Netgear M4100-26-POE (FSM7226Pv1h1) - 24‐port FE + 2 GE Combo L2 Managed PoE Switch 管理者ガイド

This chapter describes Class of Service (CoS) queue mapping, CoS Configuration, and 
traffic shaping features. Each port has one or more queues for packet transmission. During 
configuration, you can determine the mapping and configuration of these queues. 

Based on the service rate and other criteria you configure, queues provide preference to 
specified packets. If a delay is necessary, the system holds packets until the scheduler 
authorizes transmission. As queues become full, packets are dropped. Packet drop 
precedence indicates the packet’s sensitivity to being dropped during queue congestion. 

Select per interface configuration scheme:

You can configure CoS mapping, queue parameters, and queue management are 
configurable per interface.

Queue management is configurable per interface.

Some hardware implementations allow queue depth management using tail dropping or 
weighted random early discard (WRED).

Some hardware implementations allow queue depth management using tail dropping.

The operation of CoS queuing involves queue mapping and queue configuration.

CoS queue mapping uses trusted and untrusted ports.

The system takes at face value certain priority designations for arriving packets.

Trust applies only to packets that have that trust information.

There can be only one trust field at a time - per port.

802.1p user priority (This is the default trust mode and is managed through switching 
configuration.)

IP precedence

IP DiffServ Code Point (DSCP)

The system can assign the service level based upon the 802.1p priority field of the L2 
header. You configure this by mapping the 802.1p priorities to one of three traffic class 
queues. These queues are:

Queue 2. Minimum of 50 percent of available bandwidth

Queue 1. Minimum of 33 percent of available bandwidth

Queue 0. Lowest priority, minimum of 17 percent of available bandwidth

For untagged traffic, you can specify the default 802.1p priority on a per-port basis.