Preparing
Network
Connections
FDDI
Physical
Connections
Fiber
Distributed
Data
Interface
FDDI
which
specifies
iOO-Mbps
token-passing
dual-ring
network
using
fiber-optic
transmission
media
is
defined
by
the
ANSI
X3
standard
and by
ISO
9314
the international
version
of the
ANSI
standard
An FDDI
network
comprises
two
token-passing
fiber-optic
rings
primary
ring
and
secondary
ring
An
FDDI
ring consists
of
two
or
more
point-to-point
connections
between
adjacent
stations
An FDDI
ring consists
of
two
or
more
point-to-point
connections
between
adjacent
stations
On
most networks
the
primary
ring
is
used
for data
communication
and
the
secondary
ring
is
used
as
backup
Class
or single-attach
stations
SAS
attach
to
one
ring
and
are
typically
attached
through
concentrator
Class
or dual-attach
stations
DAS
attach
to
both
rings
Figure
2-24
shows
typical
FDDI
configuration
with
both
DASs
and
SASs
Figure
2-24
Typical
FDDI
Configuration
with
DAS
Concentrator
and
SAS
SASs
Class
typically
attach
to
the primary
ring through
concentrator
which
provides
connections
for multiple
SASs
The
concentrator
ensures
that
failure
or
power
down
of
any
SAS
does
not
interrupt
the ring
SASs
use
one
transmit
port
and one
receive
port
to
attach
to
the
single
ring
DASs
Class
have
two
physical
ports
designated
PHY
and
PHY
each
of
which
connects
the
station
to
both
the primary
and
secondary
rings
Each
port
is
receiver
for
one
ring
and
transmitter for the other
For example
PHY
receives
traffic
from
the primary
ring and
PHY
transmits
to
the primary
ring
2-36
Cisco
7513
Hardware
Installation
and
Maintenance
Summary of Contents for 7513 Series
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Page 121: ...Site Log 2 56 Cisco 7513 Hardware Installation and Maintenance ...
Page 162: ...Troubleshooting the Processor Subsystem 4 10 Cisco 7513 Hardware Installation and Maintenance ...
Page 266: ...Interface Processor LEDs B 16 Cisco 7513 Hardware Installation and Maintenance ...
Page 270: ...C 4 Cisco 7513 Hardware Installation and Maintenance ...
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