Broadband upload speed? [closed]

Question

Possible Duplicate:
Why upload rates are lower than download rates in normal internet connections?

When you have an ADSL connection, you get something like 600 kb/s download and 50 to 100 kb/s upload.

Even when you upgrade to fiber optic, you have only about 1000 kb/s upload whereas 20'000 down.

With SDSL, this is not that much different, and the price you pay is much higher.

Is there a technical reason for the difference in up/down, or is that pure profiteering of the ISPs, which want to sell hosting ?

Answer 1

ADSL stands for Asymmetric digital subscriber line. Quoting Wikipedia:

There are both technical and marketing reasons why ADSL is in many places the most common type offered to home users. On the technical side, there is likely to be more crosstalk from other circuits at the DSLAM end (where the wires from many local loops are close to each other) than at the customer premises. Thus the upload signal is weakest at the noisiest part of the local loop, while the download signal is strongest at the noisiest part of the local loop. It therefore makes technical sense to have the DSLAM transmit at a higher bit rate than does the modem on the customer end. Since the typical home user in fact does prefer a higher download speed, the telephone companies chose to make a virtue out of necessity, hence ADSL. On the marketing side, limiting upload speeds limits the attractiveness of this service to business customers, often causing them to purchase higher cost Leased line services instead. In this fashion, it segments the digital communications market between business and home users.