Callmanager and Asterisk without MTP?

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Mar 15th, 2007
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we are using Cisco Callmanager (at the moment 4.1(3)) with Asterisk (1.2.4) through SIP-Trunk. Everything works fine. There are several bugs regarding locked MTP-ressources (solved with ES93).

Because of the bugs and of centralized call-distribution we would like to avoid MTP at all.

Any one who has successfully avoid MTP (as far as I know only for DTMF) with SIP(-Trunks)?

Any solution with any SW-version welcome.

Thanks in advance


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s.jankowski Wed, 03/21/2007 - 08:08
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I have tried without MTP in SIP trunks.If you are trunking against another CallManager or Cisco voice gateway, you

don't need a MTP since the other side supports the supplementary features already

schemberg Wed, 03/21/2007 - 08:40
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Thank you for your reply,

only new phones (79x1) support RFC2833 DTMF, so CM 5.x and above uses MTP "dynamically" if it detects, that the phone (only outofband DTMF) and asterisk (RFC, inband, ...) don't support the same DTMF mode.

kind regards



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