COMMUNICATION SERVICE NETWORK AND COMMUNICATION SERVICE SYSTEM

PROBLEM TO BE SOLVED: To provide a communication service network capable of keeping a terminal number secret, while permitting an incoming call from a terminal having a trusting relationship with a user of the terminal on an incoming call side in accordance with a signal procedure and preventing an incoming call from a terminal other than that the user of the terminal on the incoming call side relies on.SOLUTION: A communication service network 20 which is connected to a plurality of terminals 10 and relays data transfer between the plurality of terminals 10 comprises a network interface part 21, an authentication part 22 and a communication acceptance part 23. The authentication part 22 authenticates the terminal 10 based on a terminal number of the terminal 10 transmitted through the network interface part 21 from the terminal 10 and a terminal number stored in the authentication part 22 beforehand. The network interface part 21 permits communication between the plurality of terminals 10 and the authentication part 22, communication between the authenticated terminals 10 and the communication acceptance part 23, and communication among the plurality of terminals 10 approved by the communication acceptance part 23.