Result: standard mapping
How many DS3s are in an OC-3?
An OC-3 carries 3 DS3s, per Telcordia GR-253.
3
DS3s in an OC-3
Working
OC-3 → 3 × OC-1 (STS-1) → 1 × DS3
- 3 × OC-1 (STS-1) in each OC-3 Telcordia GR-2533 × OC-1 (STS-1). Channelized OC-3 is 3 STS-1s.
- 1 × DS3 in each OC-1 (STS-1) Telcordia GR-253Asynchronous DS3 mapping into the STS-1 synchronous payload envelope.
- 3 OC-1s
- 3 × 1 = 3 DS3s
Leftover capacity
21.312 Mbit/s of each OC-3 line rate (155.520 Mbit/s) sits outside 3 × 44.736 Mbit/s of DS3 line rate (134.208 Mbit/s). That remainder is overhead, fixed stuff or justification. It is not another whole tributary.