of candidate separation domain sequences, generating corresponding intra-domain path computation requests for various domains through which candidate separation domain sequences in the network pass, and transmitting the intra-domain path computation requests of the various domains(42); when at least one pair of intra-domain paths for the intra-domain path computation request are received, configuring each intra-domain path of the at least one pair of intra-domain paths to a corresponding position in the K pairs of candidate separation domain sequences, to form K pairs of candidate cross-domain separation paths (43); and determining one pair of cross-domain separation paths from the K pairs of candidate cross-domain separation paths, and transmitting the cross-domain separation paths as a computation result of the cross-domain separation path computation request (44). There are also disclosed another method for acquiring a cross-domain separation path, a related path computation element, and a related computer storage medium.