User's Guide

Table Of Contents

TRENDnet User’s Guide

Web Smart Switch Series

QoS (Quality of Service)

When a port on an Ethernet switch becomes oversubscribed, its egress

queues contain more packets than the port can handle in a timely manner. In this

situation, the port may be forced to delay the transmission of some packets, resulting in

the delay of packets reaching their destinations. A port may be forced to delay

transmission of packets while it handles other traffic, and, in some situations, some

packets destined to be forwarded to an oversubscribed port from other switch ports

may be discarded.

Minor delays are often of no consequence to a network or its performance. But there

are applications, referred to as delay or time sensitive applications, which can be

impacted by packet delays. Voice transmission and video conferences are two examples.

If packets carrying data in either of these cases are delayed from reaching their

destination, the audio or video quality may suffer.

This is where Cost of Service (CoS) is of value. It allows you to manage the flow of traffic

through a switch by having the switch ports give higher priority to some packets, such as

delay sensitive traffic, over other packets. This is referred to as prioritizing traffic.

CoS

Set CoS priority settings

QoS > CoS

Note: Before mapping the CoS priorities and the egress queues, you must disable the

Jumbo frame parameter on each port. When Jumbo frames are enabled, COS cannot be

enabled.

1. Log into your switch management page (see “Access your switch management page”

on page 5).

2. Click on QoS and click on CoS.

3. In QoS Status, select Enabled and then click Apply.

 For each Priority who’s Queue ID you want to change, click on the CoS Table

(1-7, Ignore) radio button that applies to your configuration.

4. Review the settings. Click Apply to save the settings.

5. At the bottom of the left hand panel, click Save.

6. Select the Config you would like to save the settings to, click Save Settings to Flash,

then click OK.

Note: This step saves all configuration changes to the NV-RAM to ensure that if the

switch is rebooted or power cycled, the configuration changes will still be applied.