A management device is used in an access network including a plurality of data connections between end user devices and an aggregation transceiver device where the connections are aggregated for onward connection through the access network. The access network stores a plurality of different profiles, each of which specifies a set of values for a plurality of parameters associated with each data connection. The device applies one of the stored profiles to each connection, and receives a notification in the event of one of a predetermined set of notifiable events occurring on the connection. It is determined if more than a predetermined number of notifications are received within a predetermined period for a respective connection and, in the event of such a determination being made, a different one of the profiles is caused to be applied to the connection.