Disconnect the DSL or WAN cable from the back of the router so it is completely offline.
Change the 2.4 GHz channel width from . While 40 MHz promises higher theoretical speeds, it is highly susceptible to interference in crowded neighborhoods. A 20 MHz width provides a much cleaner, more stable signal. sagemcom fast 4315 firmware extra quality
If your ISP requires a manual update, you must first download the specific firmware file from your provider's official support page. Navigate to Maintenance > Firmware Update . Disconnect the DSL or WAN cable from the