se debe colocar igual en extensions_custom
[from-trunk-sip-CLARO_CELULAR]
include => from-trunk-sip-CLARO_CELULAR-custom
exten => .,1,Set(GROUP()=OUT_2)
;le coloque 70 para que le queden libres 10
exten => X.,n,GotoIf($[${GROUP_COUNT(OUT_2)} < 70]?continue:hang)
exten => .,n(continue),Goto(from-trunk,${EXTEN},1)
exten => X.,n(hang),Hangup
atentamente,