Osicom and Fore Establish DWDM and ATM Compatibility

By: Erik Kreifeldt

In a new attempt at driving metropolitan applications of dense wavelength division multiplexing (DWDM) systems, Osicom Technologies Inc. and Fore Systems Inc. have agreed upon mutual wavelengths from the ITU grid to connect ATM directly to DWDM without using SONET interfaces—not to mention SONET add/drop multiplexers.

Using an imbedded WDM module, Fore's ASX-4000 ATM switch will fill from one to four channels of Osicom's GigaMux DWDM system with 2.5 Gbps line rates, yielding a 10 Gbps channelized throughput from the ATM box. "We're essentially taking a wavelength off of a small, passive unit [and putting it] into our active GigaMux," explains Ivo Lekich, Osicom's VP for strategic alliances.

The direct connection with agreed-upon wavelengths circumvents the need for DWDM transponders a mutual SONET interface between the DWDM system and ATM switch. Although the configuration sacrifices the standard interface, it's more cost-effective than converting the ATM signal to SONET, then passing it off to a transponder that converts the signal into a DWDM wavelength, says Robert Lamb, director of Fore's service provider business unit.

Lamb likens Fore's WDM-enhanced ATM switch to the emerging generation of terabit routers. "We're all trying to accomplish the same goal," he says. "They're using an IP backplane, and we're using a cell backplane."

Fore plans to launch the ATM switch with integrated WDM capability this week at ComNet '99 in Washington, DC, January 25-28, and plans to ship it by April. With the switch ready, Lekich says the vendors could deliver the complete architecture in two months.

Osicom and Fore also plan to demonstrate transmission of uncompressed high-definition television signals (about 1.5 Gbps) at ComNet.