EXFO FTB-800 Series for FTB-1 - Manual (Page 172)

Test Setup - Test Configurator, Timer, and System
162 FTB-700G/800 Series
MAC/IP/UDP
Differentiated Services (available when DS is selected).

DSCP Codepoints:
000000 (CS0) (default), 001000 (CS1), 010000 (CS2),
011000 (CS3), 100000 (CS4), 101000 (CS5), 110000 (CS6),
111000 (CS7), 001010 (AF11), 001100 (AF12), 001110 (AF13),
010010 (AF21), 010100 (AF22), 010110 (AF23), 011010 (AF31),
011100 (AF32), 011110 (AF33), 100010 (AF41), 100100 (AF42),
100110 (AF43), 101110 (EF), 110011 (51), 110110 (54), or
User Defined.

User Defined Codes, available when User Defined has been
selected from the DSCP codepoints, allows to enter a user defined
code from hexadecimal 00 (default) to 3F once the TOS/DS
Config pop-up is closed.

ECN allows the selection of the Explicit Congestion Notification
code: 00 (Not-ECT) (default), 01 (ECT-1), 10 (ECT 0), or 11 (CE).