mentax: I don't think so. I beleive it's possible to have duplicate MACs on the system, so long as they are in different accounts.

ruhnet: Kazoo check if the mac address is existed on the system, if it is it returned an error that this mac already in use and can't be add

mentax: According to this code, it is looking if the given MAC address is already in use within the account you are trying to add the device to or if it is already in use in the provisioner server. github.com/2600hz/kazoo/blob/4.3.14…ules_v2/cb_devices_v2.erl#L650-L651

If it is not in use in the account, and the check is still failing, it means "provisioner_v5" is being used. In such case, you can issue the following SUP command to know which account is using that MAC address for provisioning: sup provisioner_v5 check_MAC "MAC_ADDRESS" "{AUTH_TOKEN}"

I have not tested that command myself. I just came up with it based on this function's implementation github.com/2600hz/kazoo/blob/4.3.14…c/modules/provisioner_util.erl#L325

doesn't work =(

Did you replace the {MAC_ADDRESS} and the {AUTH_TOKEN} with valid values on the command?