Local network, particularly Ethernet network having redundancy properties, and redundancy manager for such a network

Abstract

The invention relates to a local network, particularly an Ethernet network having redundancy properties, in which coupling devices (K1, K2, K3) and a redundancy manager (RM) are interconnected in a ring-shaped topology. The redundancy manager opens the ring to create a linear topology if test messages (T11, T12) emitted by said redundancy manager (RM) are received at the other port (P42, P41) within a given period of time, otherwise the redundancy manager (RM) closes the connection. As a so-called redundancy manager observer, at least one of the coupling devices (K3) is configured such that it evaluates messages received at the port (P32) thereof, said port (P32) being connected to the redundancy manager, opens the ring to create a linear topology, and signals an error if more than initial test messages (T11) have been received at said port (P32) and if the status ring opened has been indicated by the redundancy manager (RM) in the last-received initial test message (T11), whereby messages are prevented from circulating on the ring.

Description

technical field [0001] The invention relates to a redundant local area network (in particular Ethernet) according to the general concept of claim 1 and a coupling device for such a network according to the general concept of claim 6 . Background technique [0002] A local Ethernet network with redundancy is disclosed in WO 99 / 46908. In the network described therein, coupling devices and redundancy managers are implemented as Layer-2 components (Layer-2-Komponenten) each with at least two ports, which are each connected to each other via the connection of two ports of adjacent devices. form a ring topology. Herein, "2-layer component" means that at least layers 1 and 2 of the ISO-OSI-7-layer model are implemented in the device. The device thus performs address calculation and telegram forwarding (Telegrammweglenkung). In normal operation, ie no faults occur in the network, the ring is separated by the redundancy manager. This means that telegrams received by the redundanc...

AI Technical Summary

Problems solved by technology

This can cause Telegram to go around in circles in the ring

In the worst case, the bandwidth of the network available for data traffic is occupied such that useful data traffic can no longer be transmitted between users connected on the network

Therefore, the network is not available or only available on a small scale to connected users when this error occurs

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