Browse Prior Art Database

Terminal to Terminal Data Communications

IP.com Disclosure Number: IPCOM000082860D
Original Publication Date: 1975-Feb-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Brodd, WD: AUTHOR [+2]

Abstract

In a typical centralized data communications system, one station is designated as the control (primary/master) station and all remote stations are designated as terminal (secondary/slave) stations. Operation is such that all transmissions are directed to or from the control station.

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Terminal to Terminal Data Communications

In a typical centralized data communications system, one station is designated as the control (primary/master) station and all remote stations are designated as terminal (secondary/slave) stations. Operation is such that all transmissions are directed to or from the control station.

The control station has system responsibility for managing and/or scheduling the communications facility, and for initiating appropriate error recovery procedures, when required, due to persistent transmission errors or station malfunction. Control of the transmission activity is accomplished by a COMMAND field in the control station transmissions to the terminal stations, and by a RESPONSE field in the terminal transmissions to the control station.

The COMMAND and RESPONSE fields (see drawings) provide data link level functions in forward and reverse directions respectively, e.g. information transfer, acknowledgments, negative acknowledgments, polling, busy, etc. The control station, in general, contains significantly more communications oriented logical capability than a terminal station.

For some applications, it is desirable to permit data transmission between two terminal type stations without a control station in the system. In the case of leased communication facilities, this would require a direct communications facility between the two terminal stations or, in the more general case of switched communications facilities, establishing a...