Switched arrival/server systems (SAS/SSS) are typical examples of hybrid systems which involve both continuous dynamics as well as discrete phenomena. It is known that SSS exhibits periodic behavior in asymptotic way while SAS may exhibit chaos. This paper treats SSS with three buffers where each buffer has capacity limitation. Focussing on periodic solutions with three switchings (P3), we analysed the generated periodic modes and their stabilities in detail. Finally, a control strategy for the periodic solutions P3 is proposed assuming that the capacity limits of buffers are available for control.