This is probably not the right forum for this topic. But here is some help. Your DSL will rarely achieve the speed that you pay for because of overhead in the system. To find out your DSL speed, connect your Westell to your computer or laptop with an Ethernet wire and test it. Your Wifi should have about the same speed but then again, it depends on your wifi hardware and environment i.e. distance and obstacles etc..
OK, so Westell is giving you some problem. The Asus RT-N56U is a pretty good router. What you need to do is to log in your Westell and set it up as a bridge, that will disable its router function. Connect the Westell to the Asus Internet connection (blue) and enable DHCP on the Asus which now will provide all the router function. There are many DSL modems that you can buy and replace the Westell altogether. I had DSL for many years and found that separate modem and router works best for me. I am now on cable broadband with an Asus Rt-N66U.
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