LanMaster 30 - Universal Link Checker, indicating which service is at the terminal box is available , the device LanMaster 30 identified in a few seconds whether a socket is active and rest which signals. The LanMaster performs a link test and checked for Fast Ethernet (100baseTX) , standard Ethernet (10baseT) and identified the following services:. analog phone, ISDN, PBX, or Token Ring network problems or duplex mode due to faulty auto-sensing and negotiation can be so easy to find. Finally, can by flashing the Link LED on the assign each of the hub or switch port of the socket. It protects against incompatible impressed currents or voltages that can destroy your network cards.