HP 6400cl, Management Manual, Page: 288 / 664

Quality of Service (QoS): Managing Bandwidth More Effectively
Preparation for Configuring QoS
For more on how QoS operates with the preceding traffic types, see
‘‘Precedence Criteria for QoS Classifiers’’, on page 8-11.)
2. Select the QoS option you want to use. Table 8-8 lists the traffic types (QoS
classifiers) and the QoS options you can use for prioritizing or setting a
policy on these traffic types:
Table 8-8. Applying QoS Options to Traffic Types Defined by QoS Classifiers
QoS Options for Prioritizing Outbound Traffic QoS Classifiers
UDP/
TCP
IP
Device
IP-ToS
Precedence
IP-
DiffServ
L3
Protocol
VLAN
-ID
Source
-Port
Option 1:
Configure
802.1p
Priority
Rules Only Prioritize traffic by sending specific
packet types (determined by QoS
classifier) to different outbound port
queues on the switch.
Rely on VLAN-tagged ports to carry
packet priority as an 802.1p value to
downstream devices. Yes Yes Yes
1
Yes Yes
2
Yes Yes
Option 2:
Configure
ToS DSCP
Policies
with
802.1p
Priorities Prioritize traffic by sending specific
packet types (determined by QoS
classifier) to different outbound port
queues on the switch.
Propagate a service policy by
reconfiguring the DSCP in outbound
IP packets according to packet type.
The packet is placed in an outbound
port queue according to the 802.1p
priority configured for that DSCP
policy. (The policy assumes that
downstream devices can be
configured to recognize the DSCP in
IP packets and implement the
service policy it indicates.)
Use VLAN-tagged ports to include
packet priority as an 802.1p value to
downstream devices. Yes Yes No Yes No Yes Yes
1
In this mode the configuration is fixed. You cannot change the automatic priority assignment when using IP-ToS
Precedence as a QoS classifier.
2
Not available on the 3400cl/6400cl switches.
3. If you want 802.1p priority settings to be included in outbound packets,
ensure that tagged VLANs are configured on the appropriate downstream
links.
4. Determine the actual QoS configuration changes you will need to make
on each QoS-capable device in your network in order to implement the
desired policy. Also, if you want downstream devices to read and use
8-14