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<div class="moz-cite-prefix">K4FHK-10>APRX27,TCPIP*,qAC,FIFTH:>Originator
of TNMVA objects. Send comments to <a class="moz-txt-link-abbreviated" href="mailto:tnmva@knobbe.us">tnmva@knobbe.us</a><br>
<br>
<img src="cid:part1.04070109.05040207@homeside.to" alt=""><br>
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Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and
Win32<br>
<br>
On 11/7/2015 4:17 PM, Andrew P. via aprssig wrote:<br>
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<div dir="ltr">Greetings.<br>
<br>
I've noticed an unusual new experimental tocall value APZMVA,
that seems to be associated with some oddly formatted APRS-IS
messages. I was just curious what that might be.<br>
<br>
Regarding the unusual formatting (which probably has nothing to
do with the APZMVA program, as I am seeing from other tocalls as
well), I am seeing packets from the APRS-IS that look like this:<br>
<br>
K4FHK-15>APZMVA:K4FHK-15>APZMVA,TCPIP*,qAS,K4FHK-IS:;TNMVA64a2_072105zI</yn8U#*n
__I-65-N DEBRIS, LEFT LNS BLOCKED<br>
<br>
Note that the sender>tocall section is repeated twice, with a
colon (':') delimiting the two occurrences. I'm wondering if
this might be an issue with some dialects of the APRS-IS server
code (specifically aprsc, since it is the one that shows up for
every I-gate I've back-tracked), should my application not be
reading the TCP socket connection fast enough, that the server
might get the first part of a message stuffed in the stream, and
then discards the rest of the message because of a TCP window
overflow. That would make this appear like two concatenated
messages with most of the first message gone, including the CRLF
delimiter between the two messages. I've got a 48Kb TCP window
size configured in my application, so there should be plenty of
kernel-level buffering to allow for any pauses at the
application level.<br>
<br>
The occurrence doesn't seem to be a function of the incoming
message rate.<br>
<br>
Anybody have any ideas what's going on? Or is this a new format
of I-gated messages from some I-gates? Note that some of the
offending I-gates are UIView, so it can't be anything new
(because other UIView I-gates aren't doing this).<br>
<br>
Any suggestions would be welcome.<br>
<br>
Andrew Pavlin, KA2DDO<br>
author of YAAC ("Yet Another APRS Client")<br>
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