Result: standard mapping
How many ODU1s are in an OTU4?
An OTU4 carries 40 ODU1s, per ITU-T G.709.
40
ODU1s in an OTU4
Working
OTU4 → 1 × ODU4 → 40 × ODU1
- 1 × ODU4 in each OTU4 ITU-T G.709The OTU4 frame carries exactly one ODU4.
- 40 × ODU1 in each ODU4 ITU-T G.70940 ODU1s, two slots each.
- 1 ODU4
- 1 × 40 = 40 ODU1s
Leftover capacity
11.858968528 Gbit/s of each OTU4 line rate (111.809973568 Gbit/s) sits outside 40 × 2.498775126 Gbit/s of ODU1 line rate (99.95100504 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 44.74, which floors to 44 ODU1s by bit rate only. The standard mapping is 40. Use the mapping.