<br><br><div class="gmail_quote">On Wed, Apr 6, 2011 at 2:15 PM, Mark Sobkow <span dir="ltr"><<a href="mailto:m.sobkow@marketelsystems.com" target="_blank">m.sobkow@marketelsystems.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
We've tried several different softphones: Phoner (SIPPER stack), X-Lite,<br>
and our internal M-Phone (I forget what SIP stack implementation that<br>
uses, as I didn't write it.) All exhibit the same problem.<br>
<br>
Our network admin insists it's not a network problem. As we hadn't had<br>
this problem previously, I can't argue with him over it.<br>
<br>
I'm a little unclear about what is supposed to be sending the ACK -- the<br>
softphone, FreeSwitch, or our application code.<br></blockquote><div><br></div><div>This is typical SIP traffic, so the UA sending the INVITE should be ACKing the appropriate responses from FS. In your case, FreeSWITCH sends a 200 OK several times, indicating that the phone has answered the INVITE. However, FS is not receiving the required ACK from the UA so it gives up and sends a BYE.</div>
<div><br></div><div>So, what Tony said is correct - for *some* reason the ACK is not making it back to FreeSWITCH. This is *not* a problem with FreeSWITCH, it's a problem on the network or with the originating UA. </div>
<div><br></div><div>Are you able to confirm that the UA is seeing the 200 OK from FreeSWITCH? That sounds like a reasonable first place to troubleshoot.</div><div><br></div><div>-MC</div></div>