Quantity is how many containers you have. The result is how many tributaries fit, the path, and the leftover line rate. The choices stay in the URL, so you can share them.

Result: standard mapping

How many E2s are in a STM-256?

A STM-256 carries 3,072 E2s, per ITU-T G.707 and ITU-T G.702.

3,072

E2s in a STM-256

Working

STM-256 → 256 × STM-1 → 3 × E3 → 4 × E2

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.
4 × E2 in each E3 ITU-T G.702Four E2s.

256 STM-1s
256 × 3 = 768 E3s
256 × 3 × 4 = 3,072 E2s

Leftover capacity

13.860864 Gbit/s of each STM-256 line rate (39.813120 Gbit/s) sits outside 3,072 × 8.448 Mbit/s of E2 line rate (25.952256 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 4,712.72, which floors to 4,712 E2s by bit rate only. The standard mapping is 3,072. Use the mapping.

Share this result. Pairing page