Congestion control in DCCP for real-time applications over satellites and long delay wireless links

Today's de facto standard transport protocol for real time applications is UDP, whichdoes not have congestion control. As TC;P is a reliable protocol it is not suited for real time applications. One of the basic objectives of formulating the Datagaram Congestion Control protocol (DCCP) was to help fight the ever existing problem of network overload for real-time applications by performing intelligent congestion control at the transport protocol level, which would be fair to co-existing TCP data streams. This problem becomes more serious and relevant ,when it comes to satellite links, where we have limited bandwidth, long delay and comparatively larger amount of transmission errors. This thesis focuses on three main things as a part of the research: first, it identifies the characteristics of DCCP over live satellite and 1011g range wireless links and evaluates their performance [l].Secondly, it proposes modifications to DCCP's existing congestion control mechanisms so that it can perform better over satellite links [2]. And finally, the thesis extends its scope to VoIP applications and proposes further modifications to improve voice quality using DCCP over satellite links [3]. All the proposals presented in this thesis were first evaluated by simulation and then by performing experiments with a DCCP network stack of a real operating system and on a live satellite link