I like Nihil's response, but since you didn't think it was relevant here is a link for testing your DSL line. http://help.sbcglobal.net/dsl/speedtest/

Also on that page is this disclaimer. Read it as it's informative.

What is throughput?
Throughput is the amount of data moved successfully from one place (e.g., your computer) to another (e.g., any given website on the Internet) in a given time period.

What does this test measure?
This test measures the throughput of the connection from your computer to our network location. The throughput of your DSL Internet service is based on a number of factors, including the distance between your home/office and our network location, the number of "hops" from our network location to your computer, the performance of network servers and routers, the condition of any lines between these two points, environmental factors, and your computer performance. Because many factors affect throughput, your actual experience may vary. The results of this test could be affected by a number of factors inside your home or business, and in the network.

This test checks throughput between your computer and our network to the Internet. This test does not check sync rate (the speed or capacity of the DSL connection from the Network Interface Device at your home to the DSL Access Multiplexing or Remote Gateway equipment in our network). Only a trained technician using special equipment can test the sync rate. Throughput is not necessarily an indication of sync rate.