Result: standard mapping
How many DS0s are in an ODU2?
An ODU2 carries 129,024 DS0s, per ITU-T G.709, ITU-T G.707 and ANSI T1.107. This path maps STM-64 into ODU2 as a client, then follows that client's tributaries.
129,024
DS0s in an ODU2
Working
ODU2 → 1 × STM-64 → 64 × STM-1 → 84 × DS1 → 24 × DS0
- 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.
- 24 × DS0 in each DS1 ANSI T1.10724 payload timeslots. The framing bit adds 8 kbit/s and brings the line rate to 1.544 Mbit/s.
- 1 STM-64
- 1 × 64 = 64 STM-1s
- 1 × 64 × 84 = 5,376 DS1s
- 1 × 64 × 84 × 24 = 129,024 DS0s
Leftover capacity
1.779737924 Gbit/s of each ODU2 line rate (10.037273924 Gbit/s) sits outside 129,024 × 64 kbit/s of DS0 line rate (8.257536 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 156,832.4, which floors to 156,832 DS0s by bit rate only. The standard mapping is 129,024. Use the mapping.