Specifications

B.6 Station States
FDDI Overview B–11
B.6 Station States
B.6.1 Definition
The station state is defined by FDDI standards as: the internal configuration of the
paths within the station. Stations can be in one of two states: the Through state or the
Wrap state (see Figure B–5).
For example, DAS or DAC stations that are in an (unwrapped) dual ring are in the
Through state. If a station detects a failure, causing it to wrap the rings together, that
station transitions to the Wrap state.
Figure B–5 Wrapped FDDI Ring
B.6.2 FDDI Naming Convention
When transitioning to the Wrap state, the station can adjust its internal configuration
in a number of ways that are specified by the FDDI standard. The FDDI standard
requires that each station configuration type has a specific naming format, and that
the station is required to use that specific naming format when reporting internal
configuration status to management.
• All Digital SAS and SAC devices report: wrap_S
• All Digital DAS and DAC devices in the wrapped state report: c_wrap_A (con-
catenated wrap A) or c_wrap_B (concatenated wrap B)
Where c_wrap_A indicates: concatenated wrap A.
To explain further, c_wrap_A means that the B port is not active, the station
has wrapped the ring, and the A port is the active port.
DAS
FDDI Station
DAS
FDDI Station
LKG-10099-96F
Wrapped Station
Break in Cable
Wrapped Station
DAS
FDDI Station
DAS
FDDI Station
DAS
FDDI Station
DAS
FDDI Station