Couldn't hurt going the cat5 (ethernet) route if you can, since it takes any possible wifi incompatibility variables such as mode (a/n/ac, etc.) out of the equation. I'm getting great speeds on my 360 going direct. Pulled a 6.5GB game down in ~20 minutes flat just the other day!
If you prefer to experiment with different connections, try varying the modes, bandwidths and channels until you get something that works well. If you have a wifi scanner on your computer that tells you who else is using the channels in the area, that could be a bonus, since it would help debug your setup and help you avoid interference from someone else; e.g., 802.11ac uses up to 4 full wifi channels for max bandwidth/speed that it needs on the HT2000W.
I just got Hughesnet today and I'm getting the MTU error on my 360. I have it connected directly to the modem via Ethernet, I tried setting up the port forwarding per the 360 page, I tried turning uPnP off, tried resetting the 360 network settings back to factory default.
Did anyone ever figure out how to fix this?
Would an XBox One work any better?
Forget about the port forwarding. It won't work on the 360.
Plus, because of that, the "test" always gives you a semi-fail result. Ignore it. As long as it thinks it can get to the internet, and you can physically login to XBox Live, it's fine.
It might say that right after you set it and it tries to log in. Especaially right now, since I think XBL is having problems (I'm even having problems signing in). Try these using wired mode (ethernet, not wifi):
I use a static IP: Manual
Address: 192.168.42.105 (your last octet might be different, but first 3 should be similar).
Gateway: 192.168.42.1 (Router)
Primary: 192.168.0.1 (Modem)
Secondary: 188.8.131.52 (Google)
PPoE - all not set
Advanced - all not set
It might give you a hassle about the last step, but like I said, ignore it. As long as it goes from XBox->Network->Internet, it's fine. Just go to the Network Statistics and do the remaining testing from there.
I already had it connected via ethernet, but I think the problem was with XBL since it connected fine tonight without making any changes.
Thanks for the help!