ZyXEL Communications NWA-3550 ユーザーズマニュアル

 Chapter 8 Wireless Configuration

NWA-3500/NWA-3550 User’s Guide

When ATC is activated, the device sends traffic with smaller packets before traffic 
with larger packets if the network is congested. 

ATC assigns priority to packets as shown in the following table.

You should activate ATC on the NWA if your wireless network includes networking 
devices that do not support WMM QoS, or if you want to prioritize traffic but do not 
want to configure WMM QoS settings. 

The NWA can use a mapping mechanism to use both ATC and WMM QoS. The 
ATC+WMM function prioritizes all packets transmitted onto the wireless network 
using WMM QoS, and prioritizes all packets transmitted onto the wired network 
using ATC. See 

 for details of how to configure 

ATC+WMM.

Use the ATC+WMM function if you want to do the following: 

• enable WMM QoS on your wireless network and automatically assign a WMM 

priority to packets that do not already have one (see 

). 

• automatically prioritize all packets going from your wireless network to the 

wired network (see 

).

ATC+WMM from LAN (the wired Local Area Network) to WLAN (the Wireless Local 
Area Network) allows WMM prioritization of packets that do not already have WMM 
QoS priorities assigned. The NWA automatically classifies data packets using ATC 
and then assigns WMM priorities based on that ATC classification.

Web browsing 
(http)

Medium

300 ~ 600

FTP

Low

1500

Table 34   Automatic Traffic Classifier Priorities

1 ~ 250 

ATC_High

250 ~ 1100 

ATC_Medium

1100 + 

ATC_Low

Table 33   Typical Packet Sizes