[nos-bbs] Collision avoidance

[Steven Stimpson]

  ----- Original Message ----- 
  From: George (Skip) VerDuin 
  To: TAPR xNOS Mailing List 
  Sent: Friday, August 11, 2006 10:40 AM
  Subject: Re: [nos-bbs] Collision avoidance


  Actually - I don't mind the wait to get a 1/2 second opening to jump into.
  My trouble is not waiting...

  This is a side-light information...
  I found some distressing frames I don't know how to produce even if I tried.
  MAXFRAME allows packing multiple packets into a frame / however / I see multiple repeats of the SAME packet in a frame.
  This smells BAD to me. 


   SKIP:

   1/2 second is too short, that is shorter than most SLOT times and TXD will allow,
  as a matter of fact a lot of people use an actual TXD greater than 1/2 second.
  1/2 second between transmissions is way too short, IN short, they
  are "Hogging" the frequency using aggressive timings. In other
  words YOU have seen the light of day and are going to use persist and slots.
   If the time between thier tx is really that short, they are using neither.



  The repeat Packets. I have been complaining about this for years with KISS. The
  fault is not JNos or your Tnc, it is the fact that the ax.25 protocol is seperated
  from the tnc and resides in your computer. the computer does not know that your
  tnc has been waiting 5 seconds to transmit frame number one, so IN
  the computer the frack timer expires, and the computer sends it again. your only solution
  is to set a really high frack timer. this will slow things down, but will stop
  the DUP frames. I use KISS mainly on H.F. and the wait times, at 300 baud,
  between frames can be great, and we run into this problem a lot. This problem
  would also be solved if the TX'ing stations would reduce maxframe and paclen.

  the problems you are running into with slots, persist, and frack>kiss expiry are
  all symptoms of an EXTREMELY busy frequency, or if only a couple stations
  are present, some rather rude Parms are in place.

I see no evidence of duplication thus FRACK may be OK... 




  Look up ^^^^^ you said you are seeing multiple dupes in the same
  "Frame".  A frame and a "Packet" are the same thing. the multiple
  packets you are seeing sent to the tnc is a matter of
  the kiss protocol. if you have maxF set greater to one,
  say, rudely, to four, then your jnos, in KISS< will send four
  Frames in one Burst to the tnc. If you are seeing more than one
  of the same "frame" or "Packet" in the same burst then the frack timer is
  indeed too short for the channel conditions. Channel conditions depending
  on how many folks or how polite the channel users are being.


   Only trying to help so please don't tell me to "remove the bananna" this time :-) :-)

  Steven N1OHX
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