Result: standard mapping
How many E3s are in an ODU3?
An ODU3 carries 768 E3s, per ITU-T G.709 and ITU-T G.707. This path maps STM-256 into ODU3 as a client, then follows that client's tributaries.
768
E3s in an ODU3
Working
ODU3 → 1 × STM-256 → 256 × STM-1 → 3 × E3
- 1 × STM-256 in each ODU3 ITU-T G.709Client mappingCBR STM-256 mapped into OPU3.
- 256 × STM-1 in each STM-256 ITU-T G.707256 × STM-1.
- 3 × E3 in each STM-1 ITU-T G.707Three VC-3s, each carrying an E3.
- 1 STM-256
- 1 × 256 = 256 STM-1s
- 1 × 256 × 3 = 768 E3s
Leftover capacity
13.924594983 Gbit/s of each ODU3 line rate (40.319218983 Gbit/s) sits outside 768 × 34.368 Mbit/s of E3 line rate (26.394624 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 1,173.16, which floors to 1,173 E3s by bit rate only. The standard mapping is 768. Use the mapping.