Stuff

this will go for all international calls need to block these on one outgoing line
001
019
02
002
013
021
018
008
1521
1511
1900

and allow other numbers not starting with any of these code prefixes

exten => _900[128].,1,Congestion
exten => _901[938].,1,Congestion
exten => _902.,1,Congestion
exten => _915[12]1.,1,Congestion
exten => _91900.,1,Congestion