You cannot download a random firmware file. If you flash the wrong version, your router will become a brick (permanently unusable). Follow this checklist:
A: No. The N300 is hardware-limited to 300Mbps on the local network and typically ~100Mbps WAN-to-LAN. Firmware cannot bypass hardware limits. tenda wireless n300 router firmware update updated
A: Yes, but only if Tenda allows it. Many new builds disable downgrading for security reasons. Use the same method (upload the older .bin file). You cannot download a random firmware file
Remember: An outdated router is a security risk. A correctly updated router is a reliable gateway to the digital world. tenda wireless n300 router firmware update updated