Result: standard mapping
How many DS0s are in an OC-768?
An OC-768 carries 516,096 DS0s, per Telcordia GR-253 and ANSI T1.107.
516,096
DS0s in an OC-768
Working
OC-768 → 768 × OC-1 (STS-1) → 28 × DS1 → 24 × DS0
- 768 × OC-1 (STS-1) in each OC-768 Telcordia GR-253768 × OC-1 (STS-1). Channelized OC-768 is 768 STS-1s.
- 28 × DS1 in each OC-1 (STS-1) Telcordia GR-253Seven VT groups × four VT1.5 (DS1).
- 24 × DS0 in each DS1 ANSI T1.10724 payload timeslots. The framing bit adds 8 kbit/s and brings the line rate to 1.544 Mbit/s.
- 768 OC-1s
- 768 × 28 = 21,504 DS1s
- 768 × 28 × 24 = 516,096 DS0s
Leftover capacity
6.782976 Gbit/s of each OC-768 line rate (39.813120 Gbit/s) sits outside 516,096 × 64 kbit/s of DS0 line rate (33.030144 Gbit/s). That remainder is overhead, fixed stuff or justification. It is not another whole tributary.
By bit rate only
Dividing the line rates gives 622,080, which floors to 622,080 DS0s by bit rate only. The standard mapping is 516,096. Use the mapping.