offline page can be achieved using following techniques -
 1.URL Redirect
 2.using web.config / .htaccess file
 3.using default.htm
 4.Siebel offline page using IIS URL Rewrite module
 
To host the offline page in Siebel during the application maintenance window, follow the below steps.
1. Create a new html file with the message you want to show when the Siebel is servers are down.
2. Rename the default.htm to orginal_default.htm in C:\ sia81\SWEApp\PUBLIC\enu
3. Copy the new htm offline page to C:\ sia81\SWEApp\PUBLIC\enu\default.htm
When you go to the application URL you will see the offline page
http://localhost/callcenter_enu
To bring back the normal Siebel screen, replace the default.htm with original default.htm file.
Siebel web server uses the default.htm as the entry point into the application. This file contains a function called GotoUrl(url), when you change the default.htm with offline page it displays the offline page.
function GotoUrl(url)
{
// Append the current hostname to the server request so that the server has
// the top level host name. This is needed to support reverse proxy servers.
url += "&SWEHo=" + this.location.hostname;
this.location = unescape(this.location.pathname) + url;
}
GotoUrl('start.swe?SWECmd=Start');
To host the offline page in Siebel during the application maintenance window, follow the below steps. 1. Create a new html file with the message you want to show when the Siebel is servers are down. 2. Rename the default.htm to orginal_default.htm in C:\ sia81\SWEApp\PUBLIC\enu 3. Copy the new htm offline page to C:\ sia81\SWEApp\PUBLIC\enu\default.htm When you go to the application URL you will see the offline page http://localhost/callcenter_enu To bring back the normal Siebel screen, replace the default.htm with original default.htm file. Siebel web server uses the default.htm as the entry point into the application. This file contains a function called GotoUrl(url), when you change the default.htm with offline page it displays the offline page. function GotoUrl(url) { // Append the current hostname to the server request so that the server has // the top level host name. This is needed to support reverse proxy servers. url += "&SWEHo=" + this.location.hostname; this.location = unescape(this.location.pathname) + url; } GotoUrl('start.swe?SWECmd=Start');