[aprssig] APRS-IS Duplicate Packets

[Tapio Sokura]

On Mon, May 3, 2010 23:57, Pete Loveall AE5PL Lists wrote:
> level software -never- alters the transported data.  It is a bad design
> from day one for anyone to consider that it is "ok" to ignore data in a

I think we are way past the "bad design" (and bad implementation) phase in
APRS(-IS). Currently what is left, to put it bluntly, is largely damage
control. It is a fact that the network includes a lot of igates and maybe
also digipeaters that break packets that pass through them, one way or
another. They won't be going away anytime soon, even if all new or updated
software behaves ideally in every way.

To get the best compromise from what we have left, we sometimes might need
to deviate from the ideal. I.e. here we might choose to drop the duplicate
packets instead of letting them through. I'm not saying it's the correct
thing to do wrt the Yaesu VX-8, but I can understand if someone is doing
it. You lose the device identification, but gain some more "air time".
Also note that nowhere did I write that the packets themselves would be
modified, just the checksumming for duplicate detection.

  Tapio