Our telco recently changed their call progress tones:

Dialtone: 450Hz continuous

Ringback tone: 450Hz/1 sec ON 4 sec OFF

Busy tone:  450Hz/360ms ON 360 OFF

Attn: 950Hz/continuous (0db)

The way I understand it, FXO listens for the dialtone then sends DTMF tones. After this, it expects either the Ringback or Busy tone. I read Michael Collin's post that FreeTDM doesn't detect (as of now) cadence.  http://permalink.gmane.org/gmane.comp.telephony.freeswitch.user/36531

Questions:

1. What state will FreeTDM go when it detects 450Hz? Ringing or Busy? I presume it would be Ringing or it would hangup.

2. Can I use tone_detect to distinguish them?  Can I use a series of tone_detects? Any suggestion where to go?

If not ...

My last recourse will be - wait for the Attn tone. But ... will FreeTDM jump to hangup the call upon detecting this?

Thanks,

/Nandy