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NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:11
Reviews:
·SONIC.NET
·Pacific Bell - SBC
reply to Archangel83

Re: [Speed Problem] DSL Information

said by Archangel83:

Hi I'm new to dsl I have been using cable modem for along time as I lived in the country and had no access to dsl. But now I moved into a city center and a friend told me adsl was the way to go for gaming because of the lower latency then cable modem can give you. I logged into the modem which is a motorola 2210 and was interested to know if what my modem is getting is good can someone tell me what all this means?

• Modulation = DMT

Odd. Not "g.DMT"? ADSL should be reporting, "g.DMT".

• Data Path = Fast ...

This is good for low latency. Should see ~10ms on your first IP hop.

• Max Allowed Speed = 6016/768 ...

This is good. It means your connection speed is at the AT&T tier limit.

• SN Margin (dB) = 17.0/20.0 ...
• Line Attenuation (dB) = 14.0/6.0

These are good. It means you are on a fairly short copper loop. Should easily get faster speed with ADSL2+. 8192/896 are the upper limits for ADSL service, but those numbers suggest that ADSL2+ could go to 18000/1500. Should AT&T offer you the "U-verse Internet" service, you should easily qualify for the 12/1 tier; maybe even the 18/1.5 tier. (Don't quote me on those U-verse tier numbers; my memory isn't as sharp as it once was.)

Also for my speed when downloading I never get more then 600-614 kB/s am I getting my promised bandwidth of 6.0 Mpbs?

AT&T ADSL is delivered over an ATM backhaul. Encapsulation of data into the ATM cells takes up ~15% of your bandwidth. So D/L speed will be ~sync*.85. where "sync" is your modem sync rate: 6016*.85=5113.6. But download managers generally report speed in Bytes, not bits. Eight bits to a Byte, so kbs/8=kBs: 5113.6/8=639.2. Allowing for variable end-to-end conditions, you appear to be getting the best download speed for your connection. Coupled with the low latency, you have it as good as it gets for an ADSL connection. Almost ...

Remember: The 'at&t Yahoo! HSI Elite' service is ADSL over ATM with PPPoE authentication. You have to set MTU=1492 because of the PPPoE, and your actual measured download speed will be sync*.85.

When AT&T gets around to offering 'U-verse HSI', what they will give you may be ADSL2+ over PTM with 802.1x authentication. You will be able to set MTU=1500 because there is no PPPoE. And your download speed will be sync*.96 because there is no ATM. And your download sync will be 12000/1000, or even 18000/1.5 because of the ADSL2+ on such a short run of copper. With fastpath, you will still have low latency.

But if they give you VDSL instead, everything will be the same as ADSL2+, except for the data "path"; you will be on interleaved, and latency will suffer.

And, no; if they offer the U-verse upgrade, you likely won't be able to keep the ADSL service.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum

Archangel83

join:2009-11-02
Reviews:
·AT&T U-Verse

Thanks for the info I'm pleased with the service I get and yes the UVerse is in the area and would need to buy a new modem for it as I have no use for TV just Netflix,Hulu,And OTA DTV. My understanding is if I go for just the uverse dsl it won't be delivered on the vrad but will still use the fastpath method is this correct?



NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:11
Reviews:
·SONIC.NET
·Pacific Bell - SBC

With or without TV, U-verse would require a new modem. I believe U-verse HSI can be delivered from the VRAD. U-verse HSI from a CO is likely to be ADSL2+, but from a VRAD can be either.

I believe ADSL2+ can be fastpath. I've heard that VDSL is normally interleaved; but maybe that is only for IPTV, not IPDSLAM.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum