Result: standard mapping
How many OC-12s are in an ODU3?
An ODU3 carries 64 OC-12s, per ITU-T G.709 and Telcordia GR-253. This path maps OC-768 into ODU3 as a client, then follows that client's tributaries.
64
OC-12s in an ODU3
Working
ODU3 → 1 × OC-768 → 64 × OC-12
- 1 × OC-768 in each ODU3 ITU-T G.709Client mappingCBR OC-768, the same client rate as STM-256, mapped into OPU3.
- 64 × OC-12 in each OC-768 Telcordia GR-25364 × OC-12. Channelized OC-768 is 768 STS-1s.
- 1 OC-768
- 1 × 64 = 64 OC-12s
Leftover capacity
506.098983 Mbit/s of each ODU3 line rate (40.319218983 Gbit/s) sits outside 64 × 622.080 Mbit/s of OC-12 line rate (39.813120 Gbit/s). That remainder is overhead, fixed stuff or justification. It is not another whole tributary.