Research And Implementation Of Prioritized SCTP Streams

With the steady improvement of hardware technology and network communication technology, end users are accustomed to obtaining the multimedia network services through the Internet, like Web browsing, instant messaging, video chat etc. However, these services are often bandwidth-intensive, and needed to get various data from server in a single service. However, the network couldn't provide enough bandwidth for all kinds of data in the case of low bandwidth, so the network server need a way to transmit multiple data in parallel, which also effectively respond to periods of insufficient bandwidth.SCTP is a reliable, connection-orientied transport protocol. Its multihoming and multistreaming are very suitable for these types of multimedia network services. Based on the analysis of the source code of SCTP in Linux kernel, this paper purposes an optimization to SCTP for high data transfer delay in periods of low bandwidth available, and implement it. Based on the multistreaming of SCTP, the scheme assign a priority value to each logical stream in SCPT association, and then put the data of prioritized logical stream to corresponding prioritized output queue. Finally, we schedule these queues with scheduling algorithms, which could ensure the transmission of the more important data with lower delay when low bandwidth is available. In order to meet the different requirements of applications for prioritized SCTP streams, the paper implement two optional scheduling algorithm: prioritized queue scheduling and weighted queue algorithm.In order to verify the effectiveness and feasibility of the scheme, this paper also implement a kind of Web browsing service based on prioritized SCTP streams. For that, I did two job. Fist of all, I modified the soure code of Apache and Firefox to let them communicate with each other in SCTP, and use multithreading to improve the performance of Web browsing based on SCTP. The first job successfully avoid HOL, SYN flooding attack in traditional TCP-based Web browsing. Secondly, I design and implement a scheme to using prioritized SCTP streams for Web browsing. Howerve the multithreading Web browsing based on SCTP will cause data interleaving, which could delay of user waiting when low end-to-end bandwidth available. The second job decrease the delay of user waiting in data leaving.