Browse Prior Art Database

Data Switch Error Isolation and Reporting

IP.com Disclosure Number: IPCOM000036342D
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 3 page(s) / 39K

Publishing Venue

IBM

Related People

Kaiser, JM: AUTHOR [+2]

Abstract

A data switching unit that sets up and controls dynamic connections between pairs of communications ports can also detect errors that occasionally occur on the data links or inside the switching unit. A method of identifying and reporting the location of these errors is disclosed. (Image Omitted)

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Data Switch Error Isolation and Reporting

A data switching unit that sets up and controls dynamic connections between pairs of communications ports can also detect errors that occasionally occur on the data links or inside the switching unit. A method of identifying and reporting the location of these errors is disclosed.

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A data switching unit is pictured in Fig. 1, which contains multiple communications ports (1,2,4,5) which are connected to communications links. These ports can receive data packets on their links which request a dynamic, short term, connection to another port in order to pass data from one link to another. Once the conversation is over, another packet will request that the connection be severed. As in all communications systems, the data is subject to noise that may cause errors in the data stream. In the data coding scheme used by this data switching unit, the valid characters are constrained in both value and sequence such that errors are readily detected by checking circuits. This disclosure describes a method whereby using this checking, it is possible to isolate the errors to either the communication links or the internal paths in the data switch. Such isolation is desirable since a persistent pattern of such errors may indicate the need for maintenance to one of these system components.

Each port adapter (PA) (1 and 5 in Fig.1) contains two error- checking circuits, one on the in-bound portion of the communications link and one on the out-bound portion. Each PA also contains two error counters one for each of the respective error detection circuits and a error flag register which contains a bit to indicate a local error and one to indicate a remote (other PA detected) error. At the start of a communications session, after agreeing to connect together,

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the two Port adapters will reset their error counters and flag registers to zero. During the session, the error-checking circuits monitor their...