The V.110 12-port module includes onboard terminal adapters (TAs) that can terminate up to 12 V.110 bit rate adapted digital calls. Bit rate adaption protocols map the PC communications port speed (for example, 9600, 19200, and 38400 bps) to the faster data rate (64000 bps) of Integrated Services Digital Network (ISDN) B channels. The V.110 module supports a maximum data rate of 19200 bps on all ports simultaneously.The V.110 rate adaption protocol is used primarily for: adapting the slower asynchronous data rates (from 600 to 38400 bps) of older equipment to the faster data rate (64000 bps) of ISDN B channels; cellular data applications over the Global System for Mobile Telecommunications (GSM) network; asynchronous connectivity for European ISDN TAs.