With the exploding penetration of the Internet, practical multimedia applications are becoming a reality in ordinary household. The Internet, however, has inherent problems to provide services with quality assurances due to its distributed "best-effort" network architecture. This calls for the use of B-ISDN (Broadband Integrated Services Digital Network) technology which has been conceived for the provision of multimedia applications in telecommunications field. This paper explains the general concept of B-ISDN and the current status of test trials using the technology.