ATM's Slow Acceptance

Although the Taiwanese believe that 1-Gb technology will push back the acceptance of asynchronous transfer mode (ATM), they are cautiously beginning to offer ATM products. D-Link is not very interested in ATM, considering it an expensive WAN interface and more of a telecommunications product than a networking product.

Ken Lu at Accton said that they will have a sample ATM backbone out at the end of the year. "For large customers, it is a good solution as a WAN backbone," he says. "ATM has some interoperability problems, though. It will take us several months to test the c ompatibility of our new ATM product with those from Digital, Cisco, etc." Network Peripherals is also working on an ATM product.

Adam Horng, sales manager for Network Peripherals, says, "We will roll out a LAN/WAN ATM product in Japan in the first quarter of 1997. It will have a 64K/155K speed that can run over standard phone lines."

CNet is the farthest along in developing and manufacturing ATM products. Since mid-1996 it has offered an ATM/ Ethernet hub. At that time, it provided this hub as an integral part of a pilot ATM project at the Hsinchu Science Based Industrial Park (SBIP), located outside Taipei.

Over a dozen of these hubs are located at the phone company's local switching office. About 100 companies at SBIP as well as Chiao Tung and Tsing Hua universities (two of Taiwan's top engineering schools) have nodes. The WAN is connected with a fiber-optic telephone cable link that has been installed in the park. Information travels across this link at 155 Mbps using an OC- 3 interface. (OC-3 stands for Optical Carrier; the "3" denotes three t imes the speed of the base 51.6-Mbps rate.)

The CN9100 is an eight-port 10 Mbps-to-ATM switching hub with a transparent asynchronous transceiver/receiver interface (TAXI). The TAXI transfers data from the ATM interface to the Ethernet interface at 100 Mbps. The eight 10-Mbps ports provide a 10-Mbps switched Ethernet interface using 15-pin attachment unit interface (AUI) connectors. Each switched port creates a separate network segment, guaranteeing dedicated bandwidth to attached devices.

Contained within the chassis of the CN9100 are four modules: CPU, ATM, Ethernet master, and Ethernet slave. This modular design allows for easy troubleshooting and field service. The CPU module contains most of the hub intelligence and serial, parallel, and configuration ports. The ATM module has the Management Integration Consortium (MIC) connector for the TAXI. The two Ethernet modules, master and slave, hold the eight Ethernet ports.

Used as a LAN-WAN interface, the CN9100 dedicates 10 Mbps to each Ethernet po rt, with local port-to-port switching performed at a wire speed of 14,880 packets per second. ATM is supported via a configurable permanent virtual circuit (PVC) and a user network interface (UNI).

Currently, CNet is marketing these hubs to two types of clients. Phone companies will use them in a way similar to that of the SBIP project. The phone company will buy the backbones, and lease their use to companies that want high-speed WAN ATM access but don't need or can't afford the cost of their own systems. The other marketing channel is made up of large organizations that have several LANs in place. These customers want to keep the LANs in touch while still having a convenient 100-Mbps "big pipe" available for videoconferencing or large database transfers.