[OZAPRS] Re: Dupes to APRS-IS from VK5

[Richard Hoskin]

Here are a few items that can cause delays in packets.

Note that once the delay in the packet is over time X (not sure of the
value) the APRS-IS system will consider the packet to be a new packet, not a
duplicate.

- Digipeater TNC holding the packet.
- The packet takes more than one route to the IGate and the delay on the
longer route is more than the dup detection timeout on the IGate.
- Some APRS applications (not correctly configured) can transmit a log of an
earlier transmission to RF or ARPS-IS.
- Some IGate applications hold packets for a time before passing them on.
- Some ISPs and / or IP networks can delay data being sent to / from them.
- A combination of the above.

Cheers
Richard
VK3JFK


> -----Original Message-----
> From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] On
> Behalf Of Joseph Burford
> Sent: Thursday, 12 June 2008 12:53 PM
> To: Tony Hunt
> Cc: ozaprs at aprs.net.au
> Subject: [OZAPRS] Re: Dupes to APRS-IS from VK5
> 
> Hi Tony,
> 
> > it.. Its a concern however as its going to potentially cause dupes on RF
> as
> > a time delay like 10 mins will get past the Dupe checks on the servers
> and
> > create what appears to be a new frame on the system comming back onto
> RF..
> 
> Yeah that's my thinking.
> 
> 2008-06-10 17:39:14 UTC: VK5UJ-1>APOT2A,VK5RSC-1*,WIDE2-1,qAo,VK5EX-1
> 2008-06-10 17:52:01 UTC: VK5UJ-1>APOT2A,VK5BRC-1,VK5RLD-1*,WIDE2,qAo,VK5LY
> 
> 13 minutes.
> 
> 2008-06-10 21:19:25 UTC: VK5UJ-1>APOT2A,VK5RNE-1*,WIDE2-1,qAo,VK5EX-1:
> 2008-06-10 21:27:39 UTC: VK5UJ-1>APOT2A,VK5RMB-1,VK5RLD-1*,WIDE2,qAo,VK5LY
> 
> 8 minutes.
> 
> 2008-06-10 23:19:35 UTC: VK5UJ-1>APOT2A,VK5RNE-1*,WIDE2-1,qAo,VK5EX-1
> 2008-06-10 23:23:53 UTC: VK5UJ-1>APOT2A,VK5RMB-1,VK5RLD-1*,WIDE2,qAo,VK5LY
> 
> 4 minutes.
> 
> It could have been in the APRS-IS, although I struggle to see where
> you would find that delay between the end client and the server or
> between servers.
> 
> It also seemed like maybe VK5RLD-1 wasn't digipeating straight away,
> maybe hodling onto the packets it heard because something was holding
> DCD/Squelch open or similar. Could have been something local
> happening.
> 
> Anyway it's been good for about 24 hours now, so touch wood :)
> 
> > there was an explanation.. I wonder what server Larry is logged into on
> 5LY
> > as compared to Andrews login on 5EX ?? Is there some sort of delay in
> the
> 
> If I recall, one was on first.aprs.net.au, the other on second.aprs.net.au
> 
> > Instead of WIDE2-2 try ADEL2-2 . This will stop your frames propagating
> into
> > the Riverland 5RLD system and getting heard by Larrys system.. Its will
> only
> > goto RMB BRC RNE RSC ..
> 
> Might give an alternatiing beacon a go, switch the path for each beacon.
> 
> With WIDE2-2 it's interesting to see how 1watt often hits RAC and RLD
> directly :-)
> 
> Cheers,
> 
> Joseph
> 
> --
> http://www.josephburford.com
> _______________________________________________
> Ozaprs mailing list
> Ozaprs at aprs.net.au
> http://aprs.net.au/mailman/listinfo/ozaprs

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