EXFO FTB-8500 Series for FTB-500 - Manual (Page 514)

Pop-Up Windows
500 FTB-8500 Series and FTB-8120NGE/8130NGE
Advanced TOS/DS
Advanced TOS/DS
Enable Differentiated Services
Allows enabling the Differentiated Services (DS). This setting is disabled by
default.
DS
Note: DS is available when Enable Differentiated Services is enabled.

DSCP Codepoints: Select the DSCP Codepoints. Choices are:
000000 (CS0), 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), and
User Defined. The default setting is 000000 (CS0).

User Defined Codes: Enter a user defined code. Choices are from
hexadecimal 00 to 3F. The default setting is 00. User Defined Codes is
available when User Defined has been selected from the DSCP
codepoints.

ECN: Select the ECN field. Choices are 00 (Not-ECT), 01 (ECT-1),
10 (ECT 0), and 11 (CE). The default setting is 00 (Not-ECT).