The user can select the mode of Username, E-Mail or Mobile number (E-Mail and Mobile number should be bound with a username). After inputting username, password and server IP address, users can click “Login” to enter the interface of conference room selection, which is user-password-authentication mode. If it is under conference-password-authentication mode, and users have the password, then users can choose “Anonymous login”. Therefore, users can login by username (discretional) only. If it is under Anonymous Login mode, to login participants need usernames (discretional) only, and they are authorized with the participant rights only. (For details, see instruction of Verification mode and user right of login underneath).