- RAD's ACE-2002 multiservice access concentrator and ATM network termination unit defines the demarcation point between the networks of Japan Telecom and its subsidiaries, enabling Japan Telecom to control, manage and shape the traffic flow between them.

Benefits

- Supports ATM OAM protocols

- Monitors, shapes and polices traffic

- Provides physical SONET protection

Major Japanese carrier Japan Telecom is focusing on providing its customers with fully integrated international and domestic services. To this end, it has established various subsidiaries to provide a broad range of global and mobile voice and data communications.

Although the subsidiaries have set up networks of their own, they still, at some point in the network, send traffic over the infrastructure of their parent company. The cellular subsidiary J-Phone, for example, aggregates traffic from several base stations onto a single ATM link and runs it to its base station controller over the ATM infrastructure of Japan Telecom. Japan Telecom's ATM infrastructure will be able to handle the future broadband 3G services that J-Phone plans to offer, in addition to current 2G/2.5G services.

Manage Traffic between Networks

Japan Telecom uses RAD's ACE-2002 multiservice access concentrator and ATM network termination unit to define the demarcation point between the two networks and to control and manage the traffic flow between them. It allows Japan Telecom to police and shape the traffic coming from J-Phone, while assuring J-Phone that it is receiving the requisite service from Japan Telecom, as stipulated in their service level agreement (SLA).

"Japan Telecom selected the ACE-2002 due to its good experience with RAD's ACE-101, which guarantees Quality of Service in its leased line ATM service," says Mr. Maeda of ITFOR, the system integrator for the project. (See the article Japan Telecom Chooses RAD's ACE-101 NTU for Its MegaLaser Express ATM Leased Line Service, DataFlow, Spring 2000).

"The ACE-2002 is a high quality product," says Mr. Masakatsu Nunokawa, Manager of the ATM/Frame Relay Engineering Group at Japan Telecom. "There is no other product that provides ATM protocols such as OAM (operation, administration and management) as well as physical SONET protection in the same device," he states.

Extra Protection

RAD engineers worked around the clock to implement special features for Japan Telecom within a tight deadline. Specifically, Japan Telecom wanted RAD to develop particular hardware and fiber protection in addition to line redundancy, which automatically switches communications to a backup fiber optic link if the main link fails.

Hardware redundancy is carried out by connecting one switch port to two ACE-2002 ports using a Y-cable. In case of a hardware problem in the first module or on part of the fiber link, the ACE-2002 automatically switches communications to the backup port. The Y-cables also save Japan Telecom costly ports on the switch. "We experienced good cooperation from RAD engineers, who implemented all our requests to our satisfaction," concludes Nunokawa.

RAD has recently developed the ACE-202, a more robust version of the ACE-101.

Japanese Carrier Uses RAD Equipment to Guarantee Quality of Service

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