[aprssig] Whazzuuuuuuuuup!

VE7GDH ve7gdh at rac.ca
Sun Jan 8 13:17:17 EST 2006

Pete AE5PL wrote on Jan 8 2006

> First, any dupe checking longer than the default of 30 seconds on
> APRS-IS would potentially interfere with messaging and other fixed
> packet operations.

I hadn't thought about messages, but what would the impact be to them if
dupe checking was extended beyond 30 seconds? Could separate algorithms be
applied to position beacons than other traffic?

You would kind of think that with (most) people using shorter paths now, the
"normal" out of order packets that I see in my vicinity would be reduced,
but I still see it from time to time. What I saw yesterday (I12 minutes) was
more extreme than anything I had seen before - plus DG0ES isn't exactly
within earshot of where this was taking place.

> Second, it appears that there is something very strange in
> DG0ES's setup.  He is running UI-View and the packets being repeated are
> actually from APRS-IS (note the two occurrences of the qAo construct).

I noticed the two Q constructs, but hadn't thought it through properly. The
beacon heard by VE7CUU properly showed qAo. The ones "re-gated" by DG0ES
were "QAO,VE7CUU,qAO,DG0ES" and "QAO" doesn't even show up at
www.aprs-is.net/q.htm .

> The first qAo is converted to all upper case which tells me that this
> may be a log file replay?  Or his UI-View is connected to a full stream
> and is looping the packets back to APRS-IS after significant processing
> delays?  I am sure my list is not all-inclusive.

I remember some time ago when someone suggested that "some" APRS clients
effectively gated log files that were being played back. I use UI-View32 and
intentionally played back some day-old logs and saw no evidence that it was
gating the output of the log file. I don't know if DG0ES is getting the data
for VE7CUU-14 via TCPIP or by other means, but it wasn't apparent to me that
there was an RF station ahead of DG0ES that was involved.

Just for the record, here are the two beacons retrieved from findu.com that
were responsible for the first "12 minute back in time" zig-zag that I
noticed yesterday.

The original one gated by VE7CUU...

VE7CUU-14>TY5SWQ,WIDE2-2,qAo,VE7CUU:`3,.o5 k/"41}

and the later one from DG0ES...

VE7CUU-14>TY5SWQ,WIDE2-2,QAO,VE7CUU,qAO,DG0ES:`3,.o5 k/"41}

> So, try sending an email to DG0ES and let him know what is happening
> as this is definitely a problem with his station.

So far, I have only tried an APRS message and that hasn't been acked.
However, DG0ES hadn't been heard for about two hours before I sent my
message. However, I just checked and that station was active as recently as
27 minutes ago.

Just tried pinging, querying and sending the DX command to DG0ES and no 
response to any of them.

73 es cul - Keith VE7GDH
"I may be lost, but I know exactly where I am!"

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