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ISBN: 978-972-8939-25-0 © 2010 IADISAlthough CUBIC has also achieved better results when compared with CTCP, the predominance ofCUBIC was inconstant, as shown in Figure 6 and Figure 7. Window size chart shows a significant alternationamong protocols, with CTCP window growth performing better in the end of simulation time. Similarly, after450 s, CTCP senders perform better throughput and, specifically for sender37, with higher instant throughputthen CUBIC sender nodes, in the end of simulation time.4. CONCLUSIONIn this work, we have conducted a performance comparison of two variants of DCCP (CCID2 and CCID3),CTCP and CUBIC with VoIP and CBR traffic patterns. The four protocols have different approaches forcongestion control, and both traffic patterns impact protocols’ behavior in a different way.The results have pointed to a much better throughput of CUBIC in mostly CBR simulations and to abetter delay, fairness and throughput stability of DCCP CCID3, using both traffic patterns. Results haveshown that DCCP CCID3 adopts a conservative window increase algorithm.The throughput performance of CUBIC was dramatically reduced when using VoIP traffic, due to thecharacteristics of ON/OFF intervals which impact in the packet transmission pattern. DCCP CCID2 andCTCP have achieved intermediate results and they were less susceptible to the adopted traffic pattern. DCCPCCID2 has achieved better results when using CBR and CTCP has achieved better results when using VoIP.This work points to new investigation paths, as follows. The traffic pattern has shown a significant impactin the protocol behavior, hence new patterns may be tested (e.g., real-time multimedia streaming, interactivevideo). The impact of constant disconnections, as in mobile ad hoc networks, should be investigated. Finally,we intend to investigate the impact of network infrastructures with large delays, as satellite networks.REFERENCESBhatti, S. and Bateman, M., 2009. Transport Protocol Throughput Fairness. Journal of Networks, Vol. 4, No. 9, 881-894.Bhatti, S. et al, 2008. Revisiting inter-flow fairness. Proceedings of International Conference on BroadbandCommunications, Networks and Systems. London, United Kingdom, pp 585-592.Bouras, C. et al 2007. Enhancing ns-2 with DiffServ QoS features. Spring Simulaiton Multiconference - Volume 1. SpringSimulation Multiconference. Society for Computer Simulation International, San Diego, CA, 117-124.Fall, K. and Varadhan, K., 2007. The network simulator ns-2: Documentation. Available athttp://www.isi.edu/nsnam/ns/ns-documentation.html.Floyd, S. and Kohler, E., 2006. Profile for Datagram Congestion Control Protocol (DCCP) Congestion Control ID 2:TCP-like Congestion Control. RFC 4341. Available at http://www.ietf.org/rfc/rfc4341.txt.Floyd, S., Kohler, E., Padhye, J., 2006. Profile for Datagram Congestion Control Protocol (DCCP) Congestion ID 3:TCP-Friendly Rate Control (TFRC). RFC 4342. Available at http://www.ietf.org/rfc/rfc4342.txt.Floyd, S. and Kohler, E., 2009. Profile for Datagram Congestion Control Protocol (DCCP) Congestion ID 4: TCP-Friendly Rate Control for Small Packets (TFRC-SP). RFC 5622. Available at http://www.ietf.org/rfc/rfc5622.txt.Ha, S., Rhee, I., Xu, L., 2005. CUBIC: A new TCP-Friendly high-speed TCP variant. In Third International Workshopon Protocols for Fast Long-Distance Networks.ITU-T Recommendation P.59, 1993. Telephone Transmission Quality Objective Measuring Apparatus: Artificial.Available in http://www.itu.int/rec/T-REC-P.59-199303-IKohler, E., Handley, M., Floyd, S., 2006. Datagram Congestion Control Protocol (DCCP). RFC 4340. Available inhttp://www.ietf.org/rfc/rfc4340.txt, updated by RFCs 5595, 5596.Mattsson, N.-E. 2004. A dccp module for ns-2. Master’s thesis, Luleå Tekniska Universitet.Sridharan, M., Bansal, D., Thaler, D. 2006. Compound TCP: A New TCP Congestion Control for High-Speed and LongDistance Networks. Internet Draft, version 02. URL http://tools.ietf.org/html/draft-sridharan-tcpm-ctcp-02.Tan, K. et al, 2006. A Compound TCP approach for high-speed and long distance networks. Proceedings IEEEINFOCOM 2006, Barcelona, Spain.Xu, L. et al, 2004. Binary increase congestion control for fast long-distance networks. In Proceedings of IEEEINFOCOM, Hong Kong, Korea.218