A method of operating an access network (19, 20, 30) including a plurality of data connections (10, 19, 20) between end user devices and an aggregation transceiver device where the data connections (10, 19, 20) are aggregated for onward connection through the access network, the method comprising: storing a plurality of different profiles, each of which specifies a set of values for a plurality of parameters associated with each data connection (10, 19, 20); and, for each data connection (10, 19, 20), monitoring the performance of the data connection (10, 19, 20); selecting one of said stored profiles to be applied to the data connection (10, 19, 20) in dependence on the results of monitoring the data connection (10, 19, 20); and applying the selected profile to the data connection (10, 19, 20); wherein monitoring the data connection (10, 19, 20) includes estimating the number of times that the data connection (10, 19, 20) resynchronises, within a given period of time, as a result of an automatic or forced resynchronisation rather than as a result of user action, and using the estimated number of automatic or forced resynchronisations, when selecting a profile to apply to the data connection (10, 19, 20), the method being characterised in that estimating the number of times that the data connection (10, 19, 20) resynchronizes automatically or forcedly comprises determining the total number of resynchronisations, within the given period of time, for all reasons, estimating the total number of those resynchronisations caused by a user and subtracting this estimated number of user caused resynchronisations to obtain an estimate for the number of automatic or forced resynchronisations, wherein estimating the total number of resynchronisations caused by a user comprises detecting that more than a predetermined minimum period of time prior to a resynchronisation has elapsed without connectivity having been established and without the connection (10, 19, 20) automatically attempting, but failing, to re-establish connectivity. storing a plurality of different profiles, each of which specifies a set of values for a plurality of parameters associated with each data connection (10, 19, 20); and, for each data connection (10, 19, 20), monitoring the performance of the data connection (10, 19, 20); selecting one of said stored profiles to be applied to the data connection (10, 19, 20) in dependence on the results of monitoring the data connection (10, 19, 20); and applying the selected profile to the data connection (10, 19, 20); wherein monitoring the data connection (10, 19, 20) includes estimating the number of times that the data connection (10, 19, 20) resynchronises, within a given period of time, as a result of an automatic or forced resynchronisation rather than as a result of user action, and using the estimated number of automatic or forced resynchronisations, when selecting a profile to apply to the data connection (10, 19, 20), the method being characterised in that estimating the number of times that the data connection (10, 19, 20) resynchronizes automatically or forcedly comprises determining the total number of resynchronisations, within the given period of time, for all reasons, estimating the total number of those resynchronisations caused by a user and subtracting this estimated number of user caused resynchronisations to obtain an estimate for the number of automatic or forced resynchronisations, wherein estimating the total number of resynchronisations caused by a user comprises detecting that more than a predetermined minimum period of time prior to a resynchronisation has elapsed without connectivity having been established and without the connection (10, 19, 20) automatically attempting, but failing, to re-establish connectivity.