Result: standard mapping
How many DS0s are in an ODU4?
An ODU4 carries 1,290,240 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.
1,290,240
DS0s in an ODU4
Working
ODU4 → 10 × ODU2 → 1 × STM-64 → 64 × STM-1 → 84 × DS1 → 24 × DS0
- 10 × ODU2 in each ODU4 ITU-T G.709Ten ODU2s use all 80 tributary slots, eight slots each.
- 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.
- 10 ODU2s
- 10 × 1 = 10 STM-64s
- 10 × 1 × 64 = 640 STM-1s
- 10 × 1 × 64 × 84 = 53,760 DS1s
- 10 × 1 × 64 × 84 × 24 = 1,290,240 DS0s
Leftover capacity
22.219085815 Gbit/s of each ODU4 line rate (104.794445815 Gbit/s) sits outside 1,290,240 × 64 kbit/s of DS0 line rate (82.575360 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 1,637,413.21, which floors to 1,637,413 DS0s by bit rate only. The standard mapping is 1,290,240. Use the mapping.