<br><br><div class="gmail_quote">On Tue, Oct 16, 2012 at 1:31 PM, Richard Kenner <span dir="ltr"><<a href="mailto:kenner@gnat.com" target="_blank">kenner@gnat.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
We recently set up a SIP trunk between an office in NY running Asterisk and<br>
an office in Paris (running Alcatel). All works fine if a SIP phone on the<br>
NY system talks to the Paris PBX. But if something on DAHDI (a PRI or<br>
MeetMe) talks to the Paris PBX, there's a low-volume crackling. This isn't<br>
clipping because it also occurs when there's no legitimate sound. It's<br>
sort of a mild version of what you used to get when a POTS pair had a<br>
ground short. This occurs no matter what size originates the call.<br>
<br>
pings show round trip times of around 100ms, ranging from around 200 to 80<br>
ms. Packet loss is zero. The fact that SIP->SIP works fine suggests the<br>
issue isn't related to IP issues.<br>
<br>
I tried adding a jitter buffer, but that didn't make a difference.<br>
<br>
I've tried this sending just ULAW and G722 and allowing everything, but no<br>
difference. The SDP that comes back from Paris doesn't list any audio<br>
codecs and is:<br>
<br>
v=0<br>
o=default 1350406175 1350406175 IN IP4 10.10.22.246<br>
s=Asterisk PBX 10.7.1<br>
c=IN IP4 10.10.22.246<br>
t=0 0<br>
m=audio 32000 RTP/AVP 0 101<br>
a=sendrecv<br>
a=rtpmap:101 telephone-event/8000<br>
a=fmtp:101 0-15<br>
a=ptime:20<br>
a=maxptime:90<br>
m=video 0 RTP/AVP 31 34 34 98 99 104<br>
a=rtpmap:31 H261/90000<br>
a=rtpmap:34 H263/90000<br>
a=rtpmap:34 H263/90000<br>
a=rtpmap:98 h263-1998/90000<br>
a=rtpmap:99 H264/90000<br>
a=rtpmap:104 MP4V-ES/90000<br>
a=sendrecv<br>
<br>
Does anybody have any ideas as to what I should look at next?<br>
<br></blockquote><div><br></div><div>cat proc/interrupts?</div><div><br></div><div> <a href="http://wiki.openvox.cn/index.php/Troubleshooting_of_PRI_cards">http://wiki.openvox.cn/index.php/Troubleshooting_of_PRI_cards</a></div>
<div><br></div><div>Thanks,</div><div>Steve T</div></div>