The perfDSCP testvar is used to specify a DSCP value for the IPv4 or IPv6 connection. For IPv4 sessions, the 6-bit DSCP field is encoded in the IPv4 DS/TOS byte. For IPv6, the 6-bit DSCP field is encoded in the IPv6 Traffic Class.
NOTE: The DSCP value is only the upper 6-bits of the 8-bit field, however you must specify the value for the full 8-bits. The lower 2-bits are reseved for the ECN value, which should always have the value 0.
0 1 2 3 4 5 6 7 +—–+—–+—–+—–+—–+—–+—–+—–+ | DS FIELD, DSCP | ECN FIELD | +—–+—–+—–+—–+—–+—–+—–+—–+
DSCP: Differentiated Services CodePoint ECN: Explicit Congestion Notification
This means if you want to specify the decimal value 46 for DSCP, this value must be shifted two bits, resulting in the decimal value 184, which is the equivalent value when using all 8-bits.
This testvar may also be specified in hex notation i.e 0xb8 is equal to 184 in decimal format for the entire 8-bit value of the combined DSCP and ECN.
This testvar was added in CDRouter 11.3