Cisco 7000 Series Hardware Installation And Maintenance page 92

Token Ring Network
2-18
Figure
Token Ring and IEEE
802.5
around the network
Possession
transmit
must
wait
to until
When
on
the ring are idle the token
stations
all
the token has no
receiving
have
does information
station that
the token
free to
changes
busy
information the next
this to
the ring reaches
circulates until
it
and
further processing
passes
frame
information continues
frame
checks the returned
to
determines
station
sending
original
and
token information frame and
While
the information
frame
release
which
is enabled
is
wait Therefore
collisions
scheme
allows the user
priority
use the ring more
to
frequently
token with
passing higher
seize the token
stations to
as
by the
station that
generates
and
receives
station
it
as passes
Connections
Physical
are token-passing
networks
of the token grants the
detects token
free
it
passing
packet
information send
to
it
simply
transmit the
to seizes
the information
token
appends
The busy token
the ring
station on
the intended
destination
the token and
information
busy
the ring
to circle
until
it
that
ensure the destination
the receiving
that station
transmits new free token
the ring there
is is
circling
described in
later this
section
Token Ring networks
cannot
occur in
to designate station
any
than stations
lower-priority
own
than
its
designated
priority
The
token
soon
as
possible
and
the token
reservation
token
the
Preparing Network
which
move small
frame
to transmit station
right
by
token
labeled
is
as afree
the token
free to
passes
of the token
token
alters bit
wishes
to transmit
it
with the information
which
the information
station copies
frame back
out
to
reaches the original sending
received the information
station
the information
accepted
out the ring
to
network
no token on the
so other
stations
wishing
which
as high priority
Stations seize or reserve
cannot
which
allows
priority
frame
contains
priority field
which be
can
by
field set
Preparing
Connections
called
token
with information
the
If station
the next station
frame
which
and
then sends
frame
for
The
the ring
which
station
When
the
the
it
purges
early token
unless
transmit
to must
allows the
station
highest-priority
which
is set
higher-priority
2-27
for Installation