[Asterisk-Users] DTMF recognition inconsistent in Asterisk

[Monty]

Hello,

I am experiencing a strange problem and I am wondering if anyone may have 
some pointers as to how to overcome it.

I have an account with VoipTalk here in the UK which I have connected to 
my Asterisk server.  VoipTalk supports IAX2 and SIP and I have connected 
to my Asterisk box using both methods.  The problem is when I dial into my 
Asterisk box via my VoipTalk incoming PSTN phone number from a landline or 
mobile Asterisk does not consistently recognise DTMF's.

I have my VoipTalk context for incoming calls set to dial an extension in 
my house then forward on no-answer to Asterisk voicemail.  The idea is to:

--go into the voicemail box
--go to administrative options
--place an outgoing call
--dial a local extension that activates the DISA function
--Once in DISA, enter a DISA password and then it's possible to dial any 
other locally defined extension.

When I hear my voicemail greeting I press star to get to the prompt where 
I can enter my voicemail password.  Asterisk seams to consistently 
recognise both the star and my password.  So far, so good!

Then, I press "4" for administrative options and "3" for place an outgoing 
call.  Again this works fine.

The problem however is when I attempt to dial the extension assigned to my 
DISA function.  More often than not, Asterisk seams to miss my DTMF's.  In 
the event I do get to my DISA password prompt, it more often than not 
misses DTMF's there as well.

I have this same problem no matter if I use IAX or SIP to connect to 
VoipTalk.  When connected via SIP I have the DTMF signalling set to 
"inband" which seams to work as I am able to get into my voicemail box as 
I said above.

Can anyone offer a suggestion as to why it seams like Asterisk is 
inconsistent with recognising DTMF's?  Does it use different recognition 
routines in different function s of the programme?  Is there a way to 
heighten the recognition sensitivity?


Any ideas would be very much appreciated!

Thanks in advance
   Monty