With the expansion of Internet, the current protocol address space Internet Protocol version 4 (IPv4) is faced with a shortage and the new generation IPv6 is raised in order to solve this problem. Also with increasing interest of users in real-time and multimedia applications, the Internet and how to implement these applications to improve the Quality of Service (QoS) has become a significant challenge. In this paper, a network with both IPv4 and IPv6 protocols is simulated by using OPNET modeler and implementation of QoS is tested on it.