ZyXEL Communications ZyWall USG 2000 User Manual page 445

numbers for SIP traffic. Likewise, configuring the SIP ALG to use custom port
numbers for SIP traffic also configures application patrol to use the same port
numbers for SIP traffic.
Bandwidth Management
When you allow an application, you can restrict the bandwidth it uses or even the
bandwidth that particular features in the application (like voice, video, or file
sharing) use. This restriction may be ineffective in certain cases, however, such as
using MSN to send files via P2P.
The application patrol bandwidth management is more flexible and powerful than
the bandwidth management in policy routes. Application patrol controls TCP and
UDP traffic. Use policy routes to manage other types of traffic (like ICMP).
Note: Bandwidth management in policy routes has priority over application patrol
bandwidth management. It is recommended to use application patrol instead of
policy routes to manage the bandwidth of TCP and UDP traffic.
Connection and Packet Directions
Application patrol looks at the connection direction, that is from which zone the
connection was initiated and to which zone the connection is going.
A connection has outbound and inbound packet flows. The ZyWALL controls the
bandwidth of traffic of each flow as it is going out through an interface or VPN
tunnel.
• The outbound traffic flows from the connection initiator to the connection
responder.
• The inbound traffic flows from the connection responder to the connection
initiator.
For example, a LAN to WAN connection is initiated from LAN and goes to the WAN.
• Outbound traffic goes from a LAN zone device to a WAN zone device. Bandwidth
management is applied before sending the packets out a WAN zone interface on
the ZyWALL.
ZyWALL USG 2000 User's Guide
Chapter 29 Application Patrol
445