Zyxel OLT2412 [151/326] Two rate three color marker traffic policing

Chapter 21 Policy Rule

OLT2412 User’s Guide

151

This example creates a policy (Policy1) for the traffic flow identified via classifier Class1 (see the

classifier example in Chapter 20 on page 145). This policy forwards Class1 packets to port ge-5-4.

21.4 Two Rate Three Color Marker Traffic Policing

Traffic policing is the limiting of the input or output transmission rate of a class of traffic on the

basis of user-defined criteria. Traffic policing methods measure traffic flows against user-defined

criteria and identify it as either conforming, exceeding or violating the criteria.

Two Rate Three Color Marker (TRTCM, defined in RFC 2698) is a type of traffic policing that

identifies packets by comparing them to two user-defined rates: the Committed Information Rate

(CIR) and the Peak Information Rate (PIR). The CIR specifies the average rate at which packets are

admitted to the network. The PIR is greater than or equal to the CIR. CIR and PIR values are based

on the guaranteed and maximum bandwidth respectively as negotiated between a service provider

and client.

Two Rate Three Color Marker evaluates incoming packets and marks them with one of three colors

which refer to packet loss priority levels. High packet loss priority level is referred to as red,

medium is referred to as yellow and low is referred to as green. After TRTCM is configured and

DiffServ is enabled the following actions are performed on the colored packets:

• Red (high loss priority level) packets are dropped.

• Yellow (medium loss priority level) packets are dropped if there is congestion on the network.

• 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.

21.4.1 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.

OLT2412(config)# policy Policy1 classifier Class1 egress-port ge-5-4 outgoing-eport

OLT2412(config)# exit

OLT2412# show policy Policy1

Policy Policy1:

Classifiers:

Class1;

Parameters:

VLAN = 1; Priority = 0; DSCP = 0; TOS = 0;

Egress Port = ge-5-4;

Mirror Port = xe-3-1;

Bandwidth = 0; Out-of-profile DSCP = 0;

Action:

Send the packet to the egress port;