About the data
MuxRates answers a question generic unit converters get wrong: how many lower-rate channels fit in a higher-rate signal. North American PDH, European PDH, SONET, SDH and OTN were defined by different bodies, and they do not divide into each other.
A DS3 carries 28 DS1s. An STS-1 carries one DS3 or 28 VT1.5s. An STM-1 carries 63 E1s. An OC-3 carries 84 DS1s. Those are mapping rules from the standards.
When a container has more than one standard mapping, MuxRates prefers the native tributary multiplex over a mapped client signal. An STM-1 therefore shows 63 E1s (VC-12) rather than the 64 E1s inside an E4 mapped into the same VC-4.
OTN line rates are the ITU-T G.709 nominal formulas rounded to the nearest bit/s. PDH, SONET and SDH line rates are exact. Payload rates are the DS0 aggregate for PDH voice channels, the SONET synchronous payload envelope or the matching SDH VC aggregate, and the OTN OPU payload. An OTUk payload rate is the ODUk it wraps.
Ethernet, FlexE, DWDM channel plans and byte-level overhead diagrams are outside this reference. If a count is wrong, send a correction and name the clause.
Standards used
ANSI T1.107, ITU-T G.702/G.704/G.707/G.709, Telcordia GR-253.
- ANSI T1.107: North American DS0–DS3 hierarchy
- ITU-T G.702: E-carrier bit rates and multiplex counts
- ITU-T G.704: E1 frame: 30 voice channels in 32 timeslots
- ITU-T G.707: SDH STM-N and VC tributaries
- ITU-T G.709: OTN ODUk, OTUk, tributary slots and nominal rates
- Telcordia GR-253: SONET OC-N, STS-1 and virtual tributaries