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

Priority

Outbound Port

802.1p Priority

 

 

 

 

Policy Set

Queue in the

Setting Added to

 

Queue Assignment Downstream

in HP

Procurve Switches

Tagged VLAN

 

 

 

 

TopTools

 

Packet Leaving the

 

 

 

 

 

 

Switch

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8 Queues

 

4 Queues

2 Queues

 

 

 

 

 

 

 

 

1

 

1

(low priority)

Queue 1

 

 

 

 

 

 

 

 

 

Queue 1

 

2

 

2

 

Queue 2

 

 

 

 

 

 

 

 

Normal

 

 

 

 

 

Queue 1

0

0

(normal priority)

Queue 3

 

 

 

 

 

 

 

 

 

 

 

 

Queue 2

 

3

 

3

 

Queue 4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

 

4

 

Queue 5

 

 

 

 

 

 

 

 

 

Queue 3

 

5

 

5

 

Queue 6

 

 

 

 

 

 

 

 

High

 

 

 

 

 

Queue 2

6

6

 

Queue 7

 

 

 

 

 

 

 

 

 

 

 

 

 

Queue 4

 

7

 

7

(high priority)

Queue 8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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 description of how this works.

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