Three types of DTUs are available — the Alcatel
2751, Alcatel 2752 and Alcatel 2753 MainStreet
DTUs with TIA/EIA-232 (RS-232), X.21 and V.35
user ports, respectively. All three DTUs share a
common network port and can be mixed and
matched on the same 6- and 12-port line cards.
Subrate (<64 kb/s) data is supported and can be
multiplexed onto the same DS0. This multiplexing
of data allows for efficient utilization of bandwidth
and real cost savings.