Smart proxy: reducing latency for HTTP based Web transfers across satellite links

Abstract

Hypertext Transfer Protocol (HTTP), the prevalent application layer protocol in the Internet has had a major role in the widespread and easy access to the Internet. With the increasing amount of data transfer over the Internet, satellite links are increasingly being used for Web-transfers. Web documents such as HTML pages generally reference multiple files to display a page. HTTP gets all these documents sequentially, thus increasing latency. Due to large round trip times over satellite links, the delays become unacceptably high. The smart proxy approach uses a proxy server at both the receiver and sender side to implement parsing, caching and prefetching of referenced documents on the sender side and caching at receiver side. UDP (user datagram protocol) is used as the underlying transport layer protocol. More than three fold improvement is observed when the number of referenced files is small. We observe a further improvement with (i) an increase in the number of referenced documents and (ii) an increase in bit error rate in the satellite environment.