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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=k8rra@ameritech.net href="mailto:k8rra@ameritech.net">George (Skip)
VerDuin</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=nos-bbs@lists.tapr.org
href="mailto:nos-bbs@lists.tapr.org">TAPR xNOS Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, August 13, 2006 1:21
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [nos-bbs] Collision
avoidance</DIV>
<DIV><FONT face=Arial size=2></FONT><FONT face=Arial size=2></FONT><BR></DIV>
<DIV>Hey Steve - I need to be very accurate in this and can not take the
chance of mis-interpreting your input...<BR><BR>>SNIP< </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> HI skip. Here is a snippet from my
autoexec.nos The parm is AX25 IRTT, Initial Round Trip Timer.</FONT></DIV>
<DIV><FONT face=Arial size=2>These are VHF parms.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>#</FONT></DIV>
<DIV><FONT face=Arial size=2>ax25 timertype orig<BR># Initial rtt for ax25
(FRACK) is 4 secs. (Works out to abt 4-8 sec actually)<BR>ax25 irtt 4000<BR>#
RespTime in ms<BR>ax25 t2 5<BR># Check Time in ms (450 secs 1/2 of
No-Activity)<BR>ax25 t3 950000<BR># No-Activity Time in Secs<BR>ax25 t4
180000</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Note my t3 and t4 settings are absurd, this was
to hold a link with</FONT></DIV>
<DIV><FONT face=Arial size=2>a packetcluster around the clock some time ago.
Check the docs</FONT></DIV>
<DIV><FONT face=Arial size=2>for setting on those, or do what ka1nnn says here
and start with 450 for t3,</FONT></DIV>
<DIV><FONT face=Arial size=2>and double that for t4. Also, since we owned the
freq, my</FONT></DIV>
<DIV><FONT face=Arial size=2>Resp timer is rude. ax25 timertype is a method of
backing</FONT></DIV>
<DIV><FONT face=Arial size=2>off the frack timer with each missed frame. Never
tried</FONT></DIV>
<DIV><FONT face=Arial size=2>it with VHF but on H.F. it can reach epic
proportions</FONT></DIV>
<DIV><FONT face=Arial size=2>and is no good.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV>In addition, can you confirm that entering kiss mode locks out the TNC
frack timer so there is no timer-race?</DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV><FONT face=Arial
size=2></FONT></BLOCKQUOTE>
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<DIV><FONT face=Arial size=2> Sure. The frack timer is a function of the
Level2 firmware that resides in</FONT></DIV>
<DIV><FONT face=Arial size=2>the tnc. This is all disabled when entering KISS.
Level 2 is run</FONT></DIV>
<DIV><FONT face=Arial size=2>in the computer, and is sent with each frame as a
KISS header.</FONT></DIV>
<DIV><FONT face=Arial size=2>TXD, RESP, DWAIT, FRACK and I believe TXTAIL are
all</FONT></DIV>
<DIV><FONT face=Arial size=2>handled by your KISS app. Note I said believe. I
have</FONT></DIV>
<DIV><FONT face=Arial size=2>experimented with all these from the MSYS
command</FONT></DIV>
<DIV><FONT face=Arial size=2>console and they can be changed on a per packet
basis.</FONT></DIV>
<DIV><FONT face=Arial size=2> But I bet some of the programmers could
tell you for sure which ones</FONT></DIV>
<DIV><FONT face=Arial size=2>are and aren't. I'm not entirely sure what you
mean by timer race?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT><FONT face=Arial size=2></FONT><FONT
face=Arial size=2></FONT><FONT face=Arial size=2></FONT><BR></DIV>
<BLOCKQUOTE TYPE="CITE">
<BLOCKQUOTE><FONT face=Arial size=2></FONT> </BLOCKQUOTE></BLOCKQUOTE>
<DIV>>From your experience, could you pass on the set of all (TNC and
software) parameters that work well together at 300B HF kiss</DIV>
<DIV> >SNIP< </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> On some of the extremely busy nets, a frack
timer of 11 seconds...Yes, eleven seconds, would</FONT></DIV>
<DIV><FONT face=Arial size=2>keep frames from backing up in the tnc. You also
need to add the time it takes to</FONT></DIV>
<DIV><FONT face=Arial size=2>transmit the frame into account, since the frack
timer starts counting</FONT></DIV>
<DIV><FONT face=Arial size=2>in the computer the moment the frame leaves the
computer. If it takes</FONT></DIV>
<DIV><FONT face=Arial size=2>5 seconds to TX the frame but frack is only 4,
there is going to be problems.</FONT></DIV>
<DIV><FONT face=Arial size=2>If you have to wait 4 seconds for the frequency
to clear</FONT></DIV>
<DIV><FONT face=Arial size=2>and then another five while you TX, there is
going to be bigger problems.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> Another parm to watchout for is PTHRESH.
Poll threshold. If your paclen</FONT></DIV>
<DIV><FONT face=Arial size=2>is 64, and pthresh is not set, each time the
frack timer expires</FONT></DIV>
<DIV><FONT face=Arial size=2>the whole 64 length frame will be sent over and
over. much better</FONT></DIV>
<DIV><FONT face=Arial size=2>to send a poll then the entire frame. A friend of
mine</FONT></DIV>
<DIV><FONT face=Arial size=2>solved this by setting paclen to 64 and pthresh
to 62.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> If you want to see all this in action set
your frack to 1/2 second,</FONT></DIV>
<DIV><FONT face=Arial size=2>TXD to one second, paclen to 255, disable
pthresh, set your retry</FONT></DIV>
<DIV><FONT face=Arial size=2>to 10, and connect to a buddy on a clear
freq. send a big</FONT></DIV>
<DIV><FONT face=Arial size=2>frame and it should crash and burn
:-)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> I went to wa8ded firmware some time ago. It
like half-kiss, and half-TNC.</FONT></DIV>
<DIV><FONT face=Arial size=2>level2 resides in the tnc, and all the timers
know the state of the DCD.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>GL, hope this isn't TMI but it's raining out and
there is nothing to do :-)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Steven</FONT></DIV>
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