There is a common confusion between SIM unlocking via code and firmware unlocking . For the B311221, they are intertwined.
Unlocking allows you to use the router with any network provider worldwide. huawei router b311221 unlock firmware
Unlocking the router is typically done through a network unlock code rather than a firmware flash, as modifying firmware can risk permanently "bricking" the device. While some modified firmware files exist in enthusiast communities, official and secure methods rely on the device's built-in SIMLOCK interface. Primary Unlocking Method (IMEI Code) There is a common confusion between SIM unlocking