ZyXEL Communications 200 Series User Manual

Chapter 27 Application Patrol

ZyWALL USG 100/200 Series User’s Guide

• Inbound traffic is limited to 500 kbs. The connection initiator is on LAN1 so inbound 

means the traffic traveling from the WAN to the LAN1. 

Figure 355   LAN 1to WAN, Outbound 200 kbps, Inbound 500 kbps 

• 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 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 allows applications with maximize bandwidth usage 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.

Unused bandwidth is divided equally. Higher priority traffic does not get a larger portion of 
the unused bandwidth.

The following sections show how bandwidth management behaves with various settings. For 
example, you configure DMZ to WAN policies for FTP servers A and B. Each server tries to 
send 1000 kbps, but the WAN is set to a maximum outgoing speed of 1000 kbps. You 
configure policy A for server A’s traffic and policy B for server B’s traffic.

Inbound

Outbound

Outbound

500 kbps

200 kbps

200 kbps