What an ODU4 contains

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.

ODU4 → 10 × ODU2 → 1 × STM-64 → 64 × STM-1 → 84 × DS1 → 24 × DS0

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

E1 mapping: 40,320 E1s, which is 1,209,600 voice channels at 30 per E1. E1s in an ODU4.

Down to DS0

ODU4

10 × ODU2 ITU-T G.709Ten ODU2s use all 80 tributary slots, eight slots each.
1. 1 × STM-64 ITU-T G.709Client mappingCBR STM-64 mapped into OPU2.
  1. 64 × STM-1 ITU-T G.70764 × STM-1.
    1. 84 × DS1 ITU-T G.70784 VC-11 tributaries: 3 TUG-3 × 7 TUG-2 × 4 TU-11.
      1. 24 × DS0 ANSI T1.10724 payload timeslots. The framing bit adds 8 kbit/s and brings the line rate to 1.544 Mbit/s.
    2. 1 × E4 ITU-T G.707Client mappingAsynchronous E4 mapped into the C-4 / VC-4. This client holds 64 E1s internally; the VC-12 tributary count of an STM-1 is 63.
    3. 3 × E3 ITU-T G.707Three VC-3s, each carrying an E3.
    4. 3 × DS3 ITU-T G.707Three VC-3s, each able to carry a DS3.
    5. 63 × E1 ITU-T G.70763 VC-12 tributaries: 3 TUG-3 × 7 TUG-2 × 3 TU-12.
  2. 4 × STM-16 ITU-T G.7074 × STM-16.
  3. 16 × STM-4 ITU-T G.70716 × STM-4.
2. 4 × ODU1 ITU-T G.709Four ODU1s. Each ODU1 takes two of the eight 1.25 Gbit/s tributary slots.
3. 8 × ODU0 ITU-T G.709Eight ODU0s, one per 1.25 Gbit/s tributary slot.
4. 1 × OC-192 ITU-T G.709Client mappingCBR OC-192, the same client rate as STM-64, mapped into OPU2.
40 × ODU1 ITU-T G.70940 ODU1s, two slots each.
80 × ODU0 ITU-T G.70980 ODU0s, one per 1.25 Gbit/s tributary slot.
2 × ODU3 ITU-T G.709Each ODU3 takes 31 of the 80 ODU4 tributary slots, so 2 fit and 18 slots stay unused.

ODU4 rates and aliases