Measuring TFRC & SCTP Performance Over AODV In MANET

This study focuses on TCP-Friendly rate control (TFRC), which is defined by IETF in RFC 5348 as and Stream Control Transmission Protocol (SCTP), which is defined by IETF in RFC 4960 as a new transport protocol. TFRC feature as fairness has attracted real time application and SCTP features also as multi-homing and multi-streaming, has attracted multimedia applications to use it as their transport protocol instead of TCP and UDP. However, the challenge faced by TFRC that is using additive increase to adjust the sending rate during periods with no congestion. This leads to short term congestion that can degrade the quality of voice applications. SCTP faced the challenge in a best-effort network. In this study, a comprehensive performance evaluation between TFRC and SCTP has been carried out. The objectives of this research are to measure the performance of both TFRC and SCTP in MANET in terms of throughput, delay and packet loss that has TFRC and SCTP with UDP traffic some times and some experiments without UDP and the nodes is in mobility positions. All experiments conducted in this research were obtained through network simulation tools using NS-2. It is expected that this study is useful for researchers in improving both TFRC and SCTP

TCP-Friendly Rate Control with Token Bucket for VoIP Congestion Control

TCP Friendly Rate Control (TFRC) is a congestion control algorithm that provides a smooth transmission rate for real-time network applications. TFRC refrains from halving the sending rate on every packet drop, instead it is adjusted as a function of the loss rate during a single round trip time. TFRC has been proven to be fair when competing with TCP flows over congested links, but it lacks quality-of-service parameters to improve the performance of real-time traffic. A problem with TFRC is that it uses additive increase to adjust the sending rate during periods with no congestion. This leads to short term congestion that can degrade the quality of voice applications. We propose two changes to TFRC that improve the performance of VoIP applications. Our implementation, TFRC with Token Bucket (TFRC-TB), uses discrete calculated bit rates based on audio codec bandwidth usage to increase the sending rate. Also, it uses a token bucket to control the sending rate during congestion periods. We have used ns2, the network simulator, to compare our implementation to TFRC in a wide range of network conditions. Our results suggest that TFRC-TB can provide a quality of service (QoS) mechanism to voice applications while competing fairly with other traffic over congested links

Chapter Networking Applications for Embedded Systems

Embedded system

3GPP QoS Model for Networks Using 3GPP QoS Classes

This draft describes an NSIS QoS Model (QOSM) based on 3GPP QoS classes and bearer service attributes. Specifically, this draftdescribes additional optional parameters for QSPEC which carries 3GPP QOSM specific information and how the QSPEC information should be processed in QNEs.\u