TP-Link TL-SL3428 manual QoS Modes, VPT Default Mapping Table, VPT Value, Queue Number, DSCP Value

The following table contains the VPT to Queue default settings:

Table 7: VPT Default Mapping Table

VPT Value

0

1

2

3

4

5

6

7

Queue Number

2

1

1

2

3

3

4

4

Mapping of the VPT to the output queue is performed on a system-wide basis, and can be enabled or disabled per port.

Default CoS— Packets arriving untagged are assigned to a default VPT, which can be set by the user on a per port basis. Once the VPT is assigned, the packet is treated as if it had arrived with this tag. The VPT mapping to the output queue is based on the same user-defined 802.1p tag-based definitions.

DSCP — Users can configure the system to use the IP DSCP of the incoming packet to the output priority queues. The mapping of the IP DSCP to priority queue is set on a per system basis. If this mode is active, a non-IP packet is always classified to the best effort queue.

The default mapping is shown in the following table:

Table 8: DSCP Default Mapping Table

DSCP Value	Queue Number
0-15	q1 (lowest priority)
16-31	q2
32-47	q3
48-64	q4

All network traffic which is not assigned a DSCP value is forwarded with Best Effort service.

After packets are assigned to a specific queue, using the chosen classification method various services can be applied. Scheduling for output queues can be configured, including:

Strict priority

Weighted Round Robin (WRR)

Scheduling schemes are specified per system. WRR weights to the queues can be assigned in any order. For each interface or queue, the following output shaping can also be configured:

Committed Burst Size (CBS)

Committed Information Rate (CIR)

Actions for over-the-limit traffic

12.1.2 QoS Modes

The device supports the following QoS modes:

Basic QoS Mode

Advanced QoS Mode

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