Abstract- Computer network reliability is one of the important factor in data communication process. To build a reliable computer network, required capability of link or path to transmit the data from source to destination device. This is suitable with the challenges of future computer networks, where link or path is not be a problem in transsmiting data over computer network. TCP/IP as on of the network protocol that is used on today Internet have been able in connecting network devices around the world. But, in some environment, TCP/IP protocol have some of weakness, there are intermittent connectivity, long or variable delay, asymmetric data rate and high error rate. On the other hand, the emergence of Delay Tolerant Networks (DTN) protocol present to overcome that problem by giving a solution in improving reliability of computer network. DTN support communication process between node that are connected intermittently by isolating delay using store and foreard technique. This research aims to comparing the performance of TCP/IP and DTN protocol on unbranched network. Performance testing on each protocol will be done on intermittent connectivity environment and non-intermittent connectivity environment by using some of this following parameter, delay, throughput and the successful of data delivery. In non-intermittent environment, can be concluded that TCP/IP has better performance based on delay. Based on through TCP/IP has better performance for particular file size and DTN has better performance for particular file size and DTN has better performance for others file size.