Depending on the resources the page loaded is linked and how your connection to the internet is configured, you would hit the maximum number of connection per hosts ( and unlikely the maximum number of connection to the server ) or even the bandwidth limit in a few second of time.
Try to make your page link to less resources, consider using a CDN, or multiple host, and if you can consider using a proxy server for the classroom.
Way to reduce the number of connection to the server :
- Inline you javascript (include your JS into your HTML )
- If inlining is difficult, of scruipt are shred between page consider concatenating the shared scripts into one file
- minify you javascript
- inline your CSS ( same as above with the CSS )
- same strategies as the ones used for javascript
- reduce the number of image linked in one page
- resize you image to be of the size displayed in the page