Optimizing Traffic Flow with Port Controls, Port Trunking, and Port-Based Priority
downstream device. If the outbound port is not configured as a tagged member
of the VLAN, then the tag is stripped from the packet, which then exits from
the switch without a priority setting.
Outbound Port Queues and Packet Priority Settings
Ports on the HP ProCurve switches have the following outbound port queue
structure:
Switch Model
Switch 6108
Series 5300XL Switches
Series 4100GL Switches
Series 2600 Switches
Series 2500 Switches
Switches 1600M/2400M/2424M/4000M/8000M
As shown below, these port queues map to the eight priority settings specified
in the 802.1p standard.
Table 10-9. Mapping Priority Settings to Device Queues
802.1p Priority Settings Used
In Tagged VLAN Packets
1 (low)
2 (low)
0 (normal priority)
3
4
5
6
7 (high priority)
For example, suppose you have configured port A10 to assign a priority level
of 1 (low):
■
An untagged packet coming into the switch on port A10 and leaving the
switch through any other port configured as a tagged VLAN member
would leave the switch as a tagged packet with a priority level of 1.
Configuring Port-Based Priority for Incoming Packets
Outbound
Port Queues
4
4
3
4
2
2
Switches with
Queue Assignment in Downstream Devices
3 Outbound
With:
Port Queues
4 Queues
Low
1
Low
1
Normal
2
N
ormal
2
H
igh
3
H
igh
3
H
igh
4
High
4
8 Queues
2 Queues
1
1
2
1
3
1
4
1
5
2
6
2
7
2
8
2
10-35