H04L67/00
Network arrangements or protocols for supporting network services or applications
H04L67/00
Network arrangements or protocols for supporting network services or applications
H04L67/54
Presence management, e.g. monitoring or registration for receipt of user log-on information, or the connection status of the users
H04L67/54
Presence management, e.g. monitoring or registration for receipt of user log-on information, or the connection status of the users