Dual ring fault isolation.

摘要

Stations (T) on a faulty token ring which includes a control adapter (16) are removed one at a time starting with the most down stream station from the control adapter or if a station up stream from the last station is known to be good, all of the stations down stream from that station are removed and the one at a time removal starts with the known good station. The control adapter transmits special beacon frames during the station removal process and when the removal of a station results in receipt of the special beacon frame at the control adapter, the control program identifies a fault domain which includes the station whose removal caused the special beacon to be received at the control adapter and the station immediately up stream from that station. The stations in the fault domain are selectively subjected tests and removed from the ring when a failure is detected. <IMAGE>