Daisy-Chained Network Device State Restoration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Ethernet networks face challenges in handling loops, leading to delayed communication and network instability due to the time required for loop detection and topology reconfiguration, which is critical in media networks that require redundancy and daisy-chained solutions.

Innovation Solution

A method for running a computer network with devices arranged in a daisy-chained loop, where each device has at least three ports and stores state information persistently, allowing for a soft reboot that maintains logical port states by validating the copy state and restoring them if valid, thereby avoiding the need to re-run the spanning tree algorithm and ensuring network stability during device reboots.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If standard spanning tree protocol is used to detect and isolate loops in Ethernet networks, then loop detection capability is improved, but network communication stability deteriorates due to isolation delays and topology reconfiguration time

Engineering Contradiction:
Improveloop detection capabilityVSAvoidnetwork communication stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by pre-configuring the network in a daisy-chained loop topology with all ports in forwarding state before operation begins. This eliminates the need for spanning tree protocol to block ports, thereby avoiding communication interruptions while maintaining loop detection capability through alternative mechanisms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts the loop isolation function from the standard spanning tree protocol operation. By removing the port blocking mechanism and using alternative loop management approaches (such as loop prevention at higher layers or selective packet dropping), the network maintains full connectivity without the stability issues caused by port isolation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If devices in daisy-chained loop maintain persistent port states during soft reboot, then network availability is improved, but risk of state inconsistency worsens without proper validation

Engineering Contradiction:
Improvenetwork availabilityVSAvoidstate consistency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by validating the copy state before restoring it during soft reboot. The validation process checks whether the saved port states are consistent with current network conditions before applying them, preventing state inconsistency while maintaining high availability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by maintaining a persistent copy of port states in non-volatile memory during soft reboot. This copy is validated and restored to ensure consistency, allowing the device to quickly resume operation without full re-initialization while maintaining reliability through validation checks.

Inventive Principle:
Principle #26Copying

3Measurement precision

If spanning tree algorithm is re-run after device reboot, then correct topology detection is improved, but network downtime increases

Engineering Contradiction:
Improvetopology detection accuracyVSAvoidnetwork downtime
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by saving port states before reboot and restoring them after reboot. This preliminary preparation eliminates the need to re-run the spanning tree algorithm, reducing network downtime while maintaining topology detection accuracy through state validation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent ensures continuity of useful action by maintaining port states across reboots. The network continues to operate with the same topology configuration without interruption from algorithm re-execution, achieving both fast recovery and accurate topology maintenance through persistent state storage and validation.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP3251303B1Method for running a computer network and computer network
Publication Date: 2021.03.10 ROBERT BOSCH GMBH
  • EP3251303B1 patent drawingFigure 1
  • EP3251303B1 patent drawingFigure 2

AI summary

In a method for running a computer network (2) comprising a number of devices (4a-d) being arranged in a daisy-chained loop and running a spanning-tree algorithm (10) involving handling of state machines (14), wherein each device (4a-d) comprises a bridge (6a-d) having at least three ports (8a-c), whereby during running the network (2) each device (4a-d) can take different states (D, L, F, O) to avoid a loop in the network (2), whereby logical port states (D, L, F, O) of the ports are defined by the state machines (14), for at least one device (4a-d) at least once before a reboot of the device (4a-d) a momentary state (S) of a state machine (14) is stored, and in case of rebooting the state (D, L, F, O, S) of the device (4a-d) is restored, if it is successfully validated that the stored state (S) is still valid. A Computer network (2), comprising a number of devices (4a-d) being arranged in a daisy-chained loop is adapted for performing the method above.