A broadband access node and method for controlling access by end users to services over communication channels. A resource admission control mechanism includes a first memory for storing information about a currently available transmission capacity on an uplink channel, a second memory for storing information about a currently available transmission capacity on a downlink subscriber line; and a third memory for storing information about a currently available maximum performance of the access node. A fourth memory stores service-related information regarding the capacity and performance service requirements of respective services. A processor calculates whether the service requirements of a requested service fulfill given conditions in relation to currently available uplink/downlink capacity and currently available performance capability of the access node. Requests that fulfill the given conditions are granted while requests that do not fulfill the conditions are rejected.