DSLAM: DSL Access Multiplexor

All DSL lines are wired up to a DSLAM that is either located in your central office, or on a remote DSLAM that is somewhere between your home and your central office. A DSLAM is nothing more than a bank of DSL modems (anywhere from 8 to several hundred). The uplink of the DSLAM is typically a high-speed ATM interface (e.g. DS3-45Mbps, OC3-155Mbps, etc..). Remote DSLAM uplinks are typically DS3 or T1 (1.5Mbps), or multiple T1 (3.0-6.0Mbps).

It it cricital to understand that DSL protocols only operate between your ADSL modem and the DSLAM. All communication past the DSLAM (toward the ISP) is pure ATM.