There is currently much interest in access protocols for integrated line- and packet-switched networks. A new multiple-access protocol, designed to provide fair channel access for a heterogeneous user population, has direct application to this problem. A distributed reservation scheme, incorporating both fixed-assignment and random-access techniques, controls the access to time slots of a broadcast channel. The number of slots reserved by reservation signals is a function of past channel activity. In integrated voice/data networks, users obtain synchronous transmission slots for sending packetized voice. The synchronous connection is released during silence periods, freeing the slots for data transmissions. A combination of simulation and analysis provides the throughput-delay performance of integrated voice/data neworks.