A fault-testing node for a connectionless data link has at least two opposing communication ports; a soft switch for controlling port-to-port data flow through the device; and an instance of software for modifying packet header information. The node enables loop-back testing by one or more port-to-port...http://www.google.de/patents/US7085238?utm_source=gb-gplus-sharePatent US7085238 - Smartjack for fault-testing network segments on Ethernet and other internet protocol network architectures
