Unlocking your router via firmware or an unlock code can save you from high roaming charges and provide the freedom to switch to the best local data plans.
If your router’s current firmware has hidden the unlock menu, you may need to flash a general version. Huawei B311-221 Firmware Release Notes | PDF - Scribd B311-221 Unlock Firmware
Unlock firmware is a modified or official software version that removes the SIM lock restriction. In many cases, you may only need to update to a "General" or "Global" firmware version to enable the SIM lock menu, where you can then enter a unique 15-digit IMEI-based unlock code. Unlocking your router via firmware or an unlock
Often used to fix stability issues and is a common target for those looking for "clean" firmware. In many cases, you may only need to
Use a trusted third-party service like DirectUnlocks or ExpressUnlocks to generate a code based on your IMEI.