Wireless Router Behide Wired Router.

I just switched from cox to u-verse and they have provided me with a modem/wireless router with 4 ports. I also have Vonage. the problem is that the wireless router provided by AT&T is G vs N ( like my prevous router: ar680w airlink101) so what I want to accomplish is turning off the G wireless from AT&T router and hooking up my 300N-airlink.

I tried hooking up port 1 of the AT&T router to the broadband port of my router. but it will not work. I tried this with the vonage box and it worked perfect. can some one help me on this.

I currently have it hooked up like this.

MODEM-Port.1>> Vonage box/router (broadband)then from port 1 to my 300n airlink broadband.

DMZ is turned on, on the vonage box/router.