4.3. Network Bandwidth Planning

With modern switched Ethernet networks, bandwidth is rarely a factor when planning SavaPage deployments. The bandwidth consumed by SavaPage is usually dwarfed by the print document data - e.g. the PostScript and PDF spool data sent across the network. Bandwidth does however become a consideration when planning deployments crossing physical site boundaries such as networks linked via a WAN.

SavaPage uses JSON based HTTP Requests for communication between browser-to-server (Ajax) [1] and server-to-browser (Comet) [2]. This protocol is very bandwidth efficient and designed to work well on low bandwidth and high latency networks.

[1]

Ajax (an acronym for Asynchronous JavaScript and XML) is a group of techniques to create asynchronous web applications. With Ajax, web applications send data to, and retrieve data from, a server asynchronously using an XMLHttpRequest object. Despite the name, the use of XML is not needed, and JSON is often used instead. Also, requests do not need to be asynchronous.

[2]

Comet (or “Reverse Ajax”) is a web application model in which a long-held HTTP request allows a web server to push data to a browser, without the browser explicitly requesting it.