http://www.kitz.co.uk/adsl/DLM_system.htmThe DSLAM holds your line profile, and the sync process works to those settings. It also holds the statistics, in the same way we see in the modem.
Outside the DSLAM will be a part of the OSS system (operation support system) called an element manager. It knows how to write line profiles into the DSLAM (probably a MIB using SNMP) and how to read the statistics. This element manager is remote, but I don't know how many there will be across the country.
DLM is also a centralised process, running in a "RAMBO" box. It analyses the statistics pulled by the element manager, and follows its rules on adapting your line profile ... writing a change back via the element manager.
Nowadays, DLM will also extract that CPE information to place limitations on the allowable line profiles - almost certainly via the element manager too. We don't know how it extracts DSLAM limitation data though ... and I'm prepared to believe it wasn't coded to cope with a PCP with multiple DSLAM types.