ADSL connection too fast... any explanations?

No replies to this question in the GoneGold forum so far, or maybe they thought I was just kidding… but I’m serious! My connection is too fast! :shock:

I recently got ADSL, with a specified speed of 128/768 kbit/sec, but the downstream speed I’m actually getting is a whopping 860…890 kbit/sec. This is for pre-compressed data (installation packages), as reported by the connection manager. GetRight says I get close to 90 kbyte/sec which makes sense if we assume the usual 2 error correction bits per byte.

Not that I’m complaining but out of idle curiousity… does anyone have an explanation for this excess speed? Are the error correction bits possibly transferred on another frequency band, simultaneously with the data bits? Or maybe someone’s got a link to the technical specifications for ADSL?

ADSL can work at up to 8Mbps download. Most service providers set artificial limits on download rates so that they can charge you extra if you want more bandwidth.

They guy at your service provider who set up your account probably entered the wrong limit. He probably gave you a 1Mbps limit instead of 768Kbps.

Hmm, I guess that’s possible. Come to think of it, my connection monitor does show “connected at 1.0 Mbps” when starting up but I thought this was just the speed of the USB connection (the modem’s hooked up to a USB port). Well, I won’t be giving my provider any ideas about fixing my connection speed! :D

"Well, I won’t be giving my provider any ideas about fixing my connection speed! "

At least not until you get your first bill. Maybe they did some ‘creative marketing’ on ya.


Sounds similar to when I first signed up for Comcast cable-modem service. The service is set to 1.5Mbps downstream, 128Kbps upstream, but when I started with it I was getting about 4Mbps downstream, 2Mbps upstream. After a week of this, and realizing it was consistently this fast, I started using my comp as a private FTP and game server for my friends. This actually last for about 3 months, and then suddenly my downstream was clocking at 1.2-1.5Mbps and my upstream a measly 128Kbps. Oh well, I guess they eventually realized that my connection was uncapped, and fixed it.

  • Balut

Heh, don’t think so – they aren’t even selling a connection faster than the standard 128/768 provided by Deutsche Telekom’s T-DSL service. Besides, I get 100 hours/month for free anyways and I don’t think I’ll manage to exceed that time!

If you’re in CA and get your DSL from SBC, the numbers they quote you are a guaranteed speed and you may get higher downloads depending on the quality of your cables and proximity to the CO. My DSL was a 768k download guarantee, but I maxed at 1.5mbit on a regular basis.

That SBC guarantee is nice… but some carriers will only say you can get up to the advertised bandwidth on the line, which is a bummer when you are paying for 5 Mbps but only actually get 500 Kbps. There can be various technological problems with the equipment in the CO and the ATM network behind it which give you less than the max, even ignoring the issues of distance and signal degradation.

Furthermore, that bandwidth you may be guaranteed is loop bandwidth. “Of course,” you say, “I know that, any random Internet connection may be much slower due to bandwidth issues on the Internet at large or due to server load.” Not so fast; there is more private network to worry about in between the local loop and the public Internet. The intervening ATM cloud and the interoffice circuits that connect to some Internet backbone site will typically be concentrated in a fairly narrow trunk like a DS3. This means that while your loop bandwidth is unaffected by the number of subscribers in the area, your actual bandwidth can still be reduced if DSL becomes popular in your neighborhood as the DS3 can become saturated. The carrier should but is not obligated to engineer that trunk to support the average required bandwidth; and in any event the odds are very very good that worst case required bandwidth (when all the subscribers are logged in and downloading the same LoTR trailer) will vastly exceed the bandwidth of the external trunk.