This article describes the installation process of using Azure Access Control Service (ACS) as an identity provider for SharePoint. This article uses Windows Live-ID as test.
This article uses ACS as the first federator after the consuming application with reference to the below architecture.
1: Administrative access to the Azure ACS. (https://manage.windowsazure.com/)
2: Access from SharePoint solution to Azure ACS url. (Internet browsing available)
3: Access to public URL of SharePoint solution. (SharePoint exposed to the internet)