Result: standard mapping
How many E0s are in an OTU3?
An OTU3 carries 483,840 E0s, per ITU-T G.709, ITU-T G.707 and ITU-T G.704. This path maps STM-256 into ODU3 as a client, then follows that client's tributaries.
483,840
E0s in an OTU3
Working
OTU3 → 1 × ODU3 → 1 × STM-256 → 256 × STM-1 → 63 × E1 → 30 × E0
- 1 × ODU3 in each OTU3 ITU-T G.709The OTU3 frame carries exactly one ODU3.
- 1 × STM-256 in each ODU3 ITU-T G.709Client mappingCBR STM-256 mapped into OPU3.
- 256 × STM-1 in each STM-256 ITU-T G.707256 × STM-1.
- 63 × E1 in each STM-1 ITU-T G.70763 VC-12 tributaries: 3 TUG-3 × 7 TUG-2 × 3 TU-12.
- 30 × E0 in each E1 ITU-T G.70430 voice channels in 32 timeslots. TS0 is framing and TS16 is channel-associated signalling.
- 1 ODU3
- 1 × 1 = 1 STM-256
- 1 × 1 × 256 = 256 STM-1s
- 1 × 1 × 256 × 63 = 16,128 E1s
- 1 × 1 × 256 × 63 × 30 = 483,840 E0s
Leftover capacity
12.052653559 Gbit/s of each OTU3 line rate (43.018413559 Gbit/s) sits outside 483,840 × 64 kbit/s of E0 line rate (30.965760 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 672,162.71, which floors to 672,162 E0s by bit rate only. The standard mapping is 483,840. Use the mapping.