We have an application called EasyVista from Staff&line. It is based on Apache, PHP, MS SQL. In our configuration it uses NTLM user authentication and Single Sign On (SSO). The average performance on 256K link was about 40 seconds to open first page.
To improve performance following change were implemented:
1) Enable compression in PHP.ini
2) Enable deflate module in Apache for all JS, CSS, HTML files
3) Expire module enabled
4) NTLM Authentication disabled for all images, JS and CSS using FilesMatch
5) WAN priority increased for this server
As the result with most of the pictures and Js in cache, the main page opens in 3 seconds over 256K link.