ZyXEL Communications unified security gateway User Manual
Chapter 28 Bandwidth Management
ZyWALL USG 20/20W User’s Guide
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Outbound and Inbound Bandwidth Limits
You can limit an application’s outbound or inbound bandwidth. This limit keeps the
traffic from using up too much of the out-going interface’s bandwidth. This way
you can make sure there is bandwidth for other applications. When you apply a
bandwidth limit to outbound or inbound traffic, each member of the out-going
zone can send up to the limit. Take a LAN1 to WAN policy for example.
traffic from using up too much of the out-going interface’s bandwidth. This way
you can make sure there is bandwidth for other applications. When you apply a
bandwidth limit to outbound or inbound traffic, each member of the out-going
zone can send up to the limit. Take a LAN1 to WAN policy for example.
• Outbound traffic is limited to 200 kbps. The connection initiator is on the LAN1
so outbound means the traffic traveling from the LAN1 to the WAN. Each of the
WAN zone’s two interfaces can send the limit of 200 kbps of traffic.
• Inbound traffic is limited to 500 kbs. The connection initiator is on the LAN1 so
inbound means the traffic traveling from the WAN to the LAN1.
Figure 279 LAN1 to WAN, Outbound 200 kbps, Inbound 500 kbps
Bandwidth Management Priority
• The ZyWALL gives bandwidth to higher-priority traffic first, until it reaches its
configured bandwidth rate.
• Then lower-priority traffic gets bandwidth.
• The ZyWALL uses a fairness-based (round-robin) scheduler to divide bandwidth
• The ZyWALL uses a fairness-based (round-robin) scheduler to divide bandwidth
among traffic flows with the same priority.
• The ZyWALL automatically treats traffic with bandwidth management disabled
as priority 7 (the lowest priority).
Maximize Bandwidth Usage
Maximize bandwidth usage allows applications with maximize bandwidth usage
enabled to “borrow” any unused bandwidth on the out-going interface.
enabled to “borrow” any unused bandwidth on the out-going interface.
After each application gets its configured bandwidth rate, the ZyWALL uses the
fairness- based scheduler to divide any unused bandwidth on the out-going
interface amongst applications that need more bandwidth and have maximize
bandwidth usage enabled.
fairness- based scheduler to divide any unused bandwidth on the out-going
interface amongst applications that need more bandwidth and have maximize
bandwidth usage enabled.
Inbound
Outbound
500 kbps
200 kbps