Model of your range extender? Firmware is up to date? How about stability of wired connection to the extender? Have you connected to the main router wirelessly and test for some time?

Airport express? Provide a simple topology pls. Did you try wired connection to WA850RE? When connection drops, lights are still normal? How did you make it work again?

What's the model number pls? If it is a wireless router instead of wireless modem router, it has no ADSL light and it has to work with another modem... Sorry but I'm confused what you said...

I'm afraid not... Maybe you can open some ports on AC56U and 8817 to avoid the problem? The easiest way to solve the problem is that replace TD-8817 and Ac56U with a wireless modem router...

What's the error message? Did you enable telnet? Start—>Control Panel—>programs and Features-- Turn Windows Features on or off---Select telnet client How did you telnet? telnet LAN IP port or telnet...

Local IP Address:192.168.1.1??? What's the IP address of your W8151N? Are you trying to open port for a server running on a computer or some device? What's the IP address of the computer or the...