"Movement of Enhancing Opportunities and Improving Technology", abbreviated as Fatih, is among the most important educational projects in Turkey, in which students and teachers can use their tablet PCs to obtain educational data (text, images, media, etc.) stored in cloud services. However, the limited network bandwidth and increase in both the number of users and their educational data sizes degrade the system performance and even negatively affect the overall usability of the system. Using proxy server is an approach to both decreasing network traffic and increasing the efficiency in data transfers between end users and cloud services. In this approach, it is critical that when synchronization process will be performed. In this paper, bandwidth utilization, CPU and memory usage information have been examined for obtaining accurate synchronization time for this school level proxy server based distributed systems architecture. In order to minimize effect of too large and too small CPU and memory usage data, we use min-max normalization. Also, multiple linear regression is used to estimate a node's availability for communication. Experimental results show that proposed technique is feasible not only for school level proxy server based systems but also for other systems.