"Can't Finish Multiplayer Tests" problem xbox one internet connectivity

So, I just recently got a xbox one, and I'm having some trouble with my router and/or modem... Whenever I go to test the multiplayer connection, my modem will abruptly cut internet and then slowly turn itself back on. While doing this, it makes it so it
can't ever do multiplayer -- however, it connects to the internet just fine, with an open NAT (and I can download games with no problem).

I've posted some specs below.

Modem brand & model number: D-Link DCM202 **This is the part that will temperorarily shut off whenever multiplayer is tested**

Router brand & model number: Linksys WRT54G2

How many 360 and One consoles are connected to this router?: One xbox 360 (wirelessly, no problems with this one), one xbox one (wired or wirelessly, still encounter the same issue).

Things you have tried: Manually opening ports 53 80 500 3074 3544 4500

Is UPnP Enabled? Yes

Do you have a NAT error? If so, what is your NAT type? NAT type is Open -- no errors there.

Any Error Codes you encounter: None -- it simply disconnects before a test is completed...

Who is your ISP?(Internet Service Provider): Comcast

Any help is greatly appreciated... I'm stumped.

:)

 

NAT Type Unavailable

for me it when I try and test my network connection it says everything fine but when I test my multiplayer connection it tells me it can't finish multiplayer tests in the home screen I can see my friends list and my profile but I can't message or invite
anyone I can't play multiplayer games and I don't look at the store to anything else that relies on Internet despite of what it tells me when I test my network connection.

 

"Can't finish multiplayer tests"

its been working the last two days so as long as that keeps up no issues. What happens is when i turn it to manual and change dns servers it says the dns isnt resolving xbox server names