S20 with 8 extensions, 2 sip trunk and 2 FXO ports.
ONLY when i try to call holland numbers (prefix: 0031) the call fail.
Is not sip trunk problem, i've tried with direct connection to sip trunk with success.
In the system log i see that tha call is failed, but i don't understand the reason.
All other international calls works good.
I can't call only holland numbers! STRANGE?
What can i do??