Distributed computing system is heterogeneous in nature. A computer program that runs on distributed system is known distributed program. There are a number of basic problems that likely to amplify the conceptual distance and complicate the design. There are many design issues in distributed computing systems. In this paper, the authors have discussed various issues of distributed computing system. The main focus is on the mobility of the node. At the end, they have proposed methodology to overcome mobility problem based upon pong messages.