<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:courier,monaco,monospace,sans-serif;font-size:12pt">You have a few options:<br><br>Early Negotiation (default behaviour):<br><br>*) When leg A calls FS the codecs will be compared against the <br> configured codecs in the profile config.<br>*) When B sends the invite, the chosen codec in leg A will be pushed to<br> the top of the list regardless of if it's actually chosen in the config.<br> (the other codecs offered to leg A will not appear)<br><br>Late Negotation (requires param):<br><param name="inbound-late-negotiation" value="true"/><br><br>*) The call will hit the dialplan without looking at the codecs at all.<br>*) The negotiation will take place when leg A is answered.<br>*) This allows you to route the call to a script and examine the sdp<br> and rewrite the acceptable codecs with the "codec_string" channel
variable.<br><br>Early Negotiation + Disable Transcoding:<br><param name="disable-transcoding" value="true"/><br>If this sofia profile param is set, all B legs that you invite will<br>contain *only* the codec negotiated by the A leg.<br><br><br>Also in either case the variable "codec_string" on the A leg controls<br>what codecs will be offered to the B leg.<br><br>The variable "absolute_codec_string" is similar except it implies the implicit list of codecs and will disable the addition of the A leg codec to the list<br>as described in the defualt behaviour.<br><br><br><br><br><div> </div><div>Anthony Minessale II<br><br><span>FreeSWITCH <a target="_blank" href="http://www.freeswitch.org/">http://www.freeswitch.org/</a></span><br><span>ClueCon <a target="_blank" href="http://www.cluecon.com/">http://www.cluecon.com/</a></span><br><br>AIM: anthm<br>MSN:anthony_minessale@hotmail.com<br>JABBER:anthony.minessale@gmail.com<br>IRC: irc.freenode.net
#freeswitch</div><div><br>FreeSWITCH Developer Conference<br>sip:888@conference.freeswitch.org<br>iax:guest@conference.freeswitch.org/888<br>googletalk:conf+888@conference.freeswitch.org<br>pstn:213-799-1400</div><div style="font-family: courier,monaco,monospace,sans-serif; font-size: 12pt;"><br><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;">----- Original Message ----<br>From: James H Thompson <jht@lj.net><br>To: freeswitch-users@lists.freeswitch.org<br>Sent: Monday, April 2, 2007 6:20:50 PM<br>Subject: [Freeswitch-users] Codec negotiation<br><br>
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<div><font face="Arial" size="2">I wondering how FreeSwitch does codec negotiation
in the following call flow:</font></div>
<div> </div>
<div><font face="Arial" size="2"> SIP Endpoint A ---->
FreeSwitch ----> SIP Endpoint B</font></div>
<div> </div>
<div><font face="Arial" size="2">For example, if the SIP Endpoint A offers Codecs:
G.711u, G.711a, G.729<br>when FreeSwitch sets up the Call to SIP Endpoint B, how
does it determine<br>what list of Codecs to offer to SIP Endpoint
B?</font></div>
<div> </div>
<div><font face="Arial" size="2">What I'm looking for is for Freeswitch to always
offer the same list of<br>Codecs to SIP Endpoint B as it received from SIP
Endpoint A.</font></div>
<div> </div>
<div><font face="Arial" size="2">In this application, having the RTP packets bypass
FreeSwitch and<br>go directly between SIP Endpoint A and SIP Endpoint B is not
an option<br>since the two SIP Endpoints cannot talk to each other
directly.<br>SIP Endpoint A is in public IP space, and SIP Endpoint B is in
private IP<br>space.<br></font></div><div>_______________________________________________<br>Freeswitch-users mailing list<br>Freeswitch-users@lists.freeswitch.org<br><a target="_blank" href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a><br>UNSUBSCRIBE:<a target="_blank" href="http://lists.freeswitch.org/mailman/options/freeswitch-users">http://lists.freeswitch.org/mailman/options/freeswitch-users</a><br><a target="_blank" href="http://www.freeswitch.org">http://www.freeswitch.org</a><br></div></div><br></div></div><br>
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