D-1
Appendix D
Beacon and
Soft Error Types
and Definitions
This appendix describes the various Media Access Control (MAC)
errors that can occur from a PC workstation on a token ring network.
In the descriptions below, the term “Nearest Active Upstream
Neighbor,” or NAUN, is used. In a token ring network, data flows
only in one direction. NAUN defines the last active station on the
ring to receive the network data and report it to the error-reporting
station. The sequential lobe-to-lobe data flow in Andrew MAUs is
from lobe port one to lobe port 16. Therefore, if the reporting station
is attached to port five, and the station on lobe port four is inactive,
but the port three station is active, the NAUN to lobe port five is lobe
three.
Also, some of the following descriptions recommend that you check
the Token Ring Adapter card for a station. The most convenient
method is to swap the card in the station with a known working one.
Inspecting the cabling of a reporting station involves checking for
broken or cold solder connections at the connectors and broken wires
in the cable.
