ZyXEL Communications NWA-3550, User Manual

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Chapter 9 SSID Screen
NWA-3500/NWA-3550 User’s Guide
151
typical data packet sizes. Note that the figures given are merely examples - sizes
may differ according to application and circumstances.
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.
9.3.3 ATC+WMM
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
Section 9.2.1 on page 148 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 Section 9.3.3.1 on page
152 ).
• automatically prioritize all packets going from your wireless network to the
wired network (see Section 9.3.3.2 on page 152 ).
Table 32 Typical Packet Sizes
APPLICATION
TIME
SENSITIVITY
TYPICAL PACKET
SIZE (BYTES)
Voice over IP (SIP) High < 250
Online Gaming High 60 ~ 90
Web browsing (http) Medium 300 ~ 600
FTP Low 1500
Table 33 Automatic Traffic Classifier Priorities
PACKET SIZE
(BYTES)
ATC PRIORITY
1 ~ 250 ATC_High
250 ~ 1100 ATC_Medium
1100 + ATC_Low