Ajax is intertwined with the network, so bad code is going to mean lots of troubleshooting by network administrators, as well as developers: The bottom line is to encourage good, network-aware coding! The same organizational "rules and tools" -- coding standards, testing regimes and source-code control — that are in place for other languages must be applied to JavaScript to ensure that Ajax applications are supportable and robust.

3) XML is not required

Despite the "x" in the acronym, Ajax does not require XML. The XMLHttpRequest object can transport any arbitrary text format. For many Ajax developers, JavaScript Object Notation or even raw JavaScript code fragments make more sense as a data format, given that JavaScript is the consuming environment. For direct input into documents, other developers may favor raw text or HTML fragments. Still others will use such data formats as the less-known YAML markup language or such old standbys as comma-separated values.

Of course, it is possible and certainly reasonable to use XML, but it is far from required. Using binary formats for uploading files is not supported yet by the XMLHttpRequest object, but considering that Flash uses a binary format called Action Message Format, it is likely that similar features will be found in Ajax applications soon enough. You should know which format is being passed around the network, because it isn't always XML. Also, make sure you can analyze the format for performance and security.

4) Plan for an increase in HTTP requests

The most obvious issue for the network administrator supporting Ajax applications is that the architectural programming pattern has changed the network utilization of Web applications from a batch-like, somewhat infrequent response of a few hundred kilobytes, to a more continuous exchange of smaller HTTP responses. This means that network-bound Web and application servers may find themselves even busier than before. What Ajax will do to your server and network utilization certainly will depend on how the application is built — make sure your developers understand the network impact of their applications.

5) Optimize Ajax requests carefully

Web applications should adhere to the network delivery principle of sending less data, less often. That doesn't mean that this principle is widely followed by developers, however. Fortunately for the network, HTTP compression of Ajax responses can reduce response size and is supported in all modern browsers. Because of dynamic compression's overhead, however, speed may not improve much if responses are indeed relatively small. This means that it would be wise for network administrators to turn on compression on their Web server, but they need to understand that with Ajax applications, their gains won't be as big as with traditional Web applications.