Result: standard mapping
How many DS2s are in an ODU2?
An ODU2 carries 1,344 DS2s, per ITU-T G.709 and Telcordia GR-253. This path maps OC-192 into ODU2 as a client, then follows that client's tributaries.
1,344
DS2s in an ODU2
Working
ODU2 → 1 × OC-192 → 192 × OC-1 (STS-1) → 7 × DS2
- 1 × OC-192 in each ODU2 ITU-T G.709Client mappingCBR OC-192, the same client rate as STM-64, mapped into OPU2.
- 192 × OC-1 (STS-1) in each OC-192 Telcordia GR-253192 × OC-1 (STS-1). Channelized OC-192 is 192 STS-1s.
- 7 × DS2 in each OC-1 (STS-1) Telcordia GR-253Seven VT groups, one VT6 (DS2) each.
- 1 OC-192
- 1 × 192 = 192 OC-1s
- 1 × 192 × 7 = 1,344 DS2s
Leftover capacity
1.553945924 Gbit/s of each ODU2 line rate (10.037273924 Gbit/s) sits outside 1,344 × 6.312 Mbit/s of DS2 line rate (8.483328 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 1,590.18, which floors to 1,590 DS2s by bit rate only. The standard mapping is 1,344. Use the mapping.