USING THE INFORMATION SCREENS
5-14
5.3.1 Ring Map Screen Data
The FDDI Ring Map shows the address and sequence of each FDDI
device attached to the ring. When first displayed, the station at the
upper left corner of the ring is this station (FDMMIM). The screen
displays node class, node address, and twisted and/or wrapped
conditions (T for twisted and/or W for wrapped) in parentheses. The
following lists the node class possibilities:
NAS
(Null Attached Station) Isolated
station; station not connected to an
FDDI ring.
DAS
(Dual Attached Station) Station that
does not support M ports, but
connects directly to an FDDI primary
and secondary ring using A and B
ports.
DAC
(Dual Attached Concentrator) Station
that supports M ports and connects
directly to an FDDI primary and
secondary ring using A and B ports.
SAS
(Single Attached Station) Station that
accesses the main ring through a
concentrator, creating a ring of trees
topology.
SAC
(Single Attached Concentrator)
Station that accesses the main ring
through another concentrator and, in
turn, allows the connection of more
devices. SACs provide the same
connections as DACs, without
attaching to the dual ring.
While LM updates the map, for example, during a ring topology
change, the screen shows
??-??-??-??-??-??
to illustrate an
undetermined address. You cannot use the scroll commands until
LM finishes rebuilding the map.
Note: The Ring Map display stops at the first occurrence of an
undetermined address, and does not display any known information
beyond this point.