Result: standard mapping
How many E2s are in an ODU2?
An ODU2 carries 768 E2s, per ITU-T G.709, ITU-T G.707 and ITU-T G.702. This path maps STM-64 into ODU2 as a client, then follows that client's tributaries.
768
E2s in an ODU2
Working
ODU2 → 1 × STM-64 → 64 × STM-1 → 3 × E3 → 4 × E2
- 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.
- 3 × E3 in each STM-1 ITU-T G.707Three VC-3s, each carrying an E3.
- 4 × E2 in each E3 ITU-T G.702Four E2s.
- 1 STM-64
- 1 × 64 = 64 STM-1s
- 1 × 64 × 3 = 192 E3s
- 1 × 64 × 3 × 4 = 768 E2s
Leftover capacity
3.549209924 Gbit/s of each ODU2 line rate (10.037273924 Gbit/s) sits outside 768 × 8.448 Mbit/s of E2 line rate (6.488064 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 1,188.12, which floors to 1,188 E2s by bit rate only. The standard mapping is 768. Use the mapping.