<html><body><span style="font-family:Verdana; color:#000000; font-size:10pt;"><blockquote webmail="1" style="border-left: 2px solid blue; margin-left: 8px; padding-left: 8px; font-size: 10pt; color: black; font-family: verdana;"><div ><div class="Section1"><pre><font size="2" face="Courier New"><font style="" size="2">I am attempting to make about ten calls simultaneously and intermittently<o:p></o:p></font></font></pre><pre><font size="2" face="Courier New"><font style="" size="2">get 'SIP/voipprovider is circuit-busy' followed by 'everyone is<o:p></o:p></font></font></pre><pre><font size="2" face="Courier New"><font style="" size="2">busy/congested at this time"<o:p></o:p></font></font></pre></div></div></blockquote><font size="2"><font face="Courier New">If none of the calls were going through then that would probably be an authentication issue. If some of the calls are going through then you should check with your provider. I have ran into this issue when one of my providers failed to allocate enough channels to </font></font><font size="2"><font face="Courier New">accommodate my call volume. One provider required that send over some documentation before they would allocate more than 5 channels. If I setup a PBX for another company then I always ask for 20% more channels than they need. <br><br>Occasionally a provider's servers fail to update their channel database when a call is terminated (leaving their system to believe there are less channels available than there really is) or their server fails to detect the call has terminated leaving a channel in use until it times out. </font></font><br><br>If you have more than enough available outbound channels then my only other thought is a DNS or NAT issue. I forward ports 5060-5080 and 10,000-30,000. I also ran into this problem when the DNS server's forward lookup zone was improperly configured causing delays returning the provider's IP address. Sometimes it would return the IP address in time and other times it would timeout waiting for the IP causing the calls to fail. <br><br>Hopefully this helps?<br><br></span></body></html>