The present invention is directed to a scheduling method for processing at least two channels in a VoP (Voice over Packet) system. The VoP system according to the present invention includes a packet buffer for temporarily storing packets transferred from a packet network; a DSP (Digital Signal Processor) for processing algorithm modules of at least two channels; a scheduler for scheduling a channel to be executed by the DSP every cycle, and controlling the DSP to execute an algorithm module having a fixed execution time among the algorithm modules of the channels, and then an algorithm module having a variable execution time; and a TDM (Time Division Multiplexing) buffer for input/output to/from the TDM network.