2013-10-15


For those looking for faster internet speeds with AT&T's latest U-Verse product offering, I'm afraid that there are a lot of current subscribers unable to get or upgrade to the new speed tier. The new speed tier requires VDSL2 Pair Bonding, a technology used to increase the available bandwidth to a customer s premise. Thus, A large majority of U-Verse territory is not eligible for the new Power Tier offering 45 Mbps downstream and 6 Mbps upstream.

Do You Qualify For AT&T's Latest Upgrade?

Persons living in MDUs (apartments, condos, duplexes, townhouses, etc) are typically disqualified from Pair Bonding at present. Typically you are considered an MDU location if your point of demarcation/NID is "shared" with other units in your building. There are instances, typically townhouses, where individual units in a building will have their own NIDs - those are typically considered SFUs and would thus qualify for VDSL2 pair bonding.

Also, at the present the faster option is not available to ADSL2+ or xPON customers since pair bonding must use VDSL2. There are also rather strict loop length limitations from the neighborhood VRAD to get these new speeds. Users who find that they qualify on the website and have a tech come out to install it may find themselves disappointed as well.

Current and new subscribers eligible for the "Max Turbo" (24 Mbps speed tier) have the best chance at possibly getting manually qualified for the new tier. To have this done, any AT&T customer and dslreports.com user may post a topic requesting this manual qualification in the AT&T Direct Forum. The techs moderating the forum will do their best to qualify you for the tier, within a reasonable period of time. Just ask!

The Power Tier uses pair bonding technology, a solution that combines multiple copper wire pairs to increase available capacity and/or extend the copper network's reach. There are many factors that come into play to be able to get the new service provisioned -- such as whether or not your home is serviced by a VRAD using VDSL2.

Currently if you are a DSLAM or CO serviced address, ADSL2+ is used instead of VDSL2, thus disqualifying such addresses. These same factors also dictate the availability of U-Verse in general as well, but are more sensitive when it comes to provisioning the Power Tier, especially when combined in a "triple play" package including IPTV, VoIP, and the Internet. Some of these provisioning factors include:

• Length of the copper loop serving your home from the VRAD (for a visual representation of how U-Verse is delivered to you from VRAD over copper pairs, see FAQ: How is U-Verse delivered to me over copper?

• Copper cable gauge between the VRAD and the DEMARC pedestal (affects attenuation numbers)

• Quality and age of the copper lines between VRAD to Crossbox and DEMARC pedestal.

• Strength of the noise (in dB) affecting the VDSL2+ signal (SNR margin), noise can include AM and amateur radio signals, as well as crosstalk between adjacent pairs of lines used to provision U-Verse.

AT&T U-Verse VDSL2 customers currently served from a VRAD use the 8d profile. This includes the pair-bonded connections as well. Sometime in the future, as AT&T has announced, customers could see a 75 Mbps and 100 Mbps speed tier available to them, in accordance with the "Project VIP" program to extend AT&T s copper network bandwidth and the lifespan of copper networks as we know it.

Since AT&T wants to ditch their wireline business altogether, the only way for them to compete in the ever expanding bandwidth market is to ditch copper, and focus on wireless and fiber deployments. To the right you'll find a table of VDSL2 profiles available to serve customers based on their bandwidth needs.

What U-Verse is and How It's Deployed

Let's start by understanding what U-Verse is and how it is deployed out in the field. VDSL2 is the newest and most advanced standard of digital subscriber line (DSL) broadband wireline communications. Designed to support the wide deployment of triple play services such as VoIP, data, HD & SDTV, VDSL2 is intended to enable AT&T and other telcos to gradually, flexibly, and cost-effectively upgrade existing xDSL infrastructure.

VDSL2 deteriorates quickly from a theoretical maximum of 250 Mbit/s at source to 100 Mbit/s at 0.5 km (1,600 ft.) and 50 Mbit/s at 1 km (3,300 ft.), but degrades at a much slower rate from there. Starting from 1.6 km (1 mi) its performance is equal to ADSL2+, which will also be discussed because those getting U-Verse internet may be IP-DSLAM (CO based) and use ADSL2+ which cannot support such high bitrates.

ADSL2+ is used where customers can only be served from DSLAMs, almost exclusively located in central offices, however they can be remotely located and connected to a neighborhood crossbox. The remote DSLAM runs on essentially the same concept used where VRAD s serve VDSL2 to a neighborhood. ADSL2+ extends the capability of basic ADSL by doubling the number of downstream channels.

The data rates can be as high as 24 Mbit/s downstream and up to 1.4 Mbit/s upstream depending on the distance from the DSLAM to the customer's premises.

VDSL2 can achieve speeds of 100 Mbps both upstream and downstream, but that is over very short loop lengths of 1000 2000 feet. These speeds are faster than any of the other DSL technologies to date. As a result, VDSL2 has become the choice technology to deliver triple play services from the fiber-to-the-node (FTTN) distribution network.

ADSL2+ more than doubles the data rate of ADSL2 by providing a maximum of 25Mbps downstream on loops as long as 5,000 feet. It accomplishes this by increasing the spectrum used from 1.1 MHz to 2.2 MHz. ADSL2+ can also bond channels in the same way ADSL2 does to achieve even higher data rates. The main application for ADSL2+ has been in provisioning voice and data services to customers serviced by a digital loop carrier (DLC) system.

The Install

Since I've had the new faster option installed, I can offer a small glimpse at the process, which is relatively simple if you qualify. The tech first adds a pair at the crossbox, then connects a new pair at the pedestal. From there, the tech adds a pair in NID from line drop connected to the pedestal, connects the pair bonded lines together into one RJ-11 jack, and connects the line to the NVG589 U-Verse gateway.

All of that said, I'll leave you with some photos of my install. Here the U-Verse tech is at the crossbox adding a line into our "card" and the line stats on the single pair at the crossbox: att=2131861 Here's the line stats using his handy tool: att=2131854 My speed test is available here, and here's my final line stats for the technical among you that are interested: att=2131857
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