The JDSU Acterna SmartClass VDSL Cable Tester includes a built-in VDSL modem, which lets it synch with the local Digital Subscriber Line Access Multiplexer at suitable communication rates. On conducting the VDSL synch test with the SmartClassVDSL, one can determine display rates and measure the subscriber's connection. This tester detects VDSL errors that have occurred since the beginning, on the line that is being tested.