Have posted a few times with my experience with this. my scenario was that calls would disconnect with time ranging from 13 secs to sometimes never.
had to create a voice class with tones specific values : cadence busy etc and also ask the provider to put the lines into a trunk group. purpose of this is to enable COD on their side.
this is what it looks like
voice class dualtone-detect-params 100
freq-max-deviation 50
freq-min-power 35
!
voice class custom-cptone TEST
dualtone busy
dualtone ringback
frequency 500 632
dualtone reorder
frequency 500 631
cadence 500 500
dualtone disconnect
frequency 630
cadence 500 500
and on the voice port
voice-port 0/0/0
supervisory disconnect dualtone mid-call
supervisory custom-cptone TEST
supervisory dualtone-detect-params 100
no battery-reversal
timeouts initial 4
timeouts interdigit 2
timeouts call-disconnect 0
connection plar 139
your values will probably not be the same. Also this by itself didnt work for me, i had to apply this as well as ensure the lines were in a trunk group with COD enabled.
P.S converting lines to Ground Start is also another solution.
