Patent ID: 8625620

Claim:
A communication system providing a multimedia service which enables requesting a communication network to cancel a registration for a calling terminal as a bad terminal in the communication network, wherein: the calling terminal is connected to a calling-side communication network; if the calling terminal is registered as a bad terminal in a called-side communication network, the calling-side communication network requests the called-side communication network to cancel the registration; and the calling-side communication network includes: an access request transfer device that transfers an access request, which has been sent from the calling terminal, to the called-side communication network; an access request cancel notice receiving device that receives an access request cancel notice, which indicates cancellation of the access request, from the called-side communication network; an access-disable terminal information registering device that registers in an access-disable terminal storage device, based on the received access request cancel notice, identification information of the calling terminal which sent the access request and identification information of the called-side communication network which sent the access request cancel notice, which are associated with each other in the registration; a terminal safety verifying device that verifies safety of the calling terminal; and an access rejection cancel request sending device that sends an access rejection cancel request to the called-side communication network when it is determined in the safety verification that the calling terminal satisfies the safety, where the access rejection cancel request contains the identification information of the calling terminal, and is sent by using the identification information of the called-side communication network which has been registered in the access-disable terminal storage device in association with the identification information of the calling terminal.