ZyXEL MES3500-24F User Guide - Page 270

Chapter 35 Differentiated Services 35.2.1 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 153 TRTCM-Color-blind Mode Exceed NO PIR? YES Exceed NO CIR? YES Low Packet Loss High Packet Loss Medium Packet Loss 35.2.2 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 154 TRTCM-Color-aware Mode NO Red? YES Exceed NO PIR? YES NO Yellow? YES Exceed NO Low Packet CIR? Loss YES High Packet Loss High Packet Loss Medium Packet Medium Packet Loss Loss 35.3 Activating DiffServ Activate DiffServ to apply marking rules or IEEE 802.1p priority mapping on the selected port(s). 270 MES3500-24/24F User's Guide