[aprssig] KJ4GQV ClusterBalloon Flying

Matti Aarnio oh2mqk at sral.fi
Sat Jul 31 14:45:39 CDT 2010

On Fri, Jul 30, 2010 at 10:57:38AM -0400, Robert Bruninga wrote:
> > Above altitude of 3000 feet one should use at 
> > most WIDE1-1, preferrably no via paths at all.  
> >> Bob should really write some new guidance 
> >> on path definitions for flyers.
> The recommendation has never changed in the last decade.
> NEVER-EVER USED WIDE1-1 !!!!  There is no DUPE suppression in
> APRS for WIDE1-1!.

What?  Is my APRS digipeater code wrong as it treats all  WIDEn-N
constructs the same and does dupe suppression on them all?

For that matter, I do duplicate suppression on _all_ APRS packets
relayed by all of the relaying modes in the system, interface aliases
included.   But my code is special in recognizing APRS packets with
PID value, and not only as "these are AX.25 UI frames".
(All other type of PDUs are treated in classical digipeater with
interface callsign/alias rules.)

> If a DIGI is causing dupes, FIX THE DIGI!  Update to the 2004
> New-N Paradigm!!!

New-N is happening, but "timeslot fracticide" is not very common thing
from observations of what happens with flying trackers.

Mostly digis are delaying transmissions until the channel is quiet.
They also hold on packet tx queue content for _infinite_ time.
This is also true for most (all?) KISS TNCs!

Looks like most of the TNCs/digis do not have any concept of "packet
timed out while in tx queue".   If a packet is on tx queue waiting for
quiet time on channel to get a transmission slot, it should be killed
from queue if it has waited for more than N seconds.

What would be good value for N?  Ten?

> Bob, Wb4APR

73 de Matti, OH2MQK

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