HP ProCurve 5300xl Series Management Manual page 322

Quality of Service (QoS): Managing Bandwidth More Effectively
Using QoS Classifiers To Configure Quality of Service for Outbound Traffic
Table 8-12. How the Switch Uses the ToS Configuration
Outbound Port
IP Packet Sent Out Depending on the value of the IP
an Untagged Port Precedence bits in the packet's
in a VLAN ToS field, the packet will go to one
of four outbound port queues in
the switch:
1 - 2 = low priority
0 - 3 = normal priority
4 - 5 = high priority
6 - 7 = high priority
IP Packet Sent Out Same as above, plus the IP Prece- Same as above, plus the Priority value (0 - 7) will be used to set
an Untagged Port dence value (0 - 7) will be used to a corresponding 802.1p priority in the VLAN tag carried by the
in a VLAN set a corresponding 802.1p priority packet to the next downstream device. Where No-override is the
in the VLAN tag carried by the
packet to the next downstream
device. Refer to table 8-13, below.
8-48
IP Precedence
(Value = 0 - 7)
Table 8-13. ToS IP-Precedence Bit Mappings to 802.1p Priorities
ToS Byte IP Corresponding Service Priority Level
Precedence Bits 802.1p Priority
000
001
002
003
004
005
006
007
ToS Option:
Differentiated Services
For a given packet carrying a ToS codepoint that the switch has
been configured to detect:
• Change the codepoint according to the configured policy and
assign the 802.1p priority specified for the new codepoint in
the DSCP Policy Table (page 8-62).
• Do not change the codepoint, but assign the 802.1p priority
specified for the existing codepoint in the DSCP Policy Table
(page 8-62).
Depending on the 802.1p priority used, the packet will leave the
switch through one of the following queues:
1 - 2 = low priority
0 - 3 = normal priority
4 - 5 = high priority
6 - 7 = high priority
If No-override (the default) has been configured for a specified
codepoint, then the packet is not prioritized by ToS and, by
default, is sent to the "normal priority" queue.
assigned priority, the VLAN tag carries a "0" (normal priority)
802.1p setting if not prioritized by other QoS classifiers.
1 Lowest
2 Low
0 Normal
3
4
5
6
7 Highest