| Abbreviation | Definition |
|---|---|
| DPCM | Differential Pulse Code Modulation |
| DPDCH | Dedicated Physical Data CHannel |
| DPDU | Data Protocol Data Unit |
| DPE | Dollar Phone Enterprise |
| DPL | Digital Power Line |
| DPL | Digital Private Line |
| DPO | Dial Pulse Originate |
| DPT | Dial Pulse Terminate |
| DPT | Dynamic Packet Transport |
| DQR | Directory enQuiry Restricted |
| DRI | Direct Received Invoice |
| DRS | Dial Return System |
| DRTL | Dial Repeating Tie Line |
| DRTT | Dial Repeating Tie Trunk |
| DS | Data Service |
| DS0 | Digital Signal Zero |
| DS-1 | Digital Stream 1 (1.544 mbps) |
| DS-1C | Digital Stream 1C (3.152 mbps) |
| DS-2 | Digital Stream 2 (6.312 mbps) |
| DS-4 | Digital Stream 4 (274.016 mbps) |