In many computer-communication protocols, the transmission rights are circulated among the users in cyclic order for the sake of fairness. The performance of such protocols has been analyzed in terms, of multiple-queue cyclic-service models, or polling models. This paper reviews applications of the analytical results for polling models to the following communication networks: the half-duplex transmission, polling data link control, MSAP (BRAM), Newhall loop, and explicit and implicit token passing protocols. Substitution of the network parameters into the parameters of polling models is illustrated, and many numerical examples of network performance are provided. Protocol features that are difficult to incorporate into currently analyzable models are also discussed for potential future research. © 1991.