Arcadyn IP Address

I'm fairly knowledgeable about networking and have some devices with fixed IP addresses.  Quite frankly, the Arcadyn doesn't work well enough for me to justify all of the work it will take to make it function as I want.  It's also too difficult to deal with T-Mobile's tech support as they won't let you talk with anyone who really understands the issues.   Will probably just return it.  Thanks for responding.