DGFV338 ProSafe Wireless ADSL Modem VPN Firewall Router Reference Manual
Security and Firewall Protection 4-19
v1.0, April 2007
Quality of Service (QoS) Priorities
This setting determines the priority of a service, which in turn, determines the quality of that
service for the traffic passing through the firewall. The user can change this priority for Outbound
Services only.
The QoS priority definition for a service determines the IP packets queue for outbound traffic
passing through the ProSafe DGFV338 for this service. The priorities are defined by “Type of
Service (TOS) in the Internet Protocol Suite” standards, RFC 1349. The router marks the Type Of
Service (TOS) field as defined below:
•Normal-Service: No special priority is given to the traffic. The IP packets for services with
this priority are marked with a ToS value of 0.
•Minimize-Cost: Used when the data must be transferred over a link that has a low
transmission cost. The IP packets for this service priority are marked with a ToS value of 1.
•Maximize-Reliability: Used when data needs to travel to the destination over a reliable link
with little or no retransmission. The IP packets for this service priority are marked with a ToS
value of 2.
•Maximize-Throughput: Used when the volume of data transferred during an interval is
important even though it may have a hig h link latency. The IP packets for this service priority
are marked with a ToS value of 4.
Figure 4-14
Outbound Rules Add Screen
QoS Priority