# DSX-1 telephony interface

Specification | ANSI T1.102, T1.403
Framing | D4, ESF
Insertion and extraction | ABCD bits
Line code | AMI
Zero bits | Selectable B8ZS, jammed bit (ZCS) or no zero code suppression
Alarm signal capabilities | Yellow and red
Counts | Bipolar violation, F(t) error, and CRC error
Robbed bit | Selectable on a per-trunk basis
Loopback | Per channel and overall under software control. Automatic remote loopback with CSU option.
Interfaces | Four trunks: Two Dialogic® MD1 RJ-45 interfaces, each with two trunks