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.
Access the management page (usually 192.168.8.1 ). A prompt for a "SIMLOCK Code" or "NCK" should appear. Enter your code and click Apply . Method 2: Firmware Upgrade/Flash B311-221 Unlock Firmware
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 Unlock firmware is a modified or official software
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. A prompt for a "SIMLOCK Code" or "NCK" should appear