Result: standard mapping
How many DS1s are in a STM-64?
A STM-64 carries 5,376 DS1s, per ITU-T G.707.
5,376
DS1s in a STM-64
Working
STM-64 → 64 × STM-1 → 84 × DS1
- 64 × STM-1 in each STM-64 ITU-T G.70764 × STM-1.
- 84 × DS1 in each STM-1 ITU-T G.70784 VC-11 tributaries: 3 TUG-3 × 7 TUG-2 × 4 TU-11.
- 64 STM-1s
- 64 × 84 = 5,376 DS1s
Leftover capacity
1.652736 Gbit/s of each STM-64 line rate (9.953280 Gbit/s) sits outside 5,376 × 1.544 Mbit/s of DS1 line rate (8.300544 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 6,446.42, which floors to 6,446 DS1s by bit rate only. The standard mapping is 5,376. Use the mapping.