The Total Access 4303 (TA 4303) is a modular, full-featured platform designed to support several functions associated with GR-303 concentration. TA 4303 is capable of terminating up to 128 T1s (DSX-1 format) with the flexibility to assign any T1 as input from the switch or as a concentrated output to the user. TA 4303 also provides connectivity for up to four DS3 interfaces, providing additional flexibility for connection to the switch or to the network. The unit uses full Digital Cross Connect functionality, allowing the separation of non-concentrated data circuits from concentrated voice circuits for mixed-mode applications.