PCEP Session Establishment via Dynamic TCP Role Assignment

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Solution Overview

Problem

In multi-PCE collaborative computation scenarios, existing PCEP protocols face challenges in establishing sessions while adhering to constraints that limit each pair of communicating ends to a single PCEP session and a single TCP connection, which complicates path computation in complex MPLS/GMPLS networks and impacts hardware performance.

Innovation Solution

A method and device for establishing PCEP sessions among PCEs, where attributes are dynamically or statically configured as TCP servers or clients, ensuring compliance with the constraints by allocating roles based on IP addresses, autonomous domain identifiers, or other parameters to manage TCP connections effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a PCE serves as both TCP server and TCP client in multi-PCE collaboration, then collaborative computation capability is improved, but compliance with protocol constraints (single PCEP session and single TCP connection per pair) deteriorates

Engineering Contradiction:
Improvecollaborative computation capabilityVSAvoidprotocol constraint compliance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements dynamic role assignment where PCEs transition between server and client roles based on session state. When a PCEP session is established, the system dynamically determines which PCE acts as server and which as client, allowing flexible adaptation while maintaining protocol constraints. This is achieved through state tracking mechanisms that monitor session establishment and enforce role differentiation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces a session state management mechanism that acts as an intermediary between the dual server-client capability and protocol constraints. This intermediary tracks which PCE should serve as server or client in each session, mediating the conflict between wanting both PCEs to have full capabilities and needing to enforce single-session constraints.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If PCEs establish multiple TCP connections for collaborative computation, then communication flexibility is improved, but TCP connection management complexity increases

Engineering Contradiction:
Improvecommunication flexibilityVSAvoidconnection management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the communication relationship into distinct sessions, where each session represents a separate logical connection even if using the same physical TCP connection. This segmentation allows multiple collaborative computations to occur through structured session management, providing flexibility without requiring multiple simultaneous TCP connections between the same pair of PCEs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent makes the single TCP connection universal by allowing it to support multiple PCEP sessions sequentially. The same physical connection can be used for different collaborative computation tasks by establishing, managing, and tearing down sessions as needed, reducing the need for multiple permanent connections while maintaining communication flexibility.

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

Data Source

PatentEP2824886B1Path computation element communication protocol session establishment method and device
Publication Date: 2020.05.20 ZTE CORP
  • EP2824886B1 patent drawingFigure 1~2
  • EP2824886B1 patent drawingFigure 3
  • EP2824886B1 patent drawingFigure 4

AI summary

Disclosed are a path computation element communication protocol (PCEP) session establishment method and device. The technical solution comprises: at a PCC or PCE node device side, before needing to establish a PCEP session, allocating a TCP connection communication end attribute to a PCC or a PCE at either end in the manner of static configuration/dynamic designation or election mechanism automatic allocation; or detecting whether to establish a TCP connection relationship, if not, actively connecting the opposite end, and if a plurality of TCP connection relationships has been established, simultaneously cutting off a plurality of connections at both ends, and reinitiating a TCP connection after waiting a random time respectively. The present invention achieves the establishment of a PCEP session in the multi-PCE cooperation computation scenario under the condition of meeting two constraint conditions which are specified by a protocol.