DSL advertised speed question

[darthmilon]

I have DSL with advertiesed 1.5Mbps down and 384kbps up. alot of people tell me that these statistics are actually bits per second and not bytes per second. my max upload I've seen is 46kbps. Is this normal for a 384kbps upload or should I go yell at my ISP?

[darthmilon]

Also, on dslreports.com, I get the advertised ratings, so how come when I upload to people I max out at 46kbps even when I'm the only one theyr'e downloading from?

[Trent Steel]

Are the people you are uploading to on broadband as well, if not then it could be that their end is limiting.

[glc]

384 kbps = 48 kBps

8 bits to a byte.

Your downloads will probably top out at 187.5 kBps.

[Paul Victorey]

Originally posted by darthmilon I have DSL with advertiesed 1.5Mbps down and 384kbps up. alot of people tell me that these statistics are actually bits per second and not bytes per second. my max upload I've seen is 46kbps. Is this normal for a 384kbps upload or should I go yell at my ISP?

By definition, bps (small b) = bits per second, which is what ALL communications is rated in (e.g. a 33.6K modem is 33.6 kilobits per second).

On the other hand, Bps is bytes per second. This is *not* exactly the same as 1/8 of the rating in bps (although it will be close) because the communications channel speed includes control bits (start/stop/parity/etc.). For example, on a serial communications channel with 8 data bits and parity, each byte takes 11 bits to send. Depending on the type of communications channel you use, the overhead can be large or small.

So, your actual max speed, in bytes/sec, will be close, but a little less than, 1/8 of your bps rating. Also, it will be lower because of software overhead -- each packet you receive also has headers, etc.

Essentially, Bps measures how much application data you move, bps measures how many total bits are exchanged.

[Xayd]

And if you're getting 46 of 48, you have a very clean line. You're getting the best there is to be got .

[Byte 2.0]

GLC's numbers are correct.

Also, most DSL's connections are listed as a best effort , not a guarantee.

I do tech support for one type of DSL and the max speeds are suppose to be 1472 kbps down and 256 kbps up.

so that is a max speed of 184 kBps download and 32kBps up.
but to make it easy for customers to understand, I normally tell them to devide by 10 and get 147.2 by 25.6 and tell them that is a speed they should expect as a max. But then I don't always use max numbers for I can check the actually speed they Sync up at AkA(their DSL foot print) and they might have sync at 980 by 256 due to line condistions. so i tell those ppl there max speed would be like 98.0 by 25.6. yes those numbers are off a bit but I do that because there are other factors that account for your over all DSL speed, such as noise on the line, line loop lengh, attenuation. RFI/EMI , System resources, etc, the list can go on and on.


if a customer has slow speeds, we don't do anything unless their download speeds are down around 250 on the downstream. Normally I will check out there system for problems and such, but getting anything on the line done is basically impossible.