DMS 250/300
These are typical line ups of Nortel DMS digital trunk frames. Each line up can have multiple trunk frames, and each trunk frame has two DTC's. A DTC has either 20 T1's or 16 E1's, so each frame has 960 trunks in either T1 or E1 configuration and can support SS-7, C-7, ISDN, MF, DTMF, or R2 signaling.