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Okay, this goes against what little I have learned about VoIP
traffic.<br>
<br>
I didn't think there was any FEC with voice. That's why voice has
priority on data networks that use VoIP. Otherwise, if a data
packet has priority, it would bump a voice packet. When a voice
packet is bumped, you lose bits of it resulting in choppy audio.<br>
<br>
I have experienced this when some of our first quasi VoIP locations
came online. Voice is live traffic. Once it is said, it goes.
There's nothing to re-transmit.<br>
<br>
Without getting into the engineering (which will leave me drooling
and nodding off to sleep), how does D-STAR use FEC on voice?<br>
<br>
73,<br>
Joel - W4JBB<br>
<br>
<div class="moz-cite-prefix">On 9/20/13 3:57 PM, John Davis wrote:<br>
</div>
<blockquote
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<div class="WordSection1">
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">That
is true. The FEC is on the voice with 2400 bits for voice
and 1200 for FEC.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">John
WB4QDX<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif"">From:</span></b><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif"">
<a class="moz-txt-link-abbreviated" href="mailto:drats_users-bounces@intrepid.danplanet.com">drats_users-bounces@intrepid.danplanet.com</a>
[<a class="moz-txt-link-freetext" href="mailto:drats_users-bounces@intrepid.danplanet.com">mailto:drats_users-bounces@intrepid.danplanet.com</a>]
<b>On Behalf Of </b>Daniel Metcalf<br>
<b>Sent:</b> Friday, September 20, 2013 4:55 PM<br>
<b>To:</b> Discussion of D-RATS<br>
<b>Subject:</b> Re: [drats_users] ERROR Correction in slow
speed data<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p>Agreed. From what I have read d-star is a lot like the UDP
network protocol where it is transmit and forget there is no
handshaking / error correction built in. It is up to the
application developer to handle error correction and the
d-rats package does perform some level of error correction.<o:p></o:p></p>
<p>Dan Metcalf - KB3UUN.<o:p></o:p></p>
<div>
<p class="MsoNormal">On Sep 20, 2013 3:54 PM, "John Davis"
<<a moz-do-not-send="true"
href="mailto:jdavis@gtworks.com">jdavis@gtworks.com</a>>
wrote:<o:p></o:p></p>
<blockquote style="border:none;border-left:solid #CCCCCC
1.0pt;padding:0in 0in 0in
6.0pt;margin-left:4.8pt;margin-right:0in">
<div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">My
understanding is that the low speed data channel
does NOT have error correction, however, D-RATS
offers Error correction in Message and File Transfer
modes where it is most important.</span><o:p></o:p></p>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">John
WB4QDX</span><o:p></o:p></p>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> </span><o:p></o:p></p>
<div>
<div style="border:none;border-top:solid #E1E1E1
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif"">From:</span></b><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif"">
<a moz-do-not-send="true"
href="mailto:drats_users-bounces@intrepid.danplanet.com"
target="_blank">drats_users-bounces@intrepid.danplanet.com</a>
[mailto:<a moz-do-not-send="true"
href="mailto:drats_users-bounces@intrepid.danplanet.com"
target="_blank">drats_users-bounces@intrepid.danplanet.com</a>]
<b>On Behalf Of </b>Dave Welker<br>
<b>Sent:</b> Friday, September 20, 2013 3:19 PM<br>
<b>To:</b> D-Rats Mailing List<br>
<b>Subject:</b> [drats_users] ERROR Correction
in slow speed data</span><o:p></o:p></p>
</div>
</div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">Hello all,</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">Can anyone
confirm if the D-RATS slow speed data has FEC
(Forward Error Correction) built in now or not?</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">I understand
that D-STAR voice does have error correction built
in. I've checked on the D-RATS home
page/documentation</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">which is a
August 2009 reference.</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">This is what
I found in this document Under users
manual/files: Is this still current information?</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p
style="margin:0in;margin-bottom:.0001pt;background:white;word-spacing:0px"><strong><span
style="font-family:"Verdana","sans-serif";color:#666666">Unlike
the D-STAR DV Voice Channel, which has error
correction built into the protocol, the Data
Sub-channel has no error correction. </span></strong><o:p></o:p></p>
<p
style="margin:0in;margin-bottom:.0001pt;line-height:11.25pt;background:white;word-spacing:0px"><span
style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:#666666"> </span><o:p></o:p></p>
<p
style="margin:0in;margin-bottom:.0001pt;background:white;word-spacing:0px"><strong><span
style="font-family:"Verdana","sans-serif";color:#666666">This
makes the transfer of data across D-STAR a lot
more dependant on a good radio path being
established between the two locations wishing to
</span></strong><o:p></o:p></p>
<p
style="margin:0in;margin-bottom:.0001pt;line-height:11.25pt;background:white;word-spacing:0px"><span
style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:#666666"> </span><o:p></o:p></p>
<p
style="margin:0in;margin-bottom:.0001pt;background:white;word-spacing:0px"><strong><span
style="font-family:"Verdana","sans-serif";color:#666666">exchange
data. D-RATS includes the ability to test
connectivity between two locations</span></strong><strong><span
style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:#666666">.</span></strong><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">Thanks in
advance</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">regards</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">Dave</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">W2SRP</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">Goals are
where we want to be;<br>
Objectives are the steps to get there.</span><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span
style="font-family:"Century
Gothic","sans-serif"">There are 2
rules to success in life:<br>
1. Don't tell people everything you know.</span><o:p></o:p></p>
</div>
</div>
</div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><br>
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target="_blank">http://intrepid.danplanet.com/mailman/listinfo/drats_users</a><o:p></o:p></p>
</blockquote>
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