Browse Prior Art Database

Outband Signaling Switching System Optimization

IP.com Disclosure Number: IPCOM000081760D
Original Publication Date: 1974-Aug-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 20K

Publishing Venue

IBM

Related People

Aillerie, Y: AUTHOR [+4]

Abstract

In switching systems using the outband signaling technique, a call transmitted through several switching modes SN1, SN2, SN3, from origin terminal 1 to destination terminal 2, assumes a "start to transmit" message to be sent back to origin terminal so that transmission of the data message can occur. When the backward marking technique is used, this "start to transmit" message is passed on the next switching mode when a free path is available, for further transmission of the data message. This path is then marked and remains idle until data are transmitted.

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Outband Signaling Switching System Optimization

In switching systems using the outband signaling technique, a call transmitted through several switching modes SN1, SN2, SN3, from origin terminal 1 to destination terminal 2, assumes a "start to transmit" message to be sent back to origin terminal so that transmission of the data message can occur. When the backward marking technique is used, this "start to transmit" message is passed on the next switching mode when a free path is available, for further transmission of the data message. This path is then marked and remains idle until data are transmitted.

This technique permits the use of a channel between the moment at which it is marked for future transmission and the moment at which it is actually used. For that purpose, information is sent through the network in form of basic framing units (BFU) of 8 bytes. A BFU contains either a signaling message or data.

When a switching mode has not yet received the first data BFU to be transmitted on a path reserved for this transmission, it can use the free slot for the transmission of a signaling message. The signaling message being identified by a flag bit ahead of the BFU can be distinguished from the data coming later on through the same channel.

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