US 5,982,747 AGranted

Method for managing failures on dynamic synchronous transfer mode dual ring topologies

AssigneeDynarc Inc.

InventorsLars H.ang.kan Ramfelt, Lars Markus Hidell

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Abstract

The dynamic synchronous transfer mode dual ring topology has two rings with opposite fiber directions. The dual rings may have a plurality of common nodes. A first channel may be established in a first segment extending between a first and second nodes. Tokens associated with the first channel may be provided. In this way, time slots may be transmitted in the first channel from the first node to the second node. If a fiber failure occurs in the first segment, the second node is likely to first detect the fiber failure and transmit a fiber failure message. It is then determined if the first channel extends across the fiber failure. If the first channel is affected by the fiber failure then a channel failure message is transmitted and the first channel is terminated and all the tokens associated with the first segment are removed. If the first channel is not affected then time slots are continued to be transmitted on the first channel.

Claims20

Dependent claims

A method of managing a failure on a dynamic synchronous transfer mode dual ring topology, comprising the steps of;

providing a first dynamic synchronous transfer mode ring topology having a first node, a second node and a third node, the first ring topology using time division multiplexing having a capacity that is divided into time cycles that are dividable into time slots, the first topology being adapted to transmit frames only in a first fiber direction;
providing a second dynamic synchronous transfer mode ring topology having the first node and the second node in common with the first ring topology, the second ring topology being adapted to transmit frames only in a second fiber direction that is opposite the first fiber direction;
establishing a first channel in a first segment on the second ring topology extending between the first and second node, the second node being downstream of the first node;
providing tokens associated with the first channel;
transmitting information in the time slots forming the first channel;
the second node detecting a fiber failure in the first segment on the second ring topology;
the second node transmitting a fiber failure message;
determining if the first channel extends across the fiber failure;
if the first channel extends across the fiber failure, transmitting a channel failure message, terminating the first channel and removing all tokens associated with the first segment;
and
if the first channel does not extend across the fiber failure, continuing transmitting information in the time slots forming the first channel on the second ring topology.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/067,350Filed 27 Apr 1998 · continuation in part
Priority: SE 950467928 Dec 1995
Granted: 9 Nov 1999
Term ends: Not estimatedThe source records don’t support an estimate.

Classification19 codes

H04L 12/2852
Characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]: metropolitan area networks
H04J 3/085
Intermediate station arrangements, e.g. for branching, for tapping-off: for ring networks, e.g. SDH/SONET rings, self-healing rings, meashed…
H04L 12/422
Loop networks: synchronisation for ring networks
H04L 12/437
Loop networks: ring fault isolation or reconfiguration