Is the following configuration correct ?
If not, is there any alternative ?
<VirtualHost 192.168.1.20:80> ServerName mywebsite.fr ServerAlias test.mywebsite.fr Timeout 3000 # Overrides main configuration </VirtualHost>
Take a look at http://httpd.apache.org/docs/2.2/mod/quickreference.html
Third column on that page will tell you whether the setting(directive) you are trying to change can be specified in virtualhost or its global directive.