Asterisk Number Matching regular expressions how to block everything except Russian?

Question

Telephony

They get a phone from all over the world, how to block at least all non-Russians?

Answer 1

set them on Function_REGEX

exten => _X.,1,NoOp()
    same => n,GotoIf($[${REGEX("^[+]?[78][0-9]{10}$" ${CALLERID(num)})}]?rf)
    same => n,Answer(1) ; сюда попадет весь левак
    same => n,PlayBack(tt-monkeys)
    same => n,Hangup() ; ложим трубку
    same => n(rf),NoOp(Work) ; это свои. идем дальше по диалплану
....