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I've just moved into a new house (new for me; the house was built in 2006). I've purchased DSL service through AT&T, paying for speeds "up to" 768 Kbps downstream / 384 Kbps upstream. My issue is, the connection speed on the DSL is very slow -- the DSL modem connects at 224 Kbps downstream / 128 Kbps upstream, as reported by the modem's own built-in control panel applet (accessible at the internal IP

However, my brother-in-law, living 9 doors down on the same street (and further from the local CO -- if the CO map at is to be believed), connects at a much more comfortable 1.5 Mbps downstream / 384 Kbps upstream. He has the same service from AT&T (although he's paying extra for the 1.5 Mbps service).

I'm not sure whether it matters, but I have a "dry" DSL connection -- DSL service only, no phone service.

I've tried the following:

  • Switching modems. I actually tried borrowing my brother-in-law's modem, that connects at 1.5 Mbps from his house; replacing that modem with the one at my house, it also connects at 224 Kbps. Both modems are the same model (Siemens SpeedStream 4100).

  • Connecting the modem directly to the phone jack on the outside of the house (to rule out the possibility of bad wiring inside the house). No change, the modem still connects at 224 Kbps.

  • Switching phone cables. No change.

I'm not sure what else to try. I did contact A&T; they informed me that they consider a connection speed of 224 Kbps to be "acceptable" for a customer paying for 768 Kbps service. Interestingly, AT&T did inform me that 1.5 Mbps service isn't even available at my location, based on an on-site test they performed recently (presumably of signal strength / quality).

So, my question has two parts:

(1) Why is my DSL connection speed so much slower (more than 6x slower!) than the service my brother-in-law is getting, when we're located in almost the same location (9 doors down on the same street)? (If the reason is that my DSL signal is weaker and/or poorer quality, then why might that be the case?)

(2) Is there anything I can do to improve the situation, short of dropping the DSL service (and paying significantly more money for cable)? The 224 Kbps connection speed is okay for email and surfing the web, but it's poor-to-unusable for large downloads, gaming, and YouTube.


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+1 Very well researched articulated question! – nhinkle Apr 3 '11 at 20:01
up vote 14 down vote accepted

A very helpful AT&T tech that came out to my house ended up solving this issue for me.

  • The tech measured the signal quality at the point of the phone/DSL wire coming into the outside of my home. The signal quality was just fine at that point (to my surprise)!
  • The tech measured the signal quality at the phone jack inside my home where I had my router and DSL modem plugged in. The signal quality was very poor at that point.

This proved that the problem was with the wiring inside my home. (Again, this was to my surprise, as I live in a fairly new home that is, in other respects, well-constructed.)

  • The tech took a look a look at the wiring down in my basement. He offered a diagnosis that the problem was due to the phone wire being run throughout the house bundled together with the electrical power wire. Apparently, per the tech, this can cause interference/"noise" on the phone line, which can adversely impact the DSL signal quality.

We ended up solving the problem by physically disconnecting, at the junction box in my basement, all of the phone lines running throughout the house except the single line leading to the jack upstairs where I had my DSL modem plugged in. (I didn't care about doing this, as I wasn't using any of the other phone jacks in the house.) This did solve the problem for me, and I now have no issues with my home DSL.

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This is extremely common. IW (inside wiring) is the most common leg of a DSL connection to be faulty. I've seen fluorescent lights, ac systems, microwaves, alarm systems and much much more cause "noise" or other sorts of interference on lines that DSL is running over. DSL is very easily interrupted. – MaQleod Apr 3 '11 at 19:55
I'm surprised you didn't do that before having dry DSL installed. It's standard pre-installation preparation. – David Schwartz Nov 23 '13 at 5:21

Have you had AT&T run line tests? There are tests they can do remotely to tell line noise, etc..

Is your phone line going through any UPS's, filters, splitters, etc.?

You may need to have your house's wiring checked. There could be a bad spot somewhere. You could take your DSL modem to the actual junction box (outside of your home) and connect directly in there to see if speeds improve. Most of the phone junction boxes have a "provider" side which is locked (AT&T's) and an "owner" side, which is accessible to you. Inside the "owner" side you should be able to unplug your entire house's line and plug the modem directly in there.

Have you tried swapping out modems? Does your brother-in-law have the same exact modem?

If things still aren't working right after these suggestions, you may need to have AT&T send out a tech, but if they find any wiring issues in your home, you'll pay for it. Otherwise it's (usually) free if there's something on their end/outside wiring that is screwy.

Lastly, you could try going with a different DSL company temporarily and see how they do.

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Thanks for the response. I have tried all of your suggestions, though (as noted under "I've tried the following" in the original question), short of switching to a different DSL company. How could switching DSL companies help? Would there be a different CO? According to the map, there's only a single CO in my vicinity. Given this, could switching companies still help? – Jon Schneider Aug 19 '09 at 2:10
Switching companies probably wouldn't help as it'll go through the same lines and the same CO. – mrdenny Aug 19 '09 at 3:39
So how is your accepted answer (your own) any different than what I suggested? I even said you probably need your house's wiring checked :) – Nicholas Head Nov 14 '11 at 15:56

Switching companies could help if AT&T is in fact limiting or capping your connection speed, the other company hopefully will not.

You did not mention how far from the CO you are, if you are near the maximum distance for DSL from the CO, that could be a factor as well. Your phone line does not alway take the most direct route back to the CO either, you could have a longer cable run compared to your brother-in-law even though he is physically closer to the CO. Depending on your distance from the CO, the line could have gone somewhere else from one of the distribution boxes along the path and that other line may not have been removed, resulting in the line splitting along the path from the CO to your location. That would cause extra noise on the line. If that is the case, switching companies would not help as the local loop would still be provided by AT&T. Good luck.

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I think I'm about 7500 feet from the CO "as the bird flies". If the phone wires follow the main roads, it might be more like 10000 feet. I think either figure should "theoretically" be fine -- although obviously this is small comfort since I'm still having problems. :-) Thanks for the tip about the local loop and AT&T, I probably won't try switching DSL companies, except maybe as a "last resort." – Jon Schneider Aug 19 '09 at 12:13

There's probably a problem with the line between your house and the CO. Unfortunately if AT&T won't fix it there's not much you can do besides look into a cable modem. They own the line, and until the line fails, or there is an audible problem on the line when making voice calls (since you don't have voice service that'll be a tough sell).

Other problems could include line noice from an outside source. An example would be an gable fan which isn't properly grounded and the power line runs parallel to a telephone line in the walls somewhere (I had this problem until I disconnected the phone line that ran in the rafters).

You said that you tried connecting the DSL modem outside. When you did this, did you disconnect the rest of the house from the tele-co?

Try plugging a normal phone into the line and pick it up. Do you get dial tone? Does it sound correct? Even though you don't pay for voice, that line should still be active on a voice circuit so you can use it to call 911. If it sounds bad, you can call in and tell them that and see if they'll fix it that way. (You can try lying to them, it worked for several customers we had do it when I worked for an ISP.)

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Yes, I did disconnect the rest of the house when I plugged in outside, so presumably the problem isn't any wiring issues internal to my home. I haven't tried plugging in a voice phone, though; thanks for the tip, I'll give it a try. – Jon Schneider Aug 19 '09 at 4:41

Sometimes mentioning (or writing to) the PSC and the FCC will force a telephone company to actually do what they have contractually agreed to do.

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ILECs are only obligated to provide phone service, not DSL service. As long as a phone will ring on those lines, it is not a concern of the phone company to provide good enough lines for a DSL signal unless you are their customer, or their contract with the CLEC requires a minimum specification. No ILEC or CLEC will EVER guarantee the IW. – MaQleod Apr 3 '11 at 22:25

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