Single-Loop Switch Topology Recovery Without STP Convergence

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Solution Overview

Problem

Existing network protocols like STP and RSTP take significant time to establish and resume network topology, leading to data loss in modern networks.

Innovation Solution

A method for forming and resuming a single loop network using network switches with ports that can be enabled or disabled, utilizing control frames to quickly rebuild and resume network topology without root bridge election or spanning tree protocol data unit exchanges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If STP technology is used to avoid network loops, then network stability is improved, but topology establishment time increases to 30 seconds

Engineering Contradiction:
Improvenetwork stabilityVSAvoidtopology establishment time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent pre-assigns port roles (root port, designated port, blocked port) and states before topology changes occur, eliminating the need for lengthy election processes. When topology changes happen, ports can immediately transition to their predetermined states without waiting for STP convergence, reducing recovery time from 30 seconds to nearly instantaneous.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamic port state transitions that allow ports to rapidly change between blocking and forwarding states based on real-time topology changes. This dynamic approach enables the network to adapt quickly to failures while maintaining loop avoidance, resolving the contradiction between stability and speed.

Inventive Principle:
Principle #15Dynamics

2Speed

If RSTP technology is used to reduce topology establishment time, then convergence speed is improved to 2-3 seconds, but data loss still occurs during the transition period

Engineering Contradiction:
Improveconvergence speedVSAvoiddata loss during transition
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The patent pre-configures port roles and states before topology changes occur, allowing ports to immediately assume their correct forwarding or blocking states when changes happen. This eliminates the 2-3 second convergence period of RSTP and prevents data loss during transitions, as ports are already in their proper states before data traffic needs to resume.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If traditional STP/RSTP protocols are used with root bridge election, then network loop prevention is achieved, but protocol complexity and establishment time increase

Engineering Contradiction:
Improveloop preventionVSAvoidprotocol complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the complex root bridge election process from the topology management mechanism. Instead of requiring bridges to exchange BPDU packets and perform multi-step elections, the patent directly assigns port roles based on predetermined criteria, simplifying the protocol while maintaining loop prevention capabilities through blocked port assignment.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4293966B1Method for resuming topology of single loop network and switch network system
Publication Date: 2026.01.14 REALTEK SEMICON CORP
  • EP4293966B1 patent drawingFigure 1~2
  • EP4293966B1 patent drawingFigure 3
  • EP4293966B1 patent drawingFigure 4

AI summary

A method for resuming topology of a single loop network and a network switch system are provided. The network switch system includes one or more first network switches (10) each having a first port (102) and a second port (102) and a second network switch (10) having a third port (102) and a fourth port (102). When the first port (102) of one of the first network switches (10) is abnormal, a recovery control frame (RF) is transmitted through the second port (102). The second network switch (10) sets the third port (102) in a disabled state to an enabled state. When the abnormal port is resumed, the first network switch (10) transmits a block control frame (BF) through the second port (102). The second network switch (10) sets the third port (102) in the enabled state to the disabled state and transmits a forward control frame (FF) through the fourth port (102). The first network switch (10) sets the first port (102) in the disabled state to the enabled state.