In an ATM network, there are many kinds of calls which require various
qualities. A method is required to control the connection and cell ad
ministration according to the required Quality of Service (QoS) for ea
ch connection. In this paper, we propose the Quality Control Path (QCP
) concept to control the qualities of the established connections in t
he ATM switch. With this method, the buffers and the capacities of the
physical links in the switch are each divided into logical paths. We
also described a control scheme to maintain a required QoS for each co
nnection.