| User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) are core data transport protocols that operate on top of the base Internet Protocol (IP). Where TCP offers reliable point-to-point messaging and preserves message order even for large messages, UDP does not make these guarantees but is intended as a very fast way to send short messages. UDP is used to transport messages in many kinds of applications including system management, Voice over IP, gaming, instant messaging, e-mail delivery (on some cell phones), and RFID applications. Since UDP is an unreliable protocol that can drop the datagram packets over the network, especially in wireless or heavily loaded networks, these applications often lose crucial information which can noticeably degrade performance or result in erratic and erroneous behavior of the applications.; This thesis explores a Reliable UDP protocol for significantly increasing UDP reliability (implemented in Java as a ReliableDatagramSocket class), using a point-to-point architecture, permitting distributed applications to send and receive UDP packets much more reliably through the Internet. Experiments were conducted to measure and compare UDP and Reliable UDP statistics over wireless networks using the normal java.net.DatagramSocket class and our ReliableDatagramSocket subclass. With low overhead, Reliable-UDP compares favorably performing very reliably over networks where UDP alone degrades quickly. Reliable UDP is demonstrated within the University of Arkansas TagCentric RFID Middleware application. |
