EXFO FTB-8500 Series for FTB-200 - Manual (Page 141)

I/F Setup Tabs
Ethernet and Fibre Channel Application 127
Port Setup

Flow Control
Available with Frame Analyzer (FTB-8510B and FTB-8510G), RFC
2544, and TCP Throughput stest only. Flow control is not supported
for EtherSAM, BERT and Smart Loopback tests. When Flow Control is
enabled, the Ethernet and Fibre Channel Application will stop
transmitting for the requested time value specified by the valid flow
control frame received.
None (FTB-8510B/FTB-8120NGE/FTB-8130NGE/FTB-8525/FTB-8535):
pause frame received are ignored and no pause frame are transmitted.
Note: Flow Control should be set to None with Half Duplex mode.

Local Clock Only available for 1Gbps electrical when auto-negotiation
is disabled. Choices are Local, Remote, and Automatic. The default
setting is Automatic.