[OZAPRS] Strange APRS packets

[Philip Webb]

Gentlemen,

Actually, I'm glad this subject has come up, because I have been 
noticing issues for a while and not sure how to broach the subject.

Out here in the country, I often see posits going straight to tcpip only 
- no problem. Occasionally I see a mixture of both, and most of the time 
that is understandable. But occasionally I see things that don't make 
any sense.

Neither my car nor David's is fitted with 3G mobile yet many of our trip 
have posits marked as TCPIP with the original VHF path lost - short 
example below.

2011-12-02 13:17:38 UTC: 
VK4HPW-9>APT311,VK2RAP-3,WIDE1*,WIDE2-2,qAR,VK4HPW-1:!2801.97S/15228.01E>241/042/A=000823
2011-12-02 13:17:38 UTC: 
VK4HPW-9>APT311,VK2RAP-3,WIDE1*,WIDE2-2,qAR,VK4HPW-1:>VK4HPW/Mobile
2011-12-02 13:19:38 UTC: 
VK4HPW-9>APT311,TCPIP*,qAS,VK4OG-1:!2802.42S/15226.90E>238/027/A=001046
2011-12-02 13:21:37 UTC: 
VK4HPW-9>APT311,TCPIP*,qAS,VK4OG-1:!2803.17S/15226.25E>239/043/A=001348

The TCPIP packets are always attributed to VK4OG and has only been 
happening recently.

I also noted anomalous activity similar to David's on Saturday 24 th, 
with the duplicate "position" packets and posits moving too fast - but I 
won't spell out any further details except to say that the anomalous 
packets are also related to VK4OG and VK4VP.
I have analysed some of the duplicate "position" packets, and they have 
been repeated up to 6 minutes later than the originals and have 
"WIDE1*,WIDE2-2" modified to "WIDE1,WIDE2*".

If anyone would like to have a look at the chapter and verse, please 
contact me off list.

I'm just trying to help sort out a fine system which has been working 
well up to now.

Tried your site Damien, but it timed out and I did get my data from aprs.fi

I hope you all have a great New Year.

73

Philip
VK4HPW



On 26/12/11 18:40, Damien Gardner Jnr wrote:
> I'm guessing that you're referring to the 'duplicate position packet'
> messages?  You didn't actually say what the 'strange behaviour' actually was
> :)
> That would appear to be a problem upstream from .au, as it's *not* appearing
> on the second.aprs.net.au data stream..  Check out
> http://hamtrack.pinegap.net/stationdump.php?stationid=42434 for your raw
> packet dump for the last 24 hours - you'll see that there were no duplicates
> in there, so any 'duplicates' that aprs.fi may have seen, were in the global
> network, not .au..
>
> Cheers,
>
> DG
> -----Original Message-----
> From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] On
> Behalf Of David Hopkins
> Sent: Monday, 26 December 2011 2:15 PM
> To: ozaprs at aprs.net.au
> Subject: [OZAPRS] Strange APRS packets
>
> Gentlemen,
> Anyone else noticed strange behavior on the APRS system here,
>
> Have a look at the raw packets on VK4zf-9 on aprs.fi At first I thoughht
> there was something wrong with the setup in this car.
>
> However if you look at vk4zf-7, it has the same problem.This is a completely
> different car and radio.
> I have noticed it also on other mobiles.
>
> If you watch the tracks on aprs.fi the positions are all over the place.
>
> What is going on?
>
> David
>
>
> David G. Hopkins (VK4ZF)
> CAPALABA QLD
> AUSTRALIA
> 27.32.38S 153.12.03E
> QG62OL
> Skype :- davhop
>
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