A performance analysis of page and object retrieval using HTTP-MPLEX in symmetric network environments

HTTP-MPLEX is a header compression and response encoding scheme for HTTP. It is designed to compress traditional HTTP requests and multiplex any number of responses to a single stream, thus improving application use of TCP, reducing the number of competing parallel connections and improving the time required to retrieve responses from a server. HTTP 1.1 is limited to transmitting one response per connection, HTTP-MPLEX enables many responses to be transmitted at the same time via a single TCP connection. To analyse the effect of HTTP-MPLEX request compression and focus on the effectiveness of response multiplexing in a symmetric network environment, a client and server was written in C++ with plug-in versions of HTTP 1.1 and HTTP-MPLEX engines. This paper is a performance evaluation of our hypertext transfer engines using the simulated network environment ns (2.29-snapshot-20050921), a high- bandwidth symmetric network and a dial-up connection. An analysis of the HTTP-MPLEX response encoding scheme comparing the metrics of response time, header retrieval time and total object transfer time is given. Snap-shots of www.cnn.com, www.whitehouse.gov, www.latrobe.edu.au and a photo gallery of forty eight tiles are used in experimentation as sample web pages to retrieve using the hypertext transfer engines.