It uses a rapidspanning tree protocol for fast redundant rings. This ensures messages transmit even after breaks in a communications pathway. The switch also detects and reports network problems before they seriously affect network operations. The unit has a self-test and alarmoutput signal and authentication and encryption features. And it includes Linux tools.

Sixnet, 331 Ushers Rd., Box 767, Clifton Park, NY 12065, (518) 877-5173,