User`s guide

Chapter 21 Bandwidth Management
P-2602HWUDL-D 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 224 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
Internet
Subnet A
Subnet B
Subnet A: 320 Kbps
Subnet B: 320 Kbps
LAN
WAN