NTT and Hongkong Telecom Achieve Success in ATM^(*1)-SVC^(*2) Trial
-- ATM Technology Improves Internet Efficiency --

In the latest test of the ATM international interconnection trial that has been implemented between Japan and other destinations such as Hongkong, Thailand, Indonesia and Malaysia, NTT and Hongkong Telecom have jointly achieved success in an ATM-SVC connection trial. This marks the world's first confirmation of connection functions and operations by telecommunication carriers that assume actual applications.

ATM lines provide two types of connection patterns: dedicated connections by PVC^(*4) and connections on demand via SVC. As PVC connections can link only pre-determined destinations, multiple PVC lines must be set up to make connections with more than one destination - a pattern that all commercial international ATM services use at present.

With SVC, however, internet-like connections can be made to any destinations. The hop-by-hop transfers between each transit router required by PVC connections have been a problem up to now when sending a large volume of data via the Internet or Intranets by imposing excess loads on networks and routers. By connecting the routers nearest the sender and the destination by SVC it realizes more sophisticated and flexible connection than a method of connecting multiple routers in full-mesh configurations by PVC. This means that it is possible to reduce the load of all routers in full-mesh configurations and to use resources of ATM networks and the Internet more effectively (See Figure 1 in Attachment 1).

There still remain some issues to be solved before providing international commercial ATM service by SVC, such as establishing a uniform address structure in cooperation with international standardization organizations and telecommunication carriers in each country, installing B-ISUP^(*5) on ATM switches to be connected, and standardizing detailed functions. Accordingly, we plan to carry forward with studies aimed at providing SVC-based service in the near future by testing various connection interfaces and protocols and implementing trials with other countries.

NTT also intends to continue to actively address each project in the AMF international multimedia utilization trials in order to contribute to the development of multimedia in the Asia-Pacific region.

*1 ATM (Asynchronous Transfer Mode)
Communications technology most suitable for multimedia communications, as it supports low-speed communications such as voice as well as high-speed data communications.

*2 SVC (Switched Virtual Channel)
A communication circuit established between a sender and the destination on demand.

*3 AMF (The Asian Multimedia Forum)
An open forum for private companies and organizations established in June 1997 by NTT and 16 telecommunication carriers, etc., in the Asian region, with the objective of jointly developing, facilitating usage and structuring platforms for multimedia applications and services in the Asia-Pacific region. As of November 1998, the number of member companies and organizations exceeds 50. The AMF website is at: http://www.asiamf.org

*4 PVC (Permanent Virtual Channel)
A communication circuit established between a user and a pre-determined destination. A new PVC must be set up for communications to other than the pre-determined destination.

*5 B-ISUP (Broadband ISDN User Part)
A signaling system used between nodes as well as between networks in broadband networks.