Virtual Private Network (VPN) is a private computer network that runs over the pubic computer network or internet.VPN is implemented to overcome the security problem in transfering data using public computer network. implementing this security, of course, will decrease the data transfer performance because of encapsulation process and header overhead. To improve the performance, researcher tries to compress the header of packet in order shrink the header of packets. The header compression is also offered by mikrotic router. This paper tries to reveal the header compression capability of mikrotik router in order to increase the data transfer rate of VPN. Based on the experiment in isolated environment, it can be concluded that the header compression in mikrotik router is not capable significantly to increase the data transfer ate of VPN. Keywords: Header Compression, VPN, Network Performance