A communication management system includes a storage unit, a receiving unit, and a first transmitting unit. The storage unit stores therein: an address of a first terminal that establishes a first session with a relaying apparatus; an address of a conversion system that establishes a second session with the relaying apparatus, the conversion system mutually converting a first communication scheme and a second communication scheme; information for identifying the second terminal that establishes a third session with the conversion system; and a host name of another communication management system managing an address of the second terminal. When the receiving unit receives, from the first terminal, a request to start communication between the first terminal and the second terminal, the first transmitting unit transmits, to the relaying apparatus, the address of the first terminal, the address of the conversion system, the terminal identifying information, and the host name.