The use of wireless internet increased rapidly due to the wireless network technology development such as Wibro, LTE and the extension supply of wireless terminals. A special quality of wireless network that is used by many people in an Access-Point increased overhead and lowered the service quality. When we look at All-IP network realization based on a single protocol and transition of address system to IPv6, the problem becomes more serious. To address these issues, many header compression algorithms have been proposed over decades. However, the past Header compression algorithms are not suitable for the current wireless environment. The proposed ROHC has problems that an increased demand for computing power by increasing complexity of the compression algorithms. In this paper, our proposal is that we can reduce overhead and increase efficiency of network by contracting IP header through IP header translation in a gateway. In order to test this proposal, we implemented a Testbed in which we conducted the experiment in the 802.11b wireless with 11Mbps. Then we compared the results to efficiency along with IP payload size. The results shows that we can reduce the transmission delay time by 67.9% and improve network efficiency by 42.54%. In the event that this suggestion applies to IPv6, we can expect more positive effect.