Result: standard mapping
How many E0s are in an E4?
An E4 carries 1,920 E0s, per ITU-T G.702 and ITU-T G.704.
1,920
E0s in an E4
Working
E4 → 64 × E1 → 30 × E0
- 64 × E1 in each E4 ITU-T G.70264 E1s, which is 4 E3s × 16 E1s.
- 30 × E0 in each E1 ITU-T G.70430 voice channels in 32 timeslots. TS0 is framing and TS16 is channel-associated signalling.
- 64 E1s
- 64 × 30 = 1,920 E0s
Leftover capacity
16.384 Mbit/s of each E4 line rate (139.264 Mbit/s) sits outside 1,920 × 64 kbit/s of E0 line rate (122.880 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 2,176, which floors to 2,176 E0s by bit rate only. The standard mapping is 1,920. Use the mapping.