Cisco 7513 Hardware Installation And Maintenance Manual page 102

FDDI Management
Fault
The
dual rings in an
fails such
single contiguous
continue
to
includes
that
Figure
Ring wrap
Note
The
stream
its
upstream
Figure
Station
Station
Station
second
would
example
because
segmentation
FDDI
network
Station in Figure 2-25
as
This removes
ring
In Figure 2-25
operation
and
Stations
only
DAS
2-25 Station Failure
Each
station in refers to
ring
based on
the signal flow
is
neighbor and
transmits
shows
2-25 the primary signal flow
PHY
and from
on Station
the of Station
is upstream
neighbor
could
failure
cause the ring
the ring
into two
segment
separate
Station in Figure
if
2-25
no communication
for
path
tolerance
fault
If station
provide
the ring automatically wraps doubles back
the from
failed station the
the ring
eliminate
to
wraps
and
Ring Recovery Example
Station
Failed
Station
stations
its upstream
neighbor as
on the primary
ring station
the primary downstream
to
signal its
from
transmitted
being
PHY
on
Station Using
to
and
Station the
is
from
in both directions
to
wrap
communicate
could not
rings that
Station fails Stations
fails after
them
between
exists
Subsequent
Network
Preparing
down
on
dual ring shuts
on
itself to
but allows the other
ring stations
and
Station forms smaller
Station
station
downstream
or neighbors
receives the primary
signal
neighbor For example
PHY PHY
on
Station
to
Station
reference
as
downstream
of
neighbor
which
the point of failure
with each For
other
and be
each
will isolated
failures cause additional
for Installation
Preparing
Connections
or
form
ring
from
on
2-37