[Asterisk-Users] X100P and DTMF sending

[Tim Robinson]

Hi -
I have a problem with DTMF dialling when in conjunction with a 
Grandstream SIP phone.

Problem:  My SIP phone is set to 'early send' (coz I don't like waiting 
too long after dialling!)...

I want to dial a long series of DTMF carrier access digits before the 
digits dialled from the phone itself.  i.e. 1411877xxxxxxx where xxxxxxx 
is the number I want to dial.

My dial string looks like this:

exten => _901.,1,Dial(${TRUNK}/1411877${EXTEN:1})
exten => _901.,2,Congestion

Listening via a hi-z monitor I hear the digits 1411877012 going to line, 
and then things start to go wrong, as Asterisk does not seem to 
correctly buffer digits being dialled.  This means that unless I wait 
for the bulk of the digits to get sent, Asterisk loses track of where it 
is, and I lose a bunch of digits completely.

In contrast, overlap sending (which is in effect what I am doing) works 
fine on my E1 PRI.

Any suggestions please?

Rgds
Tim