STM-1
STM-1 is the basic SDH module at 155.520 Mbit/s, the same line rate as OC-3. Its VC-4 carries 63 VC-12s (E1), 84 VC-11s (DS1) or three VC-3s. One E4 can be mapped into the VC-4 as a client; that path is not 64 VC-12s.
- Family
- SDH
- Line rate
- 155.520 Mbit/s155,520,000 bit/s
- Payload rate
- 150.336 Mbit/s150,336,000 bit/s
- Standard
- ITU-T G.707
Same line rate as OC-3.
Contains breakdown, down to DS0 · Open in the converter
Direct mappings
| Contains | Count | Mapping | Source | Note |
|---|---|---|---|---|
| 1 E4 | 1 | Client mapping | ITU-T G.707 | Asynchronous E4 mapped into the C-4 / VC-4. This client holds 64 E1s internally; the VC-12 tributary count of an STM-1 is 63. |
| 3 E3s | 3 | Tributary | ITU-T G.707 | Three VC-3s, each carrying an E3. |
| 3 DS3s | 3 | Tributary | ITU-T G.707 | Three VC-3s, each able to carry a DS3. |
| 63 E1s | 63 | Tributary | ITU-T G.707 | 63 VC-12 tributaries: 3 TUG-3 × 7 TUG-2 × 3 TU-12. |
| 84 DS1s | 84 | Tributary | ITU-T G.707 | 84 VC-11 tributaries: 3 TUG-3 × 7 TUG-2 × 4 TU-11. |