Waterfall Unidirectional Security Gateways enable safe visibility into OT networks. Unidirectional Gateway hardware is physically able to transmit information in only one direction. Software connectors unidirectionally replicate servers and emulate devices. Users and applications on the destination network interact normally and bi-directionally with Waterfall’s faithful replica systems, keeping industrial networks safe from cyber attacks. Waterfall’s connectors can run on Waterfall-supplied Host Modules, customer-supplied equipment and even virtual machines. Waterfall’s commercial-off-the-shelf (COTS) connectors are supported on a wide variety of Windows and Linux platforms, and select connectors are supported on AIX, Solaris and VxWorks.