HP TopTools for Hubs and Switches - Manual (Page 170)

13-14
Managing Switches
Configuring Switch Features
■ The priority queue assignment that the packet will receive in a down-
stream device that uses 802.1p priority settings.
Table 13-4. Priority Mapping Table
Criteria for Prioritizing Outbound Packets
You can configure CoS prioritization on the basis of five criteria ranked as
follows:
1. Device Priority (destination or source IP address)
2. IP Type of Service (ToS) field
3. Protocol Priority (IP, IPX, ARP, DEC LAT, AppleTalk, SNA, and NetBeui)
4. VLAN Priority
5. Incoming 802.1p Priority (present in tagged VLAN environments)
If more than one criteria is present in a packet, the highest ranked of the
criteria is used to prioritize the packet; all lower-ranked criteria are ignored.
For example, if CoS assigns high priority to “red” VLAN packets and normal
priority to IP packets, IP packets on the “red” VLAN will be set to normal
priority since Protocol Priority (third in precedence) has precedence over
VLAN priority (fourth in precedence).
The “Priority Criteria and Precedence” table provides a more detailed descrip-
tion of how this works.
Priority
Policy Set
in HP
TopTools Outbound Port
Queue in the
Procurve Switches 802.1p Priority
Setting Added to
Tagged VLAN
Packet Leaving the
Switch
Queue Assignment Downstream
8 Queues 4 Queues 2 Queues
1
Normal
1 (low priority) Queue 1
Queue 1
Queue 1
2 2 Queue 2
0 0 (normal priority) Queue 3
Queue 2
3 3 Queue 4
4
High
4 Queue 5
Queue 3
Queue 2
5 5 Queue 6
6 6 Queue 7
Queue 4
7 7 (high priority) Queue 8