Result: standard mapping
How many DS1s are in an OTU2?
An OTU2 carries 5,376 DS1s, per ITU-T G.709 and ITU-T G.707. This path maps STM-64 into ODU2 as a client, then follows that client's tributaries.
5,376
DS1s in an OTU2
Working
OTU2 → 1 × ODU2 → 1 × STM-64 → 64 × STM-1 → 84 × DS1
- 1 × ODU2 in each OTU2 ITU-T G.709The OTU2 frame carries exactly one ODU2.
- 1 × STM-64 in each ODU2 ITU-T G.709Client mappingCBR STM-64 mapped into OPU2.
- 64 × STM-1 in each STM-64 ITU-T G.70764 × STM-1.
- 84 × DS1 in each STM-1 ITU-T G.70784 VC-11 tributaries: 3 TUG-3 × 7 TUG-2 × 4 TU-11.
- 1 ODU2
- 1 × 1 = 1 STM-64
- 1 × 1 × 64 = 64 STM-1s
- 1 × 1 × 64 × 84 = 5,376 DS1s
Leftover capacity
2.408681316 Gbit/s of each OTU2 line rate (10.709225316 Gbit/s) sits outside 5,376 × 1.544 Mbit/s of DS1 line rate (8.300544 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 6,936.02, which floors to 6,936 DS1s by bit rate only. The standard mapping is 5,376. Use the mapping.