Update your modem settings.
Update your modem settings.
Consider upgrading to a better modem for improved range and security. Since anyone can adjust your Wi-Fi settings, it’s wise to replace your current device. The BSNL fiber connection you have works well, but their advice suggests switching to an ONU modem. While browsing online, you’ll find many ONU models—some offer Wi-Fi, others don’t. You might want to choose a model with built-in Wi-Fi or pair it with a separate router for full functionality.
Suggest using a wired connection instead of Wi-Fi and invest in a robust router with strong security options. Remember to include a reliable Ethernet cable such as Cat 7, particularly if you're aiming for Wi-Fi 6. My setup came with a modem that had Wi-Fi, but I ended up disabling its wireless mode and switching to the Asus router instead. It offers solid features like bandwidth control, blocked intranet access, guest accounts, and mesh networking if you add another router supporting the same system. I'm satisfied with the coverage and capabilities given its affordable price. You mentioned living in another country, but the issue remains similar—your ISP provides a weak modem with limited range and poor security. It's a budget Huawei model.
Cat 5e works well for Gigabit and brief-distance high-speed connections. Cat 7 is not recommended under any circumstances—it's considered unofficial. For maximum performance, stick to Cat 6a; it's better than nothing if you're using Gigabit or lower speeds.
For Fiber equipment, there are very limited choices available. It seems you're dealing with a gateway device, combining a fiber media converter and a router. AT&T in the US operates similarly—customers cannot upgrade their existing boxes, and these units lack true bridge functionality. They do provide a pass-through mode, but it performs poorly based on my understanding. My recommendation would be to retain your current ISP box and ask them to enable bridge mode. This will disable the router portion of the device. After that, you can purchase a router that meets your requirements.