ZyXEL Communications P-2602H User Manual

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Chapter 21 Bandwidth Management
P-2602H(W)(L)-DxA User’s Guide
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ATC assigns priority based on packet size, since time-sensitive applications such as Internet 
telephony (Voice over IP or VoIP) tend to have smaller packet sizes than non-time sensitive 
applications such as FTP (File Transfer Protocol). The following table shows some common 
applications, their time sensitivity, and their 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.
21.4  Subnet-based Bandwidth Management
You can create bandwidth classes based on subnets.
The following figure shows LAN subnets. You could configure one bandwidth class for 
subnet A and another for subnet B
Figure 169   Subnet-based Bandwidth Management Example
Table 117   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 118   Automatic Traffic Classifier Priorities
PACKET SIZE (BYTES)
ATC PRIORITY
1 ~ 250 
ATC_High
250 ~ 1100 
ATC_Medium
1100 + 
ATC_Low