Browse Prior Art Database

Quick Wrapping and Unwrapping of Network Trunks

IP.com Disclosure Number: IPCOM000123640D
Original Publication Date: 1999-Feb-01
Included in the Prior Art Database: 2005-Apr-05
Document File: 3 page(s) / 99K

Publishing Venue

IBM

Related People

Lindeborg, C: AUTHOR [+3]

Abstract

Described is a method for managing network fault (such as a break in the wiring) between hubs identified as Ring Out and Ring In.

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Quick Wrapping and Unwrapping of Network Trunks

   Described is a method for managing network fault (such
as a break in the wiring) between hubs identified as Ring Out and
Ring In.

   The method used to quick wrap both trunk connections when
signal loss is detected can be broken down into a five step process
described in Figure 1.

   Step 1 shows a healthy connection involving two trunks
(denoted Ring Out and Ring In) where data is being passed along the
primary path from Ring Out to Ring In.  Ring Out is considered to be
"upstream" of Ring In.

   Step 2 occurs when there is a break in the cable between
the trunks.  In this example, the break is on the primary path,
though the same algorithm works equally well for the backup path.
The cable break prevents Ring In from seeing a Token Ring signal, and
this error condition is passed to the central processor (CPU), not
shown.

   In step 3, the CPU performs a quick wrap on the Ring In
trunk segment.  This isolates all stations downstream of this trunk
from the fault.

   After wrapping the Ring In trunk, the CPU proceeds to step
4.  In this step, Ring In's transmitter (on the backup path) is
turned off for a period of one second.  This will cause the Ring Out
trunk, upstream of the fault, to detect a loss of signal.

   This loss signal leads to step 5, where the Ring Out
trunk is quick wrapped.  Wrapping Ring Out isolates all stations
upstream of the trunk from the offending fault, completing all the
necessary...