Leave it on the ISP firmware it came with, let it auto-update over the air, and never manually flash a file from a forum. If you need advanced features (band locking, TTL mangling, VPN integration), sell the B311-221 and buy a ZTE MC801A or a GL.iNet router instead.
Flashing generic firmware (e.g., the Russian or European unbranded version) removes the ISP lock and APN, but it often on specific networks. Furthermore, you cannot revert to ISP firmware without a full backup of the original flash partitions—something 99% of users do not have. huawei b311-221 firmware download
If you own a Huawei B311-221 4G LTE router, you have likely encountered a frustrating reality: finding official firmware is like hunting for a ghost. Leave it on the ISP firmware it came
Have you successfully flashed a B311-221? What region and firmware version are you running? Let us know in the comments—but please, no direct download links to unverified files. Furthermore, you cannot revert to ISP firmware without
Backup your current firmware first using dd commands via telnet (requires enabling developer mode), and only flash files signed by your original ISP.