SNAX/HLS Configuration and Control Manual

Step 3. Planning Session BINDs
Planning the SNAX/HLS Environment
104705 Tandem Computers Incorporated 2–13
In the BIND message, this attribute is indicated in byte 7, bit 3. In HLSRDT, this
attribute is specified by the BIND attribute CONTENTION-WINNER, where:
SECONDARY corresponds to 0 in the BIND message and PRIMARY corresponds to 1
in the BIND message.
Alternate Code Processing Indicator
This field is not interpreted by SNAX/HLS.
In the BIND message, this attribute is indicated in byte 7, bits 4 and 5. In HLSRDT,
this attribute is specified by the BIND attribute ALT-CODE-ID, where: ASCII-7
corresponds to 0 in the BIND message and ASCII-8 corresponds to 1 in the BIND
message.
Half-Duplex Flip-Flop Reset States
This field is used only under HDUX-FF send/receive mode with brackets. It
determines whether the primary or secondary partner is the first to send after a reset.
Set the field to 0 if the secondary partner sends first, and to 1 if the primary partner
sends first.
In the BIND message, this attribute is indicated in byte 7, bit 7. In HLSRDT, this
attribute is specified by the BIND attribute HDX-FF-RESET-SENDER, where:
SECONDARY corresponds to 0 in the BIND message and PRIMARY corresponds to 1
in the BIND message.
TS Usage The following fields select global configuration values for the transmission control
component of the SNAX/HLS session. Attributes selected in these fields determine
the maximum size of a message segment and the use of session-level pacing.
Pacing Window Sizes
The fields discussed below control the use of pacing. Pacing is a mechanism whereby
the receiver of traffic can prevent the partner from sending more traffic than the
receiver is capable of handling until the receiver explicitly signals willingness to
receive more traffic. In the case where SNAX/HLS is the receiver, the signal is
withheld if there are too many messages queued to the application program.
Session-level pacing is transparent to the SNAX/HLS application except in its impact
on throughput and SNAX/HLS memory requirements.
The SEC-SEND-PACING-SIZE field (BIND message byte 8) controls the pacing
window size for SLU-to-PLU traffic. If single-stage pacing is indicated (the normal
case), both the PLU and SLU use this value to control the pacing. If two-stage pacing
is indicated, the PLU pacing values are indicated by the PRI-RECV-PACING-SIZE
field (BIND message byte 13).
The SEC-RECV-PACING-SIZE field (BIND message byte 9) controls the pacing
window size for the PLU-to-SLU traffic. If single-stage pacing is indicated (the normal
case), both the PLU and SLU use this value to control pacing. If two-stage pacing is
indicated, the PLU pacing values are indicated by the PRI-SEND-PACING-SIZE field
(BIND message byte 12).