The 8xDMT over ISDN is designed for use in a configuration with a POTS splitter, which provisions one modem directly and is physically connected to one specific subscriber line through the POTS splitter chassis. DMT/ISDN splitters are needed to separate or combine ISDN and DMT signals at the central office (CO) and at the customer site.The 8xDMT over ISDN line card supports eight ADSL modem connections, as well as DMT over ISDN protocols that employ 2B1Q- or 4B3T-based encoding. It converts ADSL modulation from the line into digital data streams to and from the NI-2 card and negotiates the line rate with the CPE when it trains and bases the rate on line quality and distance. If provisioned, the 8xDMT over ISDN rate adapts to the maximum bit rate negotiable on the line. The maximum bit rate settings are provisioned in the management software.