Enhancements in Release F.04.08

Configuring Port-Based Priority for Incoming Packets

Outbound Port Queues and Packet Priority Settings

Series 2500 switch ports use two outbound port queues, Normal and High. As described below, these two queues map to the eight priority settings specified in the 802.1p standard.

Table 8. Mapping Priority Settings to Device Queues

802.1p Priority Settings Used

Series 2500

Queue Assignment in Downstream Devices With:

In Tagged VLAN Packets

Outbound

8 Queues

4 Queues

3 Queues*

2 Queues

 

 

Port Queues

 

 

 

 

 

 

 

 

 

 

 

 

 

1

(low)

Normal

1

1

1

1

2

(low)

Normal

2

1

1

1

0

(normal priority)

Normal

3

 

 

1

2

2

3

 

Normal

4

2

2

1

4

 

 

5

 

 

 

 

High

3

3

2

5

 

High

6

3

3

2

6

 

High

7

 

3

2

 

4

7

(high priority)

High

8

4

3

2

 

 

 

 

 

 

 

* ProCurve Switch 4100GL ports use three outbound priority queues.

For example, suppose you have configured port 10 to assign a priority level of 1 (low) to the (untagged) inbound packets it receives:

■An untagged packet coming into the switch on port 10 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.

■A tagged packet with any 802.1p priority setting (0 - 7) coming into the switch on port 10 and leaving the switch through any other port configured as a tagged VLAN member would keep its original priority setting (regardless of the port-based priority setting on port 10).

Note

For a packet to carry a given 802.1p priority level from end-to-end in a network, the VLAN for the packet must be configured as tagged on all switch-to-switch links. Otherwise the tag is removed and the 802.1p priority is lost as the packet moves from one switch to the next.

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