An apparatus and mechanism to subscribe to a single address and or session management service from multiple devices (such as e.g. tablets, smart phones, netbooks or other types of communication terminals or client devices) with a single account and password through the automatic assignment of a dynamic opaque SIP service profile to each device a user uses to signin to the service. After sign-in transparent call management services are provided to the user and allow the user to control sessions on any signed-in device from any signed-in device without revealing the distinct dynamic opaque SIP service profiles to the user.