Voice over Internet Protocol (VOIP), a new promising technology which is considered as a technique for transferring audio (analog signal) over the Internet using Internet Protocol (IP), is a sensitive to delays and need a real-time priority transmission. In this paper, VOIP traffic performance is investigated using the buffer management algorithm and the proposed algorithm is compared with the VOIP standard algorithm in terms of QOS parameters (delay, packet delivery ratio, throughput, average used steps and packet loss). NS-2 Simulator is used for analysis of QOS parameters. The simulation results showed that using a certain buffer management, the VOIP performance can be improved and QOS parameters have been upgraded.
