Warning: Firmware for the older HG8245H or HG8245W (non-5) is NOT compatible with the W5.

Firmware must match hardware revision exactly. Never cross-flash between HG8245H, HG8245W, or HG8245W5-6T.

Most users encounter the HG8245W5 because it is a staple Optical Network Terminal (ONT) provided by ISPs for fiber-to-the-home connections. For many, it's a "black box" where the ISP has disabled nearly all advanced settings.