Quantity is how many containers you have. The result is how many tributaries fit, the path, and the leftover line rate. The choices stay in the URL, so you can share them.
Result: standard mapping
How many OC-12s are in an OTU4?
An OTU4 carries 160 OC-12s, per ITU-T G.709 and Telcordia GR-253. This path maps OC-192 into ODU2 as a client, then follows that client's tributaries.
160
OC-12s in an OTU4
Working
OTU4 → 1 × ODU4 → 10 × ODU2 → 1 × OC-192 → 16 × OC-12
- 1 × ODU4 in each OTU4 ITU-T G.709The OTU4 frame carries exactly one ODU4.
- 10 × ODU2 in each ODU4 ITU-T G.709Ten ODU2s use all 80 tributary slots, eight slots each.
- 1 × OC-192 in each ODU2 ITU-T G.709Client mappingCBR OC-192, the same client rate as STM-64, mapped into OPU2.
- 16 × OC-12 in each OC-192 Telcordia GR-25316 × OC-12. Channelized OC-192 is 192 STS-1s.
- 1 ODU4
- 1 × 10 = 10 ODU2s
- 1 × 10 × 1 = 10 OC-192s
- 1 × 10 × 1 × 16 = 160 OC-12s
Leftover capacity
12.277173568 Gbit/s of each OTU4 line rate (111.809973568 Gbit/s) sits outside 160 × 622.080 Mbit/s of OC-12 line rate (99.532800 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 179.73, which floors to 179 OC-12s by bit rate only. The standard mapping is 160. Use the mapping.
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