Efficient and Reliable Transmission Framework over SDN

In recent years, the size of files transmitted on the Internet has become larger. Some related issues concerning about the insufficient network bandwidth are also discussed intensely. Benefiting from SDN, network bandwidth utilization could be more efficient by defining customized flow rule. Inspired from the concept, we propose a framework to improve efficiency of TCP transmission through the support of SDN. Software-Defined Network is a centralized network, while switches among SDN comply with the instructions from central controller. As a consequence, developers could define rules through controller to build a customized network with various functions and features. In addition, central controller also allows network administrators to monitor and to manage the network easily. These features make SDN widely applied in different fields. In this thesis, the main theme of our framework is to convert the TCP transmission in SDN into UDP transmission on the premise of without affecting users. The framework contains a series of functions, including packet format transformation, buffering, and retransmission on switches. That is, for users, they are transmitting data with TCP, while the overhead of TCP traffic is reduced through a reliable UDP transmission mechanism among a SDN enabled network. Also, our framework guarantees the sequentiality and reliability of packets in UDP transmission. In our implementation, we adopt Mininet to emulate the environment of SDN and use Scapy to capture, forge, and transmit packets at scenarios of different loss rates and number of switches. From the experiment results, our proposed framework presents the feasibility and effectiveness and outperform the traditional TCP transmission.