do you have SW and/or HW conference resources ?<br><br>if you don't have HW resources you won't be able to create a conference call. If i remember correctly the codec on SIP trunks is G.729, you will need a transcoder or you can try with a SW MTP.<br>
<br>I had a similar problem, but my call was going to a CUBE gateway. on the trace i was seeing MTP errors<br><br>I configured a Software MTP resource and my problems went away<br><br><div class="gmail_quote">2010/4/7 Peter Slow <span dir="ltr"><<a href="mailto:peter.slow@gmail.com">peter.slow@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">are there any odd-looking messages in your callmanager event log?<br>
Saying things abotu media resource lists?<br>
<div><div></div><div class="h5"><br>
On Wed, Apr 7, 2010 at 1:10 PM, cisco.voip <<a href="mailto:cisco.voip@verizon.net">cisco.voip@verizon.net</a>> wrote:<br>
> All, need help -<br>
> I am Sending and Receiving call from my skinny cucm phones to the sip<br>
> provider fine.<br>
> However, when connected cucm phone -to- sip trunk phone,<br>
> when I try to conference on the cucm phone, conf button will not take<br>
> affect.<br>
> then i hang up and it says 'invalid conference participant'.<br>
><br>
><br>
> Thanks<br>
><br>
><br>
> _______________________________________________<br>
> cisco-voip mailing list<br>
> <a href="mailto:cisco-voip@puck.nether.net">cisco-voip@puck.nether.net</a><br>
> <a href="https://puck.nether.net/mailman/listinfo/cisco-voip" target="_blank">https://puck.nether.net/mailman/listinfo/cisco-voip</a><br>
><br>
<br>
_______________________________________________<br>
cisco-voip mailing list<br>
<a href="mailto:cisco-voip@puck.nether.net">cisco-voip@puck.nether.net</a><br>
<a href="https://puck.nether.net/mailman/listinfo/cisco-voip" target="_blank">https://puck.nether.net/mailman/listinfo/cisco-voip</a><br>
</div></div></blockquote></div><br>