... 2/K56Flex 5,600bps Transmission Protocol Product description56K USB Modem, offers universal Plug-and-play USB interface and ... supports data compress protocol, V.90 (56Kbps), V.34 (33.6Kbps) protocol standardsFeaturesComply with external USB 56K Modem, supports hot plug and ... .92 , V.90 , V.34 , V.32bis , V.32 , V.22bis , V.22 , V.23 , V.21 , Bell212A , and 103 Fax protocol: V.17, V.29, V.27ter and V. ...