Methods and apparatuses to provide services to people who wish to make connections for real time communication, such as live telephone conversation, chat, video conferencing, etc. In one embodiment, a method includes: receiving in a system a call back time window for a request from a first entity to establish a media connection for real time communication with a second entity, the call back time window being specified by the first entity to indicate a period of time including a current time during which the first entity is available for real time communication with the second entity; and attempting to establish the media connection between the first entity and the second entity according to the call back time window.