EXFO FTB-800 Series for FTB-1 - Manual (Page 570)

Glossary
560 FTB-700G/800 Series
G.709 Optical Transport Network (OTN)
ODUflex
ODUflex provides the capability to carry client payload of variable size with
a container size of 1.244 Gbit/s granularity. An ODUflex (L) signal can be
transported once multiplexed in an ODUk (H) signal, the multiplexer in this
case handles tributary slots of 1.244 Gbit/s and has a Payload Type 21. The
ODUflex function can be used to transport 2 signal categories mapped in
ODTUk.ts using GMP:

Ethernet in ODUflex over GFP-F signal
The Ethernet packets are mapped in GFP-F as specified in G.7041, the
packets are processed as follows:

The Start of Frame Delineation bytes are terminated

Inter Frame Gaps bytes are terminated

PCS coding is terminated

GFP overhead bytes added
Since the PCS coding is terminated, it is not possible to transport the
Ethernet Link status transparently but it is accommodated by the
Forward Defect Indication (FDI) and Remote Defect Indication (RDI)
alarms over GFP. The RDI is used to carry the Remote Fault alarm while
the FDI is used to carry the Local Fault.
GFP-F provides rate adaptation between the incoming Ethernet signal
and the outgoing OPUflex transport signal. This brings the fact that
GMP is operated at a fixed Cm value close to the maximum server
capacity.

CBR over ODUflex signal
ODUflex can transport Constant Bit Rate signal (bulk filled Test pattern)
as Client of the ODUflex CBR function. This CBR function needs a
Pattern generator that can operate at a data rate specified by the user,
the range of the available data rates is qualified by the Bandwidth
management function.