sentences:  In 2019, Controlled Interfaces demonstrated one-way optical link connectivity using optical fibers and 100G Commercial Off The Shelf transceivers.Other more sophisticated commercial offerings enable simultaneous one-way data transfer of multiple protocols that usually require bidirectional links.The German companies INFODAS and GENUA have developed software based ("logical") data diodes that use a Microkernel Operating system to ensure unidirectional data transfer.