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--></style></head><body lang="EN-US" link="#0563C1" vlink="#954F72"><div class="WordSection1"><p class="MsoNormal">Let’s say I have 3 SIP endpoints: Caller_A, Caller_B and Caller_C</p><p class="MsoNormal"> </p><p class="MsoNormal">Initially Caller_A calls Caller_B, so we end up with a SIP call between them.</p><p class="MsoNormal"> </p><p class="MsoNormal">But now, there will be some cases, when Caller_A will want to ‘conference in’ Caller_C into the call between Caller_A and Caller_B.</p><p class="MsoNormal"> </p><p class="MsoNormal">How is it normally done? Based on my limited understanding of mod_conference, I would attempt doing it as following:</p><p class="MsoNormal"> </p><p class="MsoNormal">Approach I: </p><p class="MsoNormal">Tear down the original call between A & B, and set up a conference between A, B & C:</p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l1 level1 lfo1"><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman""> </span></span>Caller_A calls Caller_B</p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l1 level1 lfo1"><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman""> </span></span>SIP call is established between Caller_A and Caller_B.</p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l1 level1 lfo1"><span style="mso-list:Ignore">3.<span style="font:7.0pt "Times New Roman""> </span></span>After a while Caller_A wants to conference in Caller_C, as following:</p><p class="MsoListParagraph" style="margin-left:1.0in"><span style="mso-list:Ignore">a.<span style="font:7.0pt "Times New Roman""> </span></span>Caller_A hangs up the call with Caller_B</p><p class="MsoListParagraph" style="margin-left:1.0in"><span style="mso-list:Ignore">b.<span style="font:7.0pt "Times New Roman""> </span></span>Caller_A dials into a conference room.</p><p class="MsoListParagraph" style="margin-left:1.0in"><span style="mso-list:Ignore">c.<span style="font:7.0pt "Times New Roman""> </span></span>Caller_B dials into the same conference room.</p><p class="MsoListParagraph" style="margin-left:1.0in"><span style="mso-list:Ignore">d.<span style="font:7.0pt "Times New Roman""> </span></span>Caller_C dials into the same conference room.</p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l1 level1 lfo1"><span style="mso-list:Ignore">4.<span style="font:7.0pt "Times New Roman""> </span></span>Caller_A, Caller_B and Caller_C are now in a conference.</p><p class="MsoNormal"> </p><p class="MsoNormal">Approach II: </p><p class="MsoNormal">Use conferences for all calls from the beginning, even the 2-way calls, to make it easier to conference in additional callers:</p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><span style="mso-list:Ignore">1.<span style="font:7.0pt "Times New Roman""> </span></span>Caller_A dials into a conference room.</p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><span style="mso-list:Ignore">2.<span style="font:7.0pt "Times New Roman""> </span></span>Caller_B dials into a conference room.</p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><span style="mso-list:Ignore">3.<span style="font:7.0pt "Times New Roman""> </span></span>Calelr_A and Caller_B can now talk to each other.</p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><span style="mso-list:Ignore">4.<span style="font:7.0pt "Times New Roman""> </span></span>After a while Caller_A wants to conference in Caller_C</p><p class="MsoListParagraph" style="margin-left:1.0in"><span style="mso-list:Ignore">a.<span style="font:7.0pt "Times New Roman""> </span></span>Caller_C dials into the same conference room.</p><p class="MsoListParagraph" style="text-indent:-.25in;mso-list:l0 level1 lfo2"><span style="mso-list:Ignore">5.<span style="font:7.0pt "Times New Roman""> </span></span>Caller_A, Caller_B and Caller_C are now in a conference.</p><p class="MsoNormal"> </p><p class="MsoNormal"> </p><p class="MsoNormal">I’ve also read about eavesdrop tool, but I understand it only allows 3-way communication, and I need to be able to support N-way.</p><p class="MsoNormal"> </p><p class="MsoNormal">Thanks.</p></div></body></html>