Specifications

Chapter 29 qos Commands
The qos commands define and display Quality of Service (QOS) parameters. Use the
command to classify Layer 2, Layer 3, and Layer 4 traffic into the following priorities:
•control
•high
•medium
•low
By assigning priorities to network traffic, you can ensure that critical traffic will reach
its destination even if the exit ports for the traffic are experiencing greater than
maximum utilization. Use the
qos set l2
,
qos set ip
, and
qos set ipx
commands
to assign priorities for Layer-2, IP, and IPX traffic respectively.
Flows
For Layer 3 (IP and IPX) traffic, you can define “flows”, blueprints or templates of IP
and IPX packet headers.
• The IP fields are source IP address, destination IP address, UDP/TCP source port,
UDP/TCP destination port, TOS (Type of Service), transport protocol (TCP or
UDP) and a list of incoming interfaces.
• The IPX fields are source network, source node, destination network, destination
node, source port, destination port, and a list of incoming interfaces.
The flows specify the contents of these fields. If you do not enter a value for a field, a
wildcard value (all values acceptable) is assumed for the field.
Precedence
A precedence from 1 – 7 is associated with each field in a flow. The SSR uses the
precedence value associated with the fields to break ties if packets match more than
one flow. The highest precedence is 1 and the lowest is 7. Here are the default
precedences of the fields:
• IP – destination port (1), destination address (2), source port (3), source IP address
(4), TOS (5), interface (6), protocol (7).
• IPX – destination network (1), source network (2), destination node (3), source node
(4), destination port (5), source port (6), interface (7).
Use the
qos precedence ip
and
qos precedence ipx
commands to change the
default precedences.
Chapter 29