ADSL is asynchronous. The "downlink" (ie from Internet to ADSL client) is faster than the "uplink" speeds. While downlink speeds are widely advertised the uplink speeds are not. Some applications are constrained by the uplink speed, not the downlink one and when setting up "Quality of Service" the knowing the uplink speed is critical.

This is a table of speeds we have seen reported by ADSL modems:

Downlink Speed

Uplink Speed

4096 kbs

512 kbs

Note: 8 kilobit/second (kbs) = 1 kiloByte/second (kByte/sec) 1024 kilobit/second = 1 megabit/second (mbs) 8 megabits/second = 1 megaByte/second (mbs)