Performance Modeling of UDP over IP-Based Wireline and Wireless Networks

Introduction The ubiquitous nature of IP-based networks has lend credence to the volume of activities and attention accruing to it in the recent times. Driven by the ever-increasing demand for bandwidth and Quality of Service (QoS) guaranteeing, the core of today's network (either wired or wireless) has been evolving. In this research effort, the authors are interested in the behaviour and performance of User Datagram Protocol (UDP) over wired and wireless networks. UDP is an unreliable protocol because it is unidirectional unlike Transmission Control Protocol (TCP) that is connection-oriented and bi-directional in nature. According to Foster, Kesselman, and Tueke (2001), the rapid increase in network bandwidth and the emergence of new routing and switching technology has made data transfer protocols to become bottlenecks for many applications. Zhang and McLeod (2005) also admitted that the evolving nature of today's Internet has made protocols to be constantly modified in order to optimize performance. Many modifications to the existing protocols have been proposed in the literature to reduce latency. Some of them have been implemented already on the Internet like pre-fetching web pages the user is likely to access next, while browsing the current displayed page (Crovella & Bardford, 1998) and avoiding the cost of round trip time (RTT) by reducing the number of HyperText Transfer Protocol (HTTP) connections (Padmanabhan & Mogul, 1994). Motivation Connectionless Data Transfer is not widely understood as TCP/IP (which is connection-oriented data transfer), it is often difficult in the course of developing service and protocol definitions to adduce a rationale for incorporating UDP, and even more difficult to determine appropriate locations for connectionless service within the layered protocol stack. Since UDP is unidirectional as reproted by Xylomenos and Polyzoz (1999), our aim was to compile a comprehensive set of data describing the performance of UDP over wired and wireless networks in terms of packet loss analysis, bandwidth, and throughput. There is absolutely no guarantee that the datagram will be delivered to the destination host. Not only the datagram can be undelivered, but it can be delivered in an incorrect order. On the basis of the foregoing, there is the need to carry out a critical analysis of UDP/IP connection on any network; be it wireline or wireless. Related Research Network researchers have been improving UDP for many years and have published a series of UDP variations. Although TCP is still dominant in the Internet, the drawbacks inherent in its window based congestion control mechanism prevent its use in high bandwidth-delay product (BDP) environments (Gu, Hong, Mazzuco, & Grossman, 2005). According to Zhang and McLeod (2005), many modifications have been made to the existing protocols in order to reduce latency. Noghani, Kretschmann, and McLeod (2001) suggested the use of multiple TCP connections in conjunction with FTP while the NCSA ("Automatic TCP Window ...," 2005) used better estimating bandwidth-delay products by adjusting TCP parameters. However, none of the above mentioned approaches deal particularly with the bevaviour of UDP over various media. Our work will also extend the published results in Eckhardt & Steenkiste (1996) and Nguyen, Katz, Noble, and Satyanarayanan (1996). He & Gary-Chan (2004) reported that packets aggregation was previously proposed for the Internet with the objective to reduce the number of small packets, e.g., the TCP ACKs for web servers (Badrinath & Sudame, 2000), or Voice over IP (VoIP) packets ( Tounsi, Tountain, & Kamaoun, 2001). System Model In this section, we discuss the conceptual framework for the model of UDP over wired and wireless networks. We also highlighted the model parameters. The model was developed using standard simulation software called Network Simulator 2 (NS2). …