<html>
  <head>
    <meta content="text/html; charset=ISO-8859-1"
      http-equiv="Content-Type">
  </head>
  <body text="#000000" bgcolor="#FFFFFF">
    <div class="moz-cite-prefix">A quick update on this - I have
      verified that suppresion of silence suppression(!) on Grandstreams
      doesn't work when it is the B-Party of a call. I'm not sure if
      silence-suppression is part of the SIP handshake, but I know that
      other VOIP technologies seem to be able to prevent it.<br>
      I'm calling in a handset specialist to advise..<br>
      <br>
      One of the things that intrigues me is this extract from the log
      (particularly the reference to silenceSupp):<br>
      <br>
      2013-02-27 17:28:05.151624 [DEBUG] switch_core_codec.c:244
      <a class="moz-txt-link-abbreviated" href="mailto:sofia/internal/0253302@004-0253.sb12.dmclub.org">sofia/internal/0253302@004-0253.sb12.dmclub.org</a> Restore previous
      codec PCMA:8.<br>
      2013-02-27 17:28:05.151624 [DEBUG] mod_sofia.c:754 Local SDP
      <a class="moz-txt-link-abbreviated" href="mailto:sofia/internal/0253302@004-0253.sb12.dmclub.org">sofia/internal/0253302@004-0253.sb12.dmclub.org</a>:<br>
      v=0<br>
      o=FreeSWITCH 1361975871 1361975873 IN IP4 176.58.88.201<br>
      s=FreeSWITCH<br>
      c=IN IP4 176.58.88.201<br>
      t=0 0<br>
      m=audio 10212 RTP/AVP 8 101<br>
      a=rtpmap:8 PCMA/8000<br>
      a=rtpmap:101 telephone-event/8000<br>
      a=fmtp:101 0-16<br>
      a=silenceSupp:off - - - -<br>
      a=ptime:30<br>
      a=sendrecv<br>
      <br>
      What does all this mean?<br>
      <br>
      From the "A" leg of the call (which is placed by a LinkSys SPA922)
      I have:<br>
      <br>
&lt;sip_local_sdp_str&gt;v%3D0%0Ao%3DFreeSWITCH%201361974765%201361974767%20IN%20IP4%20176.58.88.201%0As%3DFreeSWITCH%0Ac%3DIN%20IP4%20176.58.88.201%0At%3D0%200%0Am%3Daudio%2011468%20RTP/AVP%208%20101%0Aa%3Drtpmap%3A8%20PCMA/8000%0Aa%3Drtpmap%3A101%20telephone-event/8000%0Aa%3Dfmtp%3A101%200-16%0Aa%3DsilenceSupp%3Aoff%20-%20-%20-%20-%0Aa%3Dptime%3A30%0Aa%3Dsendrecv%0A&lt;/sip_local_sdp_str&gt;<br>
      <br>
      From the troublesome "B" leg of the call (placed by FreeSwitch to
      my GXP2000) I have:<br>
      <br>
sip_local_sdp_str&gt;v%3D0%0Ao%3DFreeSWITCH%201361974745%201361974746%20IN%20IP4%20176.58.88.201%0As%3DFreeSWITCH%0Ac%3DIN%20IP4%20176.58.88.201%0At%3D0%200%0Am%3Daudio%2011488%20RTP/AVP%208%20101%2013%0Aa%3Drtpmap%3A101%20telephone-event/8000%0Aa%3Dfmtp%3A101%200-16%0Aa%3Dptime%3A30%0Aa%3Dsendrecv%0Am%3Daudio%2011488%20RTP/AVP%208%203%20101%2013%0Aa%3Drtpmap%3A101%20telephone-event/8000%0Aa%3Dfmtp%3A101%200-16%0Aa%3Dptime%3A20%0Aa%3Dsendrecv%0A&lt;/sip_local_sdp_str&gt;<br>
      <br>
      I was wondering if there's a way I can modify this to include
      a="silenceSupp:off - - - -" and whether that would make the
      slightest bit of difference to the handset's behaviour!<br>
      <br>
      <br>
      <br>
      Alex<br>
    </div>
    <blockquote cite="mid:512DE07F.3090503@digitalmail.com" type="cite">
      <meta content="text/html; charset=ISO-8859-1"
        http-equiv="Content-Type">
      <div class="moz-cite-prefix">Thanks.<br>
        I've been looking at the channel variables of the call. And this
        is part of it:<br>
        <br>
&lt;rtp_audio_in_raw_bytes&gt;1089091&lt;/rtp_audio_in_raw_bytes&gt;&lt;rtp_audio_in_media_bytes&gt;957212&lt;/rtp_audio_in_media_bytes&gt;&lt;rtp_audio_in_packet_count&gt;10344&lt;/rtp_audio_in_packet_count&gt;&lt;rtp_audio_in_media_packet_count&gt;5581&lt;/rtp_audio_in_media_packet_count&gt;&lt;rtp_audio_in_skip_packet_count&gt;5480&lt;/rtp_audio_in_skip_packet_count&gt;&lt;rtp_audio_in_jb_packet_count&gt;0&lt;/rtp_audio_in_jb_packet_count&gt;&lt;rtp_audio_in_dtmf_packet_count&gt;0&lt;/rtp_audio_in_dtmf_packet_count&gt;&lt;rtp_audio_in_cng_packet_count&gt;4323&lt;/rtp_audio_in_cng_packet_count&gt;&lt;rtp_audio_in_flush_packet_count&gt;440&lt;/rtp_audio_in_flush_packet_count&gt;&lt;rtp_audio_in_largest_jb_size&gt;0&lt;/rtp_audio_in_largest_jb_size&gt;&lt;rtp_audio_out_raw_bytes&gt;1829908&lt;/rtp_audio_out_raw_bytes&gt;&lt;rtp_audio_out_media_bytes&gt;1829908&lt;/rtp_audio_out_media_bytes&gt;&lt;rtp_audio_out_packet_count&gt;10639&lt;/rtp_audio_out_packet_count&gt;&lt;rtp_audio_out

_media_packet_count&gt;10639&lt;/rtp_audio_out_media_packet_count&gt;&lt;rtp_audio_out_skip_packet_count&gt;0&lt;/rtp_audio_out_skip_packet_count&gt;&lt;rtp_audio_out_dtmf_packet_count&gt;0&lt;/rtp_audio_out_dtmf_packet_count&gt;&lt;rtp_audio_out_cng_packet_count&gt;0&lt;/rtp_audio_out_cng_packet_count&gt;&lt;rtp_audio_rtcp_packet_count&gt;0&lt;/rtp_audio_rtcp_packet_count&gt;&lt;rtp_audio_rtcp_octet_count&gt;0&lt;/rtp_audio_rtcp_octet_count&gt;<br>
        <br>
        The thing that slightly concerns me here is
&lt;rtp_audio_in_cng_packet_count&gt;4323&lt;/rtp_audio_in_cng_packet_count&gt;<br>
        <br>
        That sounds as though the inbound audio path contains some
        comfort noise, suggesting that the handset the other end has
        some kind of silence suppression enabled.<br>
        <br>
        I'm afraid it's a dreaded Grandstream GXP2000 - which I know are
        not the handset of the cognoscenti! - but the customer tells me
        that he has silence suppression disabled. Do we think this is
        correct?!<br>
        <br>
        Rgds,<br>
        Alex<br>
      </div>
      <blockquote
cite="mid:CAKbxfG928nCmqEfGXeeNLA=q3wwpgFs72+7t4WwmxT3zbw+=KA@mail.gmail.com"
        type="cite">
        <div dir="ltr">It does not send any by default. &nbsp;Also, yes it
          only generates silence when the call is not getting any RTP.
          <div><br>
          </div>
        </div>
        <div class="gmail_extra"><br>
          <br>
          <div class="gmail_quote">On Tue, Feb 26, 2013 at 12:00 PM,
            Alex Lake <span dir="ltr">&lt;<a moz-do-not-send="true"
                href="mailto:alex@digitalmail.com" target="_blank">alex@digitalmail.com</a>&gt;</span>
            wrote:<br>
            <blockquote class="gmail_quote" style="margin:0 0 0
              .8ex;border-left:1px #ccc solid;padding-left:1ex">Does
              Freeswitch enable any kind of silence suppression by
              default? If I<br>
              have bridge_generate_comfort_noise=true, does that only
              have an effect<br>
              when the audio-generating end decides to stop sending RTP?<br>
              <br>
              Any other tips for diagnosing silence (it's kind of like a
              slow noise<br>
              gate effect)?<br>
              <br>
_________________________________________________________________________<br>
              Professional FreeSWITCH Consulting Services:<br>
              <a moz-do-not-send="true"
                href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a><br>
              <a moz-do-not-send="true"
                href="http://www.freeswitchsolutions.com"
                target="_blank">http://www.freeswitchsolutions.com</a><br>
              <br>
              FreeSWITCH-powered IP PBX: The CudaTel Communication
              Server<br>
              <a moz-do-not-send="true" href="http://www.cudatel.com"
                target="_blank">http://www.cudatel.com</a><br>
              <br>
              Official FreeSWITCH Sites<br>
              <a moz-do-not-send="true" href="http://www.freeswitch.org"
                target="_blank">http://www.freeswitch.org</a><br>
              <a moz-do-not-send="true"
                href="http://wiki.freeswitch.org" target="_blank">http://wiki.freeswitch.org</a><br>
              <a moz-do-not-send="true" href="http://www.cluecon.com"
                target="_blank">http://www.cluecon.com</a><br>
              <br>
              FreeSWITCH-users mailing list<br>
              <a moz-do-not-send="true"
                href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a><br>
              <a moz-do-not-send="true"
                href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users"
                target="_blank">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a><br>
              UNSUBSCRIBE:<a moz-do-not-send="true"
                href="http://lists.freeswitch.org/mailman/options/freeswitch-users"
                target="_blank">http://lists.freeswitch.org/mailman/options/freeswitch-users</a><br>
              <a moz-do-not-send="true" href="http://www.freeswitch.org"
                target="_blank">http://www.freeswitch.org</a><br>
            </blockquote>
          </div>
          <br>
          <br clear="all">
          <div><br>
          </div>
          -- <br>
          Anthony Minessale II<br>
          <br>
          FreeSWITCH <a moz-do-not-send="true"
            href="http://www.freeswitch.org/">http://www.freeswitch.org/</a><br>
          ClueCon <a moz-do-not-send="true"
            href="http://www.cluecon.com/">http://www.cluecon.com/</a><br>
          Twitter: <a moz-do-not-send="true"
            href="http://twitter.com/FreeSWITCH_wire">http://twitter.com/FreeSWITCH_wire</a><br>
          <br>
          AIM: anthm<br>
          <a moz-do-not-send="true"
            href="mailto:MSN%3Aanthony_minessale@hotmail.com">MSN:anthony_minessale@hotmail.com</a><br>
          GTALK/JABBER/<a moz-do-not-send="true"
            href="mailto:PAYPAL%3Aanthony.minessale@gmail.com">PAYPAL:anthony.minessale@gmail.com</a><br>
          IRC: <a moz-do-not-send="true" href="http://irc.freenode.net">irc.freenode.net</a>
          #freeswitch<br>
          <br>
          FreeSWITCH Developer Conference<br>
          <a moz-do-not-send="true"
            href="mailto:sip%3A888@conference.freeswitch.org">sip:888@conference.freeswitch.org</a><br>
          <a moz-do-not-send="true"
            href="mailto:googletalk%3Aconf%2B888@conference.freeswitch.org">googletalk:conf+888@conference.freeswitch.org</a><br>
          pstn:+19193869900 </div>
        <br>
        <fieldset class="mimeAttachmentHeader"></fieldset>
        <br>
        <pre wrap="">_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
<a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.freeswitchsolutions.com">http://www.freeswitchsolutions.com</a>

FreeSWITCH-powered IP PBX: The CudaTel Communication Server
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.cudatel.com">http://www.cudatel.com</a>

Official FreeSWITCH Sites
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.freeswitch.org">http://www.freeswitch.org</a>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://wiki.freeswitch.org">http://wiki.freeswitch.org</a>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.cluecon.com">http://www.cluecon.com</a>

FreeSWITCH-users mailing list
<a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a>
UNSUBSCRIBE:<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://lists.freeswitch.org/mailman/options/freeswitch-users">http://lists.freeswitch.org/mailman/options/freeswitch-users</a>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.freeswitch.org">http://www.freeswitch.org</a>
</pre>
        <br>
        <fieldset class="mimeAttachmentHeader"></fieldset>
        <br>
        <p class="" avgcert""="" color="#000000" align="left">No virus
          found in this message.<br>
          Checked by AVG - <a moz-do-not-send="true"
            href="http://www.avg.com">www.avg.com</a><br>
          Version: 2012.0.2238 / Virus Database: 2641/5634 - Release
          Date: 02/26/13</p>
      </blockquote>
      <br>
      <br>
      <fieldset class="mimeAttachmentHeader"></fieldset>
      <br>
      <pre wrap="">_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
<a class="moz-txt-link-abbreviated" href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a>
<a class="moz-txt-link-freetext" href="http://www.freeswitchsolutions.com">http://www.freeswitchsolutions.com</a>

FreeSWITCH-powered IP PBX: The CudaTel Communication Server
<a class="moz-txt-link-freetext" href="http://www.cudatel.com">http://www.cudatel.com</a>

Official FreeSWITCH Sites
<a class="moz-txt-link-freetext" href="http://www.freeswitch.org">http://www.freeswitch.org</a>
<a class="moz-txt-link-freetext" href="http://wiki.freeswitch.org">http://wiki.freeswitch.org</a>
<a class="moz-txt-link-freetext" href="http://www.cluecon.com">http://www.cluecon.com</a>

FreeSWITCH-users mailing list
<a class="moz-txt-link-abbreviated" href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a>
<a class="moz-txt-link-freetext" href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a>
UNSUBSCRIBE:<a class="moz-txt-link-freetext" href="http://lists.freeswitch.org/mailman/options/freeswitch-users">http://lists.freeswitch.org/mailman/options/freeswitch-users</a>
<a class="moz-txt-link-freetext" href="http://www.freeswitch.org">http://www.freeswitch.org</a>
</pre>
      <br>
      <fieldset class="mimeAttachmentHeader"></fieldset>
      <br>
      <p class="" avgcert""="" color="#000000" align="left">No virus
        found in this message.<br>
        Checked by AVG - <a moz-do-not-send="true"
          href="http://www.avg.com">www.avg.com</a><br>
        Version: 2012.0.2238 / Virus Database: 2641/5635 - Release Date:
        02/26/13</p>
    </blockquote>
    <br>
  </body>
</html>