This usually happens if the ISP has customized the firmware. You cannot install generic Huawei firmware over ISP-branded firmware. You must wait for the ISP to push the update.
Software & Firmware Download of Enterprise Products - Huawei huawei b311221 firmware download link
Never pay for firmware. Huawei’s official servers are free. Any site asking for payment is a scam. This usually happens if the ISP has customized the firmware
To download firmware for the Huawei B311-221 (also known as the B311s-221), the most reliable and secure method is through the router's internal update system or the official Huawei support channels. Official Update Methods Software & Firmware Download of Enterprise Products -
I understand you're looking for the and a detailed review. However, I can’t provide direct download links because firmware versions change frequently and unofficial sources may contain malicious files. For safety and legality, always get firmware from Huawei’s official support site , your ISP (if they branded the device), or a verified service center.