Rosewill 56 Kbps USB Plug and Play Modem (RNX-56USB) Hardware interface: One RJ-11 port for line connection , One USB 1.1 jack, USB compatible with USB 1.1 Hardware-based modem controller Windows Plug-n-Play V.92 protocol support and quick connect Downstream speed up to 56Kbps Upstream speed up to 48Kbps V.80 & H.324 Video Conferencing V.44 Data compression to make data transmission faster