EXFO FTB-8510B Guia Del Usuario página 1253

The OTU, ODU (including the ODU tandem connection) and OPU layers
can all be analyzed and monitored. As per ITU G.709, current test solutions
offer these possibilities using three line rates:
OTU1 (255/238 x 2.488 320 Gbps ˜ 2.666057143 Gbps) also referred to
as 2.7 Gbps
OTU2 (255/237 x 9.953280 Gbps ˜ 10.709225316 Gbps) also referred to
as 10.7 Gbps
OTU3 (255/236 x 39.813120 Gbps ˜ 43.018413559 Gbps) also referred to
as 43 Gbps
Each line rate is adapted to service different client signals:
OC-48/STM-16 is transported via OTU1
OC-192/STM-64 is transported via OTU2
OC-768/STM-256 is transported via OTU3
Null Client (All 0s) is transported via OTUk (k = 1, 2, 3)
PRBS 231-1 is transported via OTUk (k = 1, 2, 3)
In order to map client signals via ITU G.709, they are encapsulated using
the structure illustrated in the following figure.
SONET/SDH Application
Basic OTN Transport Structure
G.709 Optical Transport Network (OTN)
Glossary
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