A high performance integrated voice/data (IVD) protocol for token ring networks that operates over a wide range of data traffic levels is developed and analyzed in this dissertation;The problems raised by integrating voice/data in local area networks are identified. These problems include variable network access delay and end-to-end delay limit of voice packets, and queueing delay of data packets;In the design of the IVD protocol, a packet format is selected, conditions for selecting network parameters are derived, and a channel allocation strategy is described to provide high quality of voice over a wide range of data traffic levels while preserving satisfactory data performance;The implementation issues, specification, and operation of the proposed protocol are described based on the standard IEEE 802.5 token ring protocol. The implementation issues are studied for two principal purposes: not to modify the operating data protocol and to utilize the bandwidth for data packets when voice stations are idle. A state transition diagram is used to specify the proposed protocol;A discrete-event model of the proposed IVD protocol is developed for the accurate performance evaluation of data and real-time voice traffic. In modeling the protocol, all the necessary information which affects the state of the system are considered including location of stations;The voice/data performance of the proposed IVD token ring protocol is evaluated and the effects of voice on data and vice versa are studied. The proposed protocol provides high quality of voice without a large degradation on the data performance over a wide range of data loads.