Result: standard mapping
How many DS2s are in a STM-0?
A STM-0 carries 7 DS2s, per ITU-T G.707 and ANSI T1.107. This path maps DS3 into STM-0 as a client, then follows that client's tributaries.
7
DS2s in a STM-0
Working
STM-0 → 1 × DS3 → 7 × DS2
- 1 × DS3 in each STM-0 ITU-T G.707Client mappingOne VC-3 carrying a DS3.
- 7 × DS2 in each DS3 ANSI T1.107M13 multiplex: seven DS2s.
- 1 DS3
- 1 × 7 = 7 DS2s
Leftover capacity
7.656 Mbit/s of each STM-0 line rate (51.840 Mbit/s) sits outside 7 × 6.312 Mbit/s of DS2 line rate (44.184 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 8.21, which floors to 8 DS2s by bit rate only. The standard mapping is 7. Use the mapping.