Result: standard mapping
How many DS0s are in an E3?
An E3 carries 480 DS0s, per ITU-T G.702 and ITU-T G.704.
480
DS0s in an E3
Working
E3 → 16 × E1 → 30 × E0 → 1 × DS0
- 16 × E1 in each E3 ITU-T G.70216 E1s, which is 4 E2s × 4 E1s.
- 30 × E0 in each E1 ITU-T G.70430 voice channels in 32 timeslots. TS0 is framing and TS16 is channel-associated signalling.
- 1 × DS0 in each E0 ITU-T G.702E0 and DS0 are each one 64 kbit/s PCM channel.
- 16 E1s
- 16 × 30 = 480 E0s
- 16 × 30 × 1 = 480 DS0s
Leftover capacity
3.648 Mbit/s of each E3 line rate (34.368 Mbit/s) sits outside 480 × 64 kbit/s of DS0 line rate (30.720 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 537, which floors to 537 DS0s by bit rate only. The standard mapping is 480. Use the mapping.