Global Proxy Configuration
AJAX Proxy Configuration.earfile that define Ajax Proxy at the level of portal. All portlets, themes, other enterprise applications can use it.
If you want to change the Global proxy configuration then you will have to change
wp_profile\installedApps\sunpa\AJAX Proxy Configuration.ear\wp.proxy.config.war\WEB-INF\proxy-config.xmland restart the Ajax Proxy Configuration application.
The actual AJax Proxy servlet is defined in
wp_profile\installedApps\sunpa\wps.ear\wps.war\WEB-INF\web.xml. By default it is configured to forward every request to /wps/proxy and /wps/myproxy to the Ajax Proxy Servlet. So if you want to support any other url mapping such as /ibm then you will have to change the web.xml file in the wps.war and redeploy it.
Application Level Proxy Configuration
You can override the proxy configuration at your application level. When you do that the proxy configuration defined in your portlet will take precedence over the global proxy. Take a look at AjaxProxySample for sample of how to configure application level proxy.
Important Note As portal server administrator you can configure portal to rule application level ajax proxy configuration by setting this property in the config service.
proxy.enforce.global.config = true