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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Are we over-thinking this situation?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>It occurs to me that it may be a
combination of things, all contributing to a built-in delay, which may be characteristic
of the IS system. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Based on recent messages, both here and on
the UI-View list, there seem to be two concerns:<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:.75in;text-indent:-.5in;mso-list:l0 level1 lfo1'><![if !supportLists]><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'><span style='mso-list:Ignore'>1.<font size=1 face="Times New Roman"><span
style='font:7.0pt "Times New Roman"'>
</span></font></span></span></font><![endif]><font size=2 color=navy
face=Arial><span style='font-size:10.0pt;font-family:Arial;color:navy'>A delay
between the times a beacon is sent out from an APRS station via RF to when it’s
seen on APRS IS<o:p></o:p></span></font></p>
<p class=MsoNormal style='margin-left:.75in;text-indent:-.5in;mso-list:l0 level1 lfo1'><![if !supportLists]><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'><span style='mso-list:Ignore'>2.<font size=1 face="Times New Roman"><span
style='font:7.0pt "Times New Roman"'>
</span></font></span></span></font><![endif]><font size=2 color=navy
face=Arial><span style='font-size:10.0pt;font-family:Arial;color:navy'>Tracked
objects “jumping” back some distance<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>The delay may be caused by the time lag
between a packet going out at 1200 baud, going from the TNC to the computer at
9600 baud, being picked up by an RF-Internet gateway, going to the server at
much higher b/s rates, crammed into the server’s buffer, then sent out on
the Internet to each station connected, some of which are not range-filtered,
and finally sent from the computer at whatever rate the client NIC/computer
sends it to the screen. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Also, here is a recent log of activity of
my station alone, from the T2 Midwest server. Range filtered at 300km:<o:p></o:p></span></font></p>
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'>Packets
for W9JBL<br>
Time in UTC<o:p></o:p></span></font></p>
<table class=MsoNormalTable border=1 cellpadding=0>
<tr>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>8/26/2006 13:20<o:p></o:p></span></font></pre></td>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>W9JBL>APU25N,WA9CJN-15*,IL2-1,qAo,WB9WLS:=4155.50N/08845.11W- {UIV32N}<o:p></o:p></span></font></pre></td>
</tr>
<tr>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>8/26/2006 13:24<o:p></o:p></span></font></pre></td>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>W9JBL>APU25N,WA9CJN-15*,IL2-1,qAR,W9TMW:=4155.50N/08845.11W- {UIV32N}<o:p></o:p></span></font></pre></td>
</tr>
<tr>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>8/26/2006 13:34<o:p></o:p></span></font></pre></td>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>W9JBL>APU25N,TCPIP*,qAC,T2MIDWEST:=4155.50N/08845.11W- {UIV32N}<o:p></o:p></span></font></pre></td>
</tr>
<tr>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>8/26/2006 13:36<o:p></o:p></span></font></pre></td>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>W9JBL>APAGW,WA9CJN-15,WIDE2*,qAS,N9ZIP:Using Elcom uTNT Plus<o:p></o:p></span></font></pre></td>
</tr>
<tr>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>8/26/2006 13:39<o:p></o:p></span></font></pre></td>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>W9JBL>APU25N,TCPIP*,qAC,T2MIDWEST:=4155.50N/08845.11W- {UIV32N}<o:p></o:p></span></font></pre></td>
</tr>
<tr>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>8/26/2006 13:43<o:p></o:p></span></font></pre></td>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>W9JBL>APU25N,TCPIP*,qAC,T2MIDWEST:=4155.50N/08845.11W- {UIV32N}<o:p></o:p></span></font></pre></td>
</tr>
<tr>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>8/26/2006 13:44<o:p></o:p></span></font></pre></td>
<td style='padding:.75pt .75pt .75pt .75pt'><pre><font size=2
face="Courier New"><span style='font-size:10.0pt'>W9JBL>APU25N,TCPIP*,qAC,T2MIDWEST:=4155.50N/08845.11W- {UIV32N}<o:p></o:p></span></font></pre></td>
</tr>
</table>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>As the log shows, some packets are picked
up directly by the server, others are received after one AND two hops. Unless
the server is reliably filtering out ALL dupes, this may account for the
jumping I saw in W9JBL-9 last weekend, where a late beaconed tracker packet hit
the client computer, containing GPS data made the icon regress to where the
prior beacon located it.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Just a thot/question.<o:p></o:p></span></font></p>
<div>
<p><font size=2 color=navy face="Times New Roman"><span style='font-size:10.0pt;
color:navy'>bl<br>
------------------------------------<br>
"If stupidity got us into this mess, then why can't it get us out?"<br>
- Will Rogers </span></font><o:p></o:p></p>
</div>
<div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'>
<div>
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face="Times New Roman"><span style='font-size:12.0pt'>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
aprssig-bounces@lists.tapr.org [mailto:aprssig-bounces@lists.tapr.org] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Wes Johnston, AI4PX<br>
<b><span style='font-weight:bold'>Sent:</span></b> Friday, August 25, 2006
10:04 PM<br>
<b><span style='font-weight:bold'>To:</span></b> TAPR APRS Mailing List<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [aprssig] Delayed
packets (yet again)</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Recently kc4pl and I saw enormous delays on RF. We've seen igate
delays from ww6jc in a nearby town running ui-view. At anyrate,
kc4pl is running TNC-x and an ax.25 stack connected to javaaprs.
What we saw was /were delays on the order of 60 to 90 seconds. I was
sending packets that were uniquely numbered so we'd know which got thru and
which didn't. <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>We suspected that perhaps TNCx was hearing too many packets on
frequency to TX, so he QSY'ed the radio. I send a few more packets.
Then it dawned on us that he wasn't seeing the packets I send for 60 to 90
seconds. As soon as he saw them appear in the ax.25 stack, they were
digipeater. In the process of reaching under the desk, he may have reset
or momentarly interrupted the power to the TNCx.... so we're not sure if the
tnc-x is the problem or the ax.25 stack in linux. Or maybe some part of
the system needed a break. At this time, we're waiting for the delays to
happen again so we can figure out if it's TNC-x or ax25 stack. <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Possible theories include that TNCx may have a memory leak...<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>tncx may spend so much time servicing interrupts in a busy channel that
it can't deliver data to the serial port.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>ubuntu ax25 may have a problem.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
Really don't know anything difinitive at this point.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Wes<br>
<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><span class=gmailquote><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>On 8/25/06, <b><span style='font-weight:bold'>Tim
Cunningham</span></b> <<a href="mailto:tim_cunningham@mindspring.com">tim_cunningham@mindspring.com</a>>
wrote:</span></font></span> <o:p></o:p></p>
<div>
<div bgcolor="#ffffff">
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>There was a delayed packet discussion specifically
concerning IGates recently. We did a through study into the problem in my area
and isolated the problem to a UI-View station operating as an IGate. Since that
discussion there were a few other folks across the country who wrote off-line
that they experienced the same issue with UI-View in their areas. This issue
was specifically limited to a UI-View IGate that was injecting packets greater
than 1 minute later than another IGate using APRS+SA. Many of the packets were
time stamped to verify the delay. It was not a digipeater delay because we
could see two IGates hearing the same packet from the same digipeater being
injected into the APRS-IS greater than one minute apart. </span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>IGates that are experiencing delays should consider using
filtered port 14580 and limit their data to under 100 to 200km using the
m/100 to m/200 qualifier. When an IGate tries to process the full feed
they are going to run slower depending on their computer configuration and
whether they are using a dial-up feed or a high speed link. </span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>There are many sources of delays that also include
digipeaters. The first step is to identify if the delay is the USB to serial
converter which should be fairly easy by visual observation on how long it takes
a decoded packet to appear on the screen. Then, it becomes only a measure of
time from that point to when it appears on the APRS-IS. </span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>73's,</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Tim - N8DEU</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><st1:place w:st="on"><st1:City w:st="on"><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'>Huntsville</span></font></st1:City><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'>, <st1:State
w:st="on">Alabama</st1:State></span></font></st1:place><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
</div>
<div>
<div>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>----- Original Message ----- <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal style='background:#E4E4E4'><b><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial;font-weight:bold'>From:</span></font></b><font
size=2 face=Arial><span style='font-size:10.0pt;font-family:Arial'> <a
href="mailto:w0jrt@yahoo.com" target="_blank" title="w0jrt@yahoo.com">J T</a> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>To:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> <a
href="mailto:aprssig@lists.tapr.org" target="_blank"
title="aprssig@lists.tapr.org">TAPR APRS Mailing List</a> <o:p></o:p></span></font></p>
</div>
</div>
<div>
<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>Sent:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> Friday, August 25,
2006 1:26 PM<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><b><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial;font-weight:bold'>Subject:</span></font></b><font size=2
face=Arial><span style='font-size:10.0pt;font-family:Arial'> [aprssig] Delayed
packets (yet again)<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
<o:p></o:p></span></font></p>
</div>
</div>
<div><span id="q_10d480ec705d579f_3">
<p class=MsoNormal><span class=e><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>In one of the many "delayed packet"
discussions there was talk about some serial-to-USB converters causing
issues. I can't seem to find this discussion in the archives. Does
anyone recall the make(s)/model(s) of the serial-to-USB converters that are
known or suspected of being problematic? And perhaps suggest a model that
is known to work well? </span></font></span><br>
<br>
<span class=e>I've been communicating with an I-gate owner whose station is
injecting delayed packets into APRS-IS. He's too busy to study and fix
the problem (unfortunately for the rest of us) so I'm trying to help gather
some information that may make it easier to debug the problem. He swapped
TNCs but that didn't fix it. He mentioned that he uses a serial-to-USB
converter so hopefully I can talk him into experimenting with a different one
or coming up with another solution. </span><br>
<br>
<span class=e>-Jerome, W0JRT</span><br>
<br>
<o:p></o:p></p>
</div>
</span>
<div><span id="q_10d480ec705d579f_5">
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size=3 face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=1 width="100%" align=center>
</span></font></span></div>
<p class=MsoNormal><span class=e><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'><a
href="http://us.rd.yahoo.com/evt=43256/*http:/advision.webevents.yahoo.com/mailbeta"
target="_blank">All-new Yahoo! Mail </a>- Fire up a more powerful email and get
things done faster. </span></span></font></span><o:p></o:p></p>
</div>
<div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center>
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