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NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:12
Reviews:
·SONIC.NET
·Pacific Bell - SBC
reply to Ernest House

Re: ADSL Filters and other Prep for Self Install

said by Ernest House:

I am keeping voice on POTS and replacing existing AT&T DSL with U-verse 12MB internet.

My DSL is capped at 3MB speed and my modem could only ever connect at 2.2 at the NID so I am skeptical that a 12MB U-verse self install is going to work smoothly.

Do you know your modem stats? Per the AT&T ToS, they sell a data connect rate, but this includes the ATM encapsulation. So, figuring the encapsulation overhead of ~15%, a modem on the 3.0 Mbps tier will sync at 3008 kbps down, but only deliver ~2500 kbps throughput. So your experience sounds about right.

Knowing the SNR and line attenuation would be helpful for prediction. I used to have, "at&t Yahoo! HSI Pro" (3008/512 profile). With SNR=11.0 dB and attenuation=51.0 dB, that was the highest tier I qualified for. Higher SNR and lower attenuation are better.

BTW, "U-verse HSI" does not use either PPPoE authentication, or ATM. Authentication is 801.1x, and the transport network is PTM. You should get closer to 96% of your modem sync, not the ~85% you currently see. And, without the PPPoE, you should set your MTU to 1500.

My Suttle 694A XDSL splitter is installed at the NID and a CAT5E goes straight from there to where my modem is.

Does the Self Install come with those inline filters for VDSL?

Shall I leave the Suttle installed as-is and just put the VDSL filters on each phone indoors?

AFAIK, that Suttle splitter can remain in place, and you won't need to use the inline filters.

I've had problems in the past where the AT&T modem only supports one computer at a time. Does the U-Verse 2wire HGV3800 modem allow more than one computer?

I am certain that the 2Wire has a four-port router built in. So up to four wired devices (more would require a switch), and up to 253 devices total (mixed wired and wireless).

You must have had a really ancient DSL bridge to hit a one-device limit. Though not supported, any modem subsequent to the SBC-issue Siemens Speedstream 5100B had a routing table, and a Class B subnet (default 192.168/16).

Any gotcha's I should be aware of?

Other than the MTU issue, I can't think of any. And I expect the 2Wire will have the proper MTU out of the box.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum

Ernest House
Premium
join:2008-08-17
Boca Raton, FL
Thanks for the well written and informative response NormanS.

I've had DSL to this location for 10 years and it seems the wiring to my house is the weak link. I attached my current stats.

My last go around with AT&T was about a year ago when their little Motorola modem died. It allowed multiple computers via my own switch etc but the replacement Moto had upgraded firmware that did not allow multiple computers and I had to buy a more expensive Westel. That was AT&T choosing to force an upgrade and hamstring the Motorola.

I have a network with 2 switches and a 2 wireless access points that have outlasted all the AT&T gear 3 fold. I really just need the modem capability end up paying for the whole 9 yards. Looking forward to the faster speed though.


NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:12
Reviews:
·SONIC.NET
·Pacific Bell - SBC
With those numbers your line will need some work. When I had ADSL from AT&T, my modem bit loading chart suggested a MaxSync of ~5400 kbps was possible; but they capped to the 3008/512 profile.

Ah, found a picture:

SS4100 bit loading chart.

My reported modem stats were 3008/512 with 11.5 dB SNR and 51.5 dB attenuation. Loop length was 9,156 feet.

Line stats.

Alas, I have no screen shots of the ZTE ZXDSL 830II ADSL2+ modem supplied by my new ISP, Sonic.net, LLC. On the same AT&T copper, the ADSL2+ sync rate is ~5900/500, with 6.0 dB SNR and 51.5 dB attenuation.

As your numbers are now, you are not going to do much better than your current speed on their IP-DSLAM service.

I would recommend a post in the AT&T Direct forum. Link this thread, and show them those numbers. If they can do something to improve your stats, that would be helpful. But, assuming the 57 dB line attenuation is an accurate reflection of the loop length, I don't see how they can give you better than 3.0 Mbps service; even with ADSL2+.

Interesting about that modem. I ran the Siemens SpeedStream 4100 for 5 1/2 years with AT&T, and, interchangeably with the ZTE ZXDSL 830II on the Sonic.net "Fusion" service for another six months (at 9,156 feet, I saw no appreciable difference in sync/speed between ADSL and ADSL2+; the benefit of ADSL2+ needs a shorter run of copper to be manifest).

Two others, that I know of, have run nearly as long.

My good friend in the Fruitdale section of town has a Motorola that's been in steady use for about the last four years.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum