orangelau,
Is this a problem where you dial an outgoing call, then you do not hear a ringing tone for 10 seconds, then you hear ringing tone and the call connects normally?
If this is so, then it will be a digit map problem. This is the default PSTN Line Port DigitMap:
Physical Interfaces > LINE Port > DigitMap:
(xxxxxxxS4|1xxxxxxxxxx|xx.)
I know that you do not live in North America, so this digit map may not be right for you. If the number you dial is not matched by any other rule, then the rule "xx." will be used. "xx." waits for 10 seconds after you dial the last digit to see if you have finished dialling, then sends the number out to the PSTN line.
If this is the problem, then please give more details of the number formats that you dial using the PSTN line. If this is not the problem, then please give more details - is it an incoming PSTN call problem or an outgoing PSTN call problem etc.