The Communication Processing Systems(CPS) is a gateway that supports 01410 hitel service by connecting the public switched telephone network(PSTN) with the public switched data network(PSDN). The CPS is made the meausred rate accounting method for the biling after extracting the originating numbers from the nearest local PSTN. In this paper, a numerical simulation is carried out on the offered traffic per user on the telephone access part of the CPS according to change of call loss probability and also propose the proper number of channels based on the simulation results.