Congestion Control Enabled VoIP by Flexible Bit-rate

• Main Authors: Ting, Yu Chi, 丁諭祺
• Other Authors: Lien, Yao Nan
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/96jkue

碩士 === 國立政治大學 === 資訊科學學系 === 99 === With congestion-control ability, Datagram Congestion Control Protocol (DCCP) is expected to replace UDP as a mainstream unreliable transport protocol. But our study found that DCCP is not able to get a fair share of bandwidth under the competition of others transport protocols no matter in NS-2 simulation or real world networking environments. Furthermore, any congestion control protocol that postpones the transmission of packets may not be adequate to support time-sensitive network services. To maintain the quality of time-sensitive network services as well as to be TCP-friendly when facing network bandwidth fluctuation, we propose a Flexible Bit-rate congestion control mechanism for VoIP to adjust their data rate. Our experiments show that Flexible Bit-rate congestion control method could effectively reduce the packet loss rate and to maintain VoIP quality as compared with UDP and DCCP. Furthermore, it can have a much better bandwidth efficiency and adjust better to network fluctuation.