Poor Netflix Streaming Quality

There can be a large number of factors impacting Netflix streaming.  One of them is adequate connection bandwidth; you seem to have addressed that (16 Mbps is more than you need for any Netflix offering, even 3D).

Assuming that you consistantly get 16 Mbps, then the issues could be latency or latency jitter (varying degrees of latency), or it could be congestion in the network away from your home, (for example, between the Netflix Content Delivery Network (CDN) and the AT&T Network), or varying levels of wireless interference inside your home (which wouldn't apply to your Xbox, obviously, but could affect your TV).

To elimnate the factors in your home, test with another streaming video service, such as Hulu, YouTube, Amazon and see if the results are the same.  If not, then it points to an issue with the Netflix delivery.  If so, then it may be an issue with your U-verse equipment/connection or inside your home.

If multiple devices have the same problem with Netflix, but not with Amazon Instant Video, then it appears to be a problem with the Netflix CDN serving your area getting congested feeding your segment of the AT&T network.

One thing you can try is to reconfigure the XBOX to use a different DNS server from the AT&T default.  AT&T will chose a Netflix CDN server based on your location.  Switching to a Google DNS server (e.g. 8.8.8.8), or OpenDNS or anyone's really, will likely send you to a different Netflix CDN server and may (or may not) give you a better experience.  It's worth trying, anyway.

Thank you both for the information. I'll chancge my DNS server from AT&T to Google to see what happens. Hopefully that will help the issue. According to the one article 4mbps is good enough to stream HD. So I should be able to stream... Will report back later this evening as to what I find out about the DNS change.

So there is apparently a setting in your Netflix account on how the video quality should be that is streamed. I set this on 'Best'. Then I used the NameBench tool from Google to determine my best DNS options. Once I plugged those two IP's into my Xbox, I tried out Netflix. I was getting 2 bars, then it would go to 3 and then the HD would light up. So throughout 2 episodes of Walking Dead last night, I had full signal and HD! I did not try it on my other TV that is connected wirelessly, but will change the DNS on it tonight and try to stream to it and see if HD appears.

My understanding of streaming on a device other than a computer, is that another server is part of the process--normally the provider of the device you are using.  As evidence of this, when you buy a device from Roku, Vizio, Sony, etc. the first thing you have to do is logon with a computer to some page, like "netflix.com/roku" and enter a key from your device.  [Please someone correct me on this, if I am mistaken.]  So the path for your stream is Netflix to Roku to your device, rather than Netflix to your device direct, which means there are at least three major parties to your Netflix movie stream:  ISP, YourDeviceMfr's Servers, and Netflix.  Any of the three can be a bottleneck.

For example, Sony DVD players with streaming were (and maybe still are) infamous for their streaming problems.  Many people have given up on streaming HD on a Sony DVD player, attributing the problem to Sony's inadequate servers or bandwidth.  I'm one of them.  A couple years ago I replaced a Sony DVD player for streaming with a Roku XD.  Immediately my streaming issues went away, and the Sony DVD player became just a DVD player.

Recently, though, I've noticed problems with Netflix streaming.  The failures are almost always at what I imagine are peak times:  evenings, weekends, holidays.  Roku has a streaming meter along with a "loading" bar which flies or creeps across the screen, accompanied by an indicator at the end with 1, 2, 3, or 4 dots and HD.  Best case, HD stays on, and you get an HD picture.  If the stream is inadequate for HD, the HD symbol disappears, and you see four dots.  If still inadequate, then the fourth dot disappears.  A "three dot" picture is something less than old-time TV resolution.

When that happens, I'll turn on a laptop or iPad and check speedtest.net to see if my speed is the issue.  Normally, I'll see a ping of 20-40 ms and down/up speed of 17.25/1.49 on my 18/1.5 Uverse connection, so I know that is not the issue.  I will next check Amazon Prime to see if they have the same program available, and they often do (but not always "included in Prime").  If it is available and free, I'll check the quality.  More often than not, Amazon's quality is better.  That is, I get three dots with Netflix and four plus HD on Amazon.  That would seem to point to Netflix as the problem, although I am not certain.

FWIW my Roku is wireless, but I'm not using the 3800HGV for wifi, but rather an 802.11(n) wireless access point, so the wireless is not a bottleneck, and the Roku reports "Excellent" as my connection speed.

In short, I have the same problem as your XBox with my Roku, but I have no solution.

Last night the quality on the 360 was horrible. The best that I could do was 2 bars, but it usually dropped down to 1 bar. So I tried the TV and streamed a movie in HD just fine using the TV app. So I guess Xbox Service may have been overloaded last night?