[Xastir-dev] understanding APRS messages from xastir

[Tom Russo]

I should note that while APRS101 is the official "1.0" spec, it has been 
set in stone since 2004, which is so long ago that APRS has had many, many 
additional hacks tacked on since.  Creating the 1.0 spec was a herculean effort
that never got repeated for subsequent revisions.

These tend to be found only in Bob's "addenda" pages and in discussions on
APRSSIG, but many of them were so good (like reply-ack) that they really are
implemented by most codes.

You can find the "1.1" and "1.2" addenda on Bob's web site, http://aprs.org/

http://aprs.org/aprs11.html
http://aprs.org/aprs12.html

On Tue, Oct 26, 2021 at 03:59:10PM -0600, we recorded a bogon-computron collision of the <russo at bogodyn.org> flavor, containing:
> This is the "Reply-Ack" feature.
> 
> 
> It's not part of the 1.0 APRS spec, it's in one of Bob Bruninga's "addenda"
> 
> http://www.aprs.org/aprs11/replyacks.txt
> 
> 
> The short story is that it improves messaging, because the reply to a message
> contains an "ack" of that message.  This is just in case the real "ack" got
> lost.
> 
> On Tue, Oct 26, 2021 at 11:56:22PM +0200, we recorded a bogon-computron collision of the <kristoff at skypro.be> flavor, containing:
> > Hi all,
> > 
> > 
> > I am working on a project to extend the firmware of the TTGO
> > (aprs-over-LoRa) iGate software.
> > https://github.com/on1arf/LoRa_APRS_iGate
> > 
> > 
> > I am currently doing some additional work on the APRS-IS to RF gateway,
> > specially for APRS "Message" packets.
> > 
> > 
> > I am using xastir on my linux laptop to test out my code.
> > (my igate has ON1ARF-12, my linux laptop/xastir has ON1ARF-14)
> > 
> > 
> > A test message I received is this:
> > 
> > ON1ARF-14>APX215,TCPIP*,qAC,NINTH::ON1ARF-12:test 1.2.3.{3y}12
> > 
> > 
> > Can somebody help interpret this message?
> > 
> > Looking at the "APRS 101" document (which I guess can be considered to be
> > the more-or-less official specification for APRS), this seems to be a normal
> > "Message" APRS-message, with message identifier (which should be
> > acknowledged by a reverse "ack" message).
> > 
> > But as I had just previously received a "ack12" in a previous message from
> > the xastir station, it looks like that the "{12" is in fact a repetition of
> > that.
> > 
> > 
> > So, can I interpret this message as a combination of two messages: "test
> > 1.2.3.{3y" and "ack12"
> > 
> > I do not find anything in the "APRS101" document (version 1.0.1 d.d. 29 Aug
> > 2000) that describes this kind of "two-in-one" messages.
> > 
> > So, I am a bit confused why xastir sends this kind of messages packets.
> > 
> > 
> > 
> > Can somebody shed some light on this?
> > 
> > 
> > 73
> > kristoff - ON1ARF
> > 
> > _______________________________________________
> > Xastir-dev mailing list
> > Xastir-dev at lists.xastir.org
> > http://xastir.org/mailman/listinfo/xastir-dev
> 
> -- 
> Tom Russo    KM5VY
> Tijeras, NM  
> 
>  echo "prpv_a'rfg_cnf_har_cvcr" | sed -e 's/_/ /g' | tr [a-m][n-z] [n-z][a-m]
> 
> _______________________________________________
> Xastir-dev mailing list
> Xastir-dev at lists.xastir.org
> http://xastir.org/mailman/listinfo/xastir-dev

-- 
Tom Russo    KM5VY
Tijeras, NM  

 echo "prpv_a'rfg_cnf_har_cvcr" | sed -e 's/_/ /g' | tr [a-m][n-z] [n-z][a-m]