Presence information

Presence information is in electronic telecommunications, the information includes the ability and willingness of a potential communication partner ( for example, another user on a call). The client of a user of its status propagates to a presence server that manages this and optionally reproduced.

Presence information is an important part and the most important innovators of today's instant messaging and VoIP services.

Presence status

The client a user can publish a presence state to publish the current communication status of the user. This status information other publication which communicate with the user to communicate via its availability and readiness. Nowadays, the presence status is most often displayed as a small icon in instant messenger clients, usually different icons for different status.

Also, the dial tone in combination with the busy tone in the classic telephone network is actually a presence status if it is not mentioned in this context.

Usual status variants that are found in almost every instant messaging client that are " For Chat Available", "Present", " Absent", "Busy ", "Please do not disturb". In addition, additional attributes such as mood, residence or free text fields in some Instant Messenger clients are available.

Privacy

Presence information is extremely delicate and in real systems, it would be appropriate to limit the presence information to a closed user group. Outside of working hours it is so for example interest to employees, not to inform his colleagues about everything. A minimal version of this is already implemented in many instant messaging programs, and manifests itself in the "Invisible " status, which is visible only for certain selected contacts.