Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
_______________________________________________________________________________<br />
ACKprior ON|OFF<br />
Default: OFF<br />
Mode: Packet<br />
Host: AN<br />
_________________________________ Parameters: _________________________________<br />
ON - Priority Acknowledgment is enabled.<br />
OFF - This feature is disabled.<br />
_______________________________________________________________________________<br />
This command implements the Priority Acknowledge scheme described by Eric<br />
Gustafson (N7CL), which proposes to improve multiple access packet performance<br />
on HF and VHF simplex channels with hidden terminals. When a busy channel<br />
clears, the acknowledgments are sent immediately, while data and poll bits are<br />
held off long enough to prevent collisions with the ACKs. By giving priority to<br />
data ACKs, fewer ACKs will collide with other station's data, reducing retries.<br />
Digipeated frames are sent immediately. RAWHDLC and KISS force ACKPRIOR off.<br />
These are the defaults for a P-persistence system with NO Priority<br />
Acknowledgment:<br />
ACKPRIOR OFF, PPERSIST ON, PERSIST 63, SLOTTIME 30,<br />
RESPTIME 0, MAXFRAME 4, FRACK 5<br />
The following are the recommended command settings for Priority Acknowledge:<br />
1200 baud VHF packet 300 baud HF packet<br />
ACKPRIOR ON<br />
ACKPRIOR ON<br />
PPERSIST ON<br />
PPERSIST ON<br />
PERSIST 84 PERSIST 84<br />
SLOTTIME 30 SLOTTIME 8<br />
RESPTIME 0 RESPTIME 0<br />
MAXFRAME 1 - 7 MAXFRAME 1<br />
FRACK 8 FRACK 15<br />
HBAUD 1200 HBAUD 300<br />
VHF ON (or TONE 3) VHF OFF (or TONE 0)<br />
DWAIT doesn't matter DWAIT doesn't matter<br />
Stations using neither the Priority Acknowledge nor the P-persistence schemes<br />
should set DWAIT 73 for 1200 baud and DWAIT 76 for 300 baud work. Stations<br />
using P-persistence but not Priority Acknowledge should set PERSIST and SLOTTIME<br />
to the same values that ACKPRIOR stations are using.<br />
Timewave and TAPR use some different command names to handle P-persistence.<br />
The following table should help with the AEA/TAPR command differences:<br />
TAPR_SLOTS MFJ SLOTMASK AEA_PERSIST Remarks<br />
1 $00 255 Disables slotting<br />
2 $01 127<br />
3 84<br />
4 $03 63 Default setting<br />
6 42<br />
8 $07 31 Very busy channel<br />
12 20<br />
16 $0F 15 Extremely busy channel<br />
64 $3F 3<br />
Timewave products calculate the TAPR ACKTIME value based on the setting of HBAUD.<br />
The TAPR DEADTIME command is analogous to the Timewave SLOTTIME command.<br />
4/91 A-10<br />
From The <strong>N3UJJ</strong>.COM Document Library
Change language