Understanding the object retrieval dependence of Web page access

We propose a chunk-level client's latency dependence model (C-LDM) to describe the effect of network protocol, streaming data transfer mechanism, and Web page structure on the latency perceived by a Web client. Object retrieval latency is made up of four components: (i) definition - finding the definition of embedded objects in a page; (ii) queuing - waiting for object request dissemination into the network once its existence is defined; (iii) connection - setting up a network connection for data transfer; (iv) chunk transfer - transferring actual data from server to client once the connection is setup. We show that for typical network connectivity, a user's perceived page latency is mainly due to the definition and queuing of embedded object requests inside a Web page, which are related to the content structure of a Web page and the parallelism width of the browser for object fetching. Such understanding is important because it opens opportunities to improve the retrieval speed of Web surfing through the minimization of data chunk dependence.