Trtcm - Color-Blind Mode; Trtcm - Color-Aware Mode; Figure 118 Trtcm - Color-Blind Mode; Figure 119 Trtcm - Color-Aware Mode - ZyXEL Communications GS-3012F/3012 User Manual

• Green (low loss priority level) packets are forwarded.
trTCM operates in one of two modes: color-blind or color-aware. In color-blind mode, packets
are marked based on evaluating against the PIR and CIR regardless of if they have previously
been marked or not. In the color-aware mode, packets are marked based on both existing color
and evaluation against the PIR and CIR. If the packets do not match any of colors, then the
packets proceed unchanged.

25.2.1 trTCM - Color-blind Mode

All packets are evaluated against the PIR. If a packet exceeds the PIR it is marked red.
Otherwise it is evaluated against the CIR. If it exceeds the CIR then it is marked yellow.
Finally, if it is below the CIR then it is marked green.

Figure 118 trTCM - Color-blind Mode

25.2.2 trTCM - Color-aware Mode

In color-aware mode the evaluation of the packets uses the existing packet loss priority. trTCM
can increase a packet loss priority of a packet but it cannot decrease it. Packets that have been
previously marked red or yellow can only be marked with an equal or higher packet loss
priority.
Packets marked red (high packet loss priority) continue to be red without evaluation against
the PIR or CIR. Packets marked yellow can only be marked red or remain yellow so they are
only evaluated against the PIR. Only the packets marked green are first evaluated against the
PIR and then if they don't exceed the PIR level are they evaluated against the CIR.

Figure 119 trTCM - Color-aware Mode

GS-3012/GS-3012F User's Guide
Exceed NO
PIR?
YES
High Packet
Loss
NO
Exceed
Red?
PIR?
YES
YES
High Packet High Packet
Loss Loss
Chapter 25 Two Rate Three Color Marker
Exceed
NO
CIR?
YES
Medium Packet
Loss
NO NO
Yellow?
YES
Medium Packet
Loss
Low Packet
Loss
NO
Exceed
Low Packet
CIR? Loss
YES
Medium Packet
Loss
209