A400P don't dial out

I did some tests and discovered the following:

if I dial for example: 98095930739 and Wait 1 second between each digit the call progrest perfectly. but if i dial the numer faster the call dont progrest.

you have idea of the problem?

helllo:
I think you have to try to set dfferent dtmf options for your account and see what is a good result. you can set that frm GUI of your SIP phone. i think it is one of the reasons why the problem occurs.
regards!
James.zhu