HTML compression

You should consider HTML compression if you have users who are connected to Sterling Order Management System Software over high latency or low bandwidth network links.

HTML compression can reduce the size of the HTML pages by up to 85%.

Currently, the Sterling Order Management System Software Console UIs have been tested with F5 Big-IP v9 as an HTML compression engine.

If you were to use a Big-IP, you should be aware of the following Big-IP specific configuration requirements in the HTTP Profile configuration tab:

• You need to set the response chunking parameter to rechunk. The default is preserve. The reason is that Sterling Order Management System Software does not set the content length in the HTTP headers when sending out the response. With the default setting of preserve, the Big-IP does not attempt to compress HTML pages that do not have content lengths set. With the rechunk setting, Big-IP compresses the response chunks as they are received. More importantly, the Big-IP can forward along the compressed chunks without waiting for the entire HTML page to be compressed.
• Big-IP allows you to specify the amount of compression processing that it attempts. The setting can range from Level 1 which tries a minimal compression in favor of processing speed to Level 9 which tries to find the most compression. We found that Level 1 compression was able to get up to 85% compression and that the benefits from Level 9 undetectable. As a result, we defaulted to testing with Level 1 compression.
• We set the compression buffer size to 128KB instead of the default of 4KB. The general thought is that the buffer size should be able to store the entire compressed response in order to set the content header length. In our testing, we didn't see any appreciable differences between 4KB and 128KB. This may be due to the fact that we had already set response chunking to rechunk - as a result, the Big-IP does not have to set the content length on the compressed response. However, we were advised to set the buffer size to at least 128KB.

We recognize that there are other HTML compression technologies available including Apache deflate module and Juniper DX application acceleration devices. Please keep in mind that we have, to date, only tested against the F5 Big-IP v9.

Please also keep in mind that the compression is only certified for the Application Console. The Applications Manager and the System Management Console do not support compression. The VT220 terminal screens are small and should not require compression.