1. Go to transaction SICF then click Execute button or press F8.
2. Click "External Aliases" button.
3. Right click on "default host" then choose "Create External Alias" from the context menu.
4. Fill the "External Alias" and "Description" fields.
5. Choose the target service you want to map to this alias on tab "Trg Element". Double click on the service till the same appears in the "Trg Element" field.
6. Now you can click SAVE as all the mandatory fields have been filled. After that confirm that the alias you created exists in the node.
7. Right click on the external alias and choose "Test External Alias". Confirm that the URL can be called and after logon, the mapped service is called.