В черное окно добавьте следующий фрагмент кода:
[all-outgoing-custom]
exten => _[0-9*#+a-zA-Z][0-9*#+a-zA-Z]!,1,NoOp(-)
same => n,NoOp("${PROVIDER_ID}" --- "${ONLY_THIS_PROVIDER}")
same => n,Set(NEED_RETURN=${UNDEFINED})
same => n,ExecIf($["${ONLY_THIS_PROVIDER}x" == "x"]?return)
same => n,ExecIf($["${PROVIDER_ID}" != "${ONLY_THIS_PROVIDER}"]?Set(NEED_RETURN=1))
same => n,ExecIf($["${PROVIDER_ID}" != "${ONLY_THIS_PROVIDER}"]?Set(ROUTFOUND=${UNDEFINED}))
same => n,Return()
[add-trim-prefix-clid-custom]
exten => _[0-9*#+a-zA-Z][0-9*#+a-zA-Z]!,1,NoOp(start check blacklist)
same => n,ExecIf($["${CHANNEL(channeltype)}" == "PJSIP" ]?Set(__ONLY_THIS_PROVIDER=${CHANNEL(endpoint)}))
same => n,Return()