How to Upgrade the firmware version of TP-Link Wireless Router
TP-Link N600 Wireless Dual Band Gigabit Router Model TL-WDR3600 version 1.5 | eBay
Amazon.com: TP-Link N300 Wireless Extender, Wi-Fi Router (TL-WR841N) - 2 x 5dBi High Power Antennas, Supports Access Point, WISP, Up to 300Mbps : Electronics