International Journal of Computer Theory and Engineering

Abstract

Applications like streaming audio, Internet telephony and multi-player online games prefer timeliness in packet delivery to reliability. TCP’s reliability through packet retransmission and abrupt rate control features are unsuitable for these applications. As a result, these applications prefer UDP as the transport layer protocol. UDP does not have any congestion control mechanism which is vital for the overall stability of the Internet. For this reason, a new transport layer protocol--Datagram Congestion Control Protocol (DCCP) has been introduced by the Internet Engineering Task Force (IETF). DCCP is suitable for these applications because of its exclusive characteristics. It can be useful for those applications which need a session and congestion control unlike UDP and do not need reliability or retransmission like TCP. However, since DCCP is a new protocol, its performance for these applications has to be analyzed thoroughly before it emerges as a de facto transport protocol for these applications. This paper describes the basic principle of DCCP, its congestion control mechanism and measures the performance of DCCP. The results show that DCCP provides better performance for those applications that suffers the tradeoff between delay and in-order delivery.