Packet Drop Rate and Round Trip Time Analysis of TCP Congestion Control Algorithm in a Cloud Based Collaborative Virtual Environment Abdulsalam Ya’u Gital 1,2 , Abdul Samad Ismail 1 , Haruna Chiroma 3,5 and Sanah Abdullahi Muaz 4,6 1 Department of Computer Science, Universiti Teknologi Malaysia, Malaysia 2 Mathematical Sciences Department, Abubakar Tafawa Balewa University, Bauchi, Nigeria agital@acm.org , abdsamad@utm.my 3 Department of Artificial Intelligence, 4 Department of Software Engineering, University of Malaya, Malaysia 5 Federal College of Education (Technical), Gombe, Nigeria 6 Bayero University Kano, Nigeria hchiroma@acm.org , samaaz.csc@buk.edu.ng Abstract—Collaborative Virtual Environment (CVE) has become popular in the last few years. In CVE the state of the virtual objects is witnessing rapid change. When a user performs an action in CVE, the information of the action needs to be transmitted to other users to maintain consistency in the cooperative work. Currently, in the design of most CVE systems, TCP is used for its reliability. When packet loss and round trip time are high during data transmission, it affects the performance of the CVE systems. This result to inconsistent state of virtual world even with the later retransmission of the lost packets. This paper implements a cloud based architecture for improving consistency and scalability in CVE systems proposed by Gital et al. (2014). We analyze and compares the drop rate and RTT of different TCP variants with CVE architecture. Our simulation results show that Vegas, Newreno and Reno can be promising TCP variants in the cloud based CVE systems compared to other variants. The Vegas, Newreno and Reno can effectively be used as an alternative to other variants of the TCP in efficient applications of the CVE.. Keywords— TCP Variants; Packet Drop Rates; Round Trip Time, Collaborative Virtual Enviroment; Cloud based Architectural model. I. INTRODUCTION The use of CVE applications minimizes cost of training thousand participants located in different geographical locations concurrently. The CVE allows these participants to share a common virtual environment, including virtual entities and resources maintained by a group of computers, in such a way that it can support effective communication between them to achieve synergistic coordination of tasks [1-3]. Applications of CVEs include military training, industrial remote training, Education, massively multiplayer online games, and collaborative engineering [4-7]. As the number of concurrent participants is becoming larger, data transmission alone the network may experience high packet dropt rate because of congestion and will no longer provide the level of consistency required [1, 7, 8]. The round trip time may also rise due to network congestion, that will affect the average performance of the systems and results in inconsistency situation. TCP is the widely used transport protocol that provides reliable packet delivery over an unreliable network in the current TCP/IP network. Most virtual collaborative applications have been designed with protocols that provide timing of data transmission due to the consistency requirement in the system. Users in CVE cooperate with each other and interact with the virtual environment; the state of the virtual environment is changing fast, how to transmit the interpretation of the user level interaction in the network is a challenging task. CVE is more concern about the performance of the virtual world. Consistency is more critical since high drop rate may lead to very poor state of the virtual world at each terminal. With the increasing speed of network and readily available internet, bandwidth is no longer a limiting factor in the internet. CVE application today are built over TCP, because TCP provides sequence deliverance of data and unfailing data transmission among communicating nodes. One of the strengths of TCP is its high responsiveness toward network congestion. TCP is also a defensive protocol as it detects incident congestion as its result to try and lessen the impacts of the congestion by preventing the collapse of communication [9]. The TCP focuses on reliability, stability, and correctness of data transfer which fits well with requirements of loss sensitive applications such as web browsing and file transfer and left with the problem of delay due to high drop rate in CVE applications. Packet loss in a network affects the quality of service 2014 UKSim-AMSS 8th European Modelling Symposium 978-1-4799-7412-2/14 $31.00 © 2014 IEEE DOI 10.1109/EMS.2014.32 442