I'm implementing a simple calling card feature for testing purpose. I have a DID number, when I called my DID number and enter the phone number to call, Asterisk would dial the number for me but the sound was only one way.<div>
<br></div><div>After hours of struggling with the problem, I found out that I need to add "t" to my dial options, this is the correct way of dialing out:</div><div><br></div><div> -> Dial(SIP/carrier/3105555555|20|t)</div>
<div><br></div><div>Now I need to know what was going on? Why with option "t" both parties can hear each other, but without option "t" in dial cmd only one party could hear?</div><div><br></div><div>Another interesting issue is, if I use Answer() command at the begining the sound becomes one way even if I use "t" in options.</div>
<div><br></div><div><br></div><div>One more interesting thing, my carrier for calling out only accepts G7.29 where as my DID provider passes calls as ulaw. However, when using <a href="http://voipjet.com">voipjet.com</a> (as secondary carrier) which carries out the calls as ulaw, having the Dial cmd without "t" option works fine.</div>
<div><br></div><div><div>I'd appreciate if someone explain to me the following questions:</div><div> 1) Why when there is codec difference, Dial cmd needs the "t" option</div><div> 2) Why using Answer cmd causes problem in this case (all the cases, when using same codec and also different codecs)</div>
<div> 3) Why with same codecs, Dial cmd does not need "t" option?</div><div><br></div><div>Thanks</div><div><br></div><div>Moe</div></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div>