All AT&T U-verse transport types use 802.1x authentication. This means only equipment on AT&T's approved list works with the U-verse service, as other (non-AT&T) equipment cannot authenticate with AT&T DSLAMs and GPONs. Another side-effect of U-verse's authentication protocol is the lack of bridge mode support (unlike standard DSL that uses PPPoE authentication, which is easily bridgeable). At best, the 2Wire/Pace routers support DMZ+ mode, while the Motorola devices support IP Passthrough. AT&T allows residential and business customers to pay for static IP addresses, which they support on all AT&T approved equipment (including the 2Wire/Pace and Motorola routers.)