APN Configuration and Management Manual

Configuring for Token-Ring Support

SNAX/XF and SNAX/APN Configuration and Management Manual—425836-006

9-7

Token Control of the Ring

The description given previously covers the simplest case of token control. There are

other considerations—timing, priority setting, and early release.



There are a number of sets of timers used to monitor a station’s performance on

the ring. Timing parameters may be set to define polling of the remote station,

retransmission of data frames, acknowledgments, and frame priorities. Timers

used by the HP implementation are covered in the discussion of attributes for the

remote PU object later in this section.



Access control to the token, and thus the right to transmit, can be regulated by

setting priorities within the token. A station can use a token with a setting equal to

or less than that station’s allowed access priority. The token also contains a field

for stations with a high-access priority to request that a subsequent token be

issued only at that higher priority—in effect, a reservation system. All controllers on

Figure 9-5. Token Control of the Ring

Step 1

Step 2

Step 3

Step 4

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