Simultaneous high-speed data and POTS (voice) service over the same telephone line. Downstream speed ranges between 128Kbps and 8 Mbps. Upstream is usually lower than the downstream (hence, asymmetrical). The upstream rate varies from 64 Kbps to 640 Kbps. ADSL is appropriate for residential use as most home users require faster downstream speeds for file downloads, internet traffic, and video. There are 3 predominant industry standards for ADSL, all based on the DMT line code.