The psiber LM20 LanMaster 20 is a Link Tester for Verifying LAN Configuration and Operation. The psiber LM20 provides LAN installers and maintainers a tool to quickly test fast ethernet (100baseTX) and standard ethernet (10baseT) links. Auto-sensing, auto-negotiation and full duplex capabilities are optional requirements to the Fast Ethernet (IEEE 802.3u) standard. Knowing equipment capabilities is essential to optimizing network system performance, and the psiber LM20 LanMaster 20 Link Tester makes this possible. In just three seconds, the psiber LM20 LanMaster 20 Link Tester decodes the link signals and displays the exact configuration of the equipment connected to the link. The psiber LM20 LanMaster 20 Link Tester also verifies link connectivity to the far end, tests for reported faults and determines polarity of the outlet or cable.