Result: standard mapping
How many E2s are in a STM-0?
A STM-0 carries 4 E2s, per ITU-T G.707 and ITU-T G.702. This path maps E3 into STM-0 as a client, then follows that client's tributaries.
4
E2s in a STM-0
Working
STM-0 → 1 × E3 → 4 × E2
- 1 × E3 in each STM-0 ITU-T G.707Client mappingOne TU-3 / VC-3 carrying an E3.
- 4 × E2 in each E3 ITU-T G.702Four E2s.
- 1 E3
- 1 × 4 = 4 E2s
Leftover capacity
18.048 Mbit/s of each STM-0 line rate (51.840 Mbit/s) sits outside 4 × 8.448 Mbit/s of E2 line rate (33.792 Mbit/s). That remainder is overhead, fixed stuff or justification. It is not another whole tributary.
By bit rate only
Dividing the line rates gives 6.13, which floors to 6 E2s by bit rate only. The standard mapping is 4. Use the mapping.