Cisco 7000 Series Hardware Installation And Maintenance page 98

switches avoid
Optical bypass
normal
an
operation optical bypass
When
station
uninterrupted
onto the ring before reaches
it
shows
2-23
Figure an optical bypass
the of the figure Station
on
left
The
switch
transparent
essentially
However
Station fails the
if
2-23
the of Figure
right
2-23
Bypass
Figure Optical
Station
Station
The
switch reroutes
bypass
and back
sends out the ring
to
it
back
without
on
itself
wrapping
when
back
out
to
it
sending
allow the signal
to
pass
just
downstream
the next
neighbor
Another
for
fault
technique
the designated
concentrators
Only
does the backup
primary
fail
by
segmentation eliminating
switch allows the
light
with switch
bypass
fails
the so the ring does
failed
station
switch Station
installed at
is normally
functioning
allows the
to
signals
switch enables
bypass
optical
DAS
Operation on
the by
signal intercepting
light
This allows the
signal
However
stations that
the ring switches
Optical bypass
them
Therefore
through
significant
on the ring
station far
is
tolerance dual
homing
is whereby
concentrator
primary
passive concentrator activated
is
Preparing
from
the ring
failed stations
to
signal through
directly
pass
the bypass switch reroutes
have wrap back on
not
to
normal
In the
configuration
so the optical bypass switch
without
it
pass through interruption
the
bypassed
configuration
Station
before reaches the
failed
it it
maintain
to
its
existing path
repeat the signal
are operating
normally
do
not repeat or drive
loss
can occur
signal
away
are attached
critical devices
or
active unless
is its link
it
sustains the ring
and
automatically
Preparing
Network Connections
During
itself
back
the signal
itself
shown
appears
shown on
station
switch
bypass
Optical
bypassed
configuration
Station
and
direction
the signal
they
when
the
two
to
lithe
fails
2-33
for Installation