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Techniques for Enhancing the Performance of a Ring-Type Local Communication Network

IP.com Disclosure Number: IPCOM000046489D
Original Publication Date: 1983-Jul-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Andrews, DW: AUTHOR [+4]

Abstract

This article describes several techniques which enhance the operation and performance of a ring-type communication network. One technique describes a procedure for detecting and isolating that part of the ring which causes errors. The other technique describes a procedure for selectively routing data on a ring.

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Techniques for Enhancing the Performance of a Ring-Type Local Communication Network

This article describes several techniques which enhance the operation and performance of a ring-type communication network. One technique describes a procedure for detecting and isolating that part of the ring which causes errors. The other technique describes a procedure for selectively routing data on a ring.

Fig. 1 shows a schematic for a local ring communication network system. A plurality of stations A, B, C and D are coupled thereto. Each station is fitted with a ring interface adapter. The ring adapter checks the CRC in all the frames and may also detect "spurious" violations in the bit encodings. If an error is detected, the ring adapter sets to "1" a bit in the end delimiter (originally, the originator of the frame sets the bit to "0"). Fig. 2 is an example of the delimiter format. If the bit was "0" when the adapter changed it, then the error occurred between that adapter and the previous "upstream" adapter. With reference to Fig. 1, if A originated the frame, B would not see an error which is introduced at the marked error point. However, C, D and A would see the error. C would change the bit from "0" to "1". D and A would set "1" to "1" and would not record a change.

The ring adapter which changes the bit from "0" to "1" increments a counter (not shown). Every time the counter overflows a message is transmitted to a central management facility (not shown), and an indic...