The ATLAS 550 NxT1 HSSI Module combines multiple T1 circuits into a single logical data stream to an integral High-Speed Serial Interface (HSSI) port. This hot-swappable user module uses an ADTRAN proprietary protocol to support point-to-point, high-speed data applications. The inverse multiplexing capacity of the module accommodates eight T1s, and the module automatically adjusts the data rate to the HSSI port upon loss of one or more T1 circuits. In addition to the HSSI port, four T1 ports are included on the module itself, while additional T1 ports can be provided using other ATLAS 550 T1 modules.