EXFO FTB-800 Series for FTB-1 - Manual (Page 57)

Test Setup - Test Applications
NetBlazer 47
SONET/SDH - DSn/PDH BERT
SONET/SDH - DSn/PDH BERT
Allows validation of the DSn or PDH embedded in SONET or SDH transport
protocol by performing a BERT test to check the traffic or payload stability
over a network facility.

Typical SONET/SDH - DSn/PDH BERT test applications:
Network
under test
Testing Unit DUT Loopback
FTB-700G/800 Series
Network
under test
Testing Unit Testing Unit
FTB-700G/800 Series FTB-700G/800 Series