While the 6-10Mbps offered by AT&T's "next-generation" U-Verse service might be plenty for standard users, it's still not going to be enough to battle cable on the marketing front -- particularly once cable begins deploying DOCSIS 3.0 technology. To that end, AT&T has been promising for the last few years that they're going to offer faster speeds via bonded VDSL2. However, early reports indicate this hasn't been an easy process so far -- with some estimating that AT&T U-Verse customers may not see faster speeds until late 2009 or even 2010.

All U-Verse customers are not created equal. We've seen reports of U-Verse gateways syncing at nearly 100Mbps, though we're talking about only 1,400 feet from the DSLAM. It seems that 25Mbps is working well at distances of 3,000 feet; distances higher than 5,000 feet are where the trouble starts. Of course many users are further than 3,000 feet -- and with AT&T now offering dual-HD streams, things are quickly getting pinched. This pinch is why AT&T recently had to change their TOS to better manner customer speed expectations.

AT&T's decision to run FTTN instead of FTTH has remained a sticking point with most analysts. "Fiber to the node (FTTN) is just DSL from a cabinet and a press release," says industry analyst Dave Burstein, who believes that cable will "clobber" FTTN, provided cable prices competitively. Where Comcast faces U-Verse competition in Florida, they're already beating back U-Verse with their last-gen 16Mbps "Blast!" tier, saving their heavier guns (pre-cert 50Mbps DOCSIS 3.0) for areas that see FiOS deployment. However, that service costs $150.

Pair bonded VDSL2 will be AT&T's retort, with AT&T enlisting a second copper pair to each house to increase speeds. AT&T says they should be able to double the bandwidth they're currently delivering, though other estimates peg the speed bump at closer to 25-30%. Others still insist estimates are premature, since we're still in the testing phase. To offer bonded VDSL, AT&T needs to assign two DSLAM ports to each customer, and deploy a special residential gateway outside the house that can terminate two pairs -- assuming they're available.

But things are moving slowly. "As far as I can tell, nobody has seen a bonded VDSL2 modem ready for the field, while those in lab trials are having problems," says Burstein. One vendor tells Burstein early samples "are not up to speed," while training installers and support will also take time. "There's almost guaranteed to be a significant delay after the manufacturers get them working," he says, and they aren't working yet.

In 2007, AT&T promised bonded VDSL2 would arrive sometime in 2008, though Burstein thinks that's doubtful. "Bonding doesn't work yet, and they be lucky to be able to do it in late 2009 in any quantity," he says. Given that many cable companies are taking a wait and see approach with DOCSIS 3.0 upgrades, that may be ok for AT&T -- assuming the general consumer remains happy with 6-10Mbps downstream and 1Mbps upstream.

AT&T insists that things are on schedule. "We're planning an initial launch of pair bonding by the end of the year, and we've started testing on track with that schedule," AT&T spokesman Seth Bloom tells me. "It is worth noting that pair bonding isn't necessary for all customers, nor are things like 2 HD streams or faster Internet tiers dependent on pair bonding," insists Bloom.

In AT&T's opinion, pair bonding is more about selectively reaching out to customers at greater distances, given not all homes will see an available extra pair. "We'll use pair bonding where needed," says Bloom, "as a way to expand our U-verse service area to customers at longer loop lengths." "It will allow us to reach a broader customer base," he says. Theoretically, bonded VDSL2 may be able to provide 40Mbps and 5,000 feet but again -- that's yet to be proven in the field.

Time will tell how exactly AT&T chooses to deploy the technology and when, but for most U-Verse users, anything faster than 6-10Mbps could still be a year or two out. A longer delay in getting this next step in "Project Lightspeed's" evolution into the field could make cable operators very, very happy.