| Today, the most important transport protocol in the Internet is the Transmission Control Protocol (TCP). Therefore, different implementations of it have been introduced. New-Reno and Vegas are two variants of TCP. Besides improving TCP, it is important to improve the performance of routers as well. Therefore, efforts have also been made to provide routers with active queue management and even enable them to inform the TCP senders about developing congestion (i.e. explicit congestion notification). One of the active queue management techniques is Random Early Detection (RED). Also, routers can use Backward Explicit Congestion Notification (BECK) to notify TCP senders of developing congestion.; In this research, the BECN option is enabled for TCP New-Reno flows and then the performance of this combination is compared with that of TCP Vegas. In all the cases, the bottleneck router is RED-capable. The comparisons are made for connections with equal and unequal Round Trip Times (RTTs), in environments that can be homogeneous or heterogeneous. Also, two different types of traffic, File Transport Protocol (FTP) and web are analyzed in the experiments. Finally, a modification is introduced to improve the fairness of New-Reno + BECN when long and short connections coexist. |
