Abstract: An information transmission system receives, from a first communication terminal that requests for starting communication, user identification information for identifying a first user who is currently operating the first communication terminal, and transmits the user identification information of the first user to a second communication terminal, before establishing a session between the first communication terminal and the second communication terminal to start communication between the first communication terminal and the second communication terminal.

Abstract: A communication management system includes a first terminal and a second terminal. The first terminal and the second terminal are each configured to transmit and receive content data including at least video and audio data captured at a location of each of the first terminal and the second terminal. The first terminal is designated as a content delivery source and content data captured at the location of the first terminal is transmitted to the second terminal. The second terminal is restricted from transmitting content data captured at the location of the second terminal.

Abstract: A transmission system that manages sessions established among a plurality of transmission terminals. The transmission system includes a terminal information request signal transmission part that transmits, from a first transmission terminal, a terminal information request signal to request information for identifying a third transmission terminal currently establishing a session with a second transmission terminal that is designated by a user as a destination; and a display part that carries out display in such a manner that the user can determine whether to allow the third transmission terminal to establish a session with the first transmission based on information received in response to the terminal information request signal.