Short description of ModemTest 1.3.1012: ModemTest performs low level testing of dial up modems and telephone lines. Testing is preferably done with two modems but a single modem can also be used. Tests are independent of ISP and TCP/IP settings. ModemTest logs any data corruption and incorporates a modem speed test which reports the initial connection speed and the actual throughput. ModemTest helps to isolate faults with your ISP, dial up modem and telephone line.