Example for Configuring Priority Mapping

Networking Requirements

As shown in Figure 1, SwitchA and SwitchB are connected to the router, and enterprises branches 1 and 2 can access the network through LSW1 and LSW2

Enterprise branch 1 requires better QoS guarantee. Therefore, the DSCP priority of data packets from enterprise branch 1 is mapped to 45, while the DSCP priority of those from enterprise branch 2 is mapped to 30. The Switch trusts DSCP priorities of packets. When congestion occurs, the Switch first processes packets of higher DSCP priority.

Figure 1 Networking diagram of priority mapping

Configuration Roadmap

The configuration roadmap is as follows:

Create VLANs and configure interfaces so that enterprise branches 1 and 2 can access the network.
Configure priority mapping to map the DSCP priority of data packets from enterprise branch 1 to 45, and the DSCP priority of those from enterprise branch 2 to 30.

Procedure

Configure SwitchA.

# Create VLAN 100.

<HUAWEI> system-view
[HUAWEI] sysname SwitchA
[SwitchA] vlan batch 100

# Set the link type of GE 0/0/1 and GE 0/0/2 to trunk and add them to VLAN 100.

[SwitchA] interface gigabitethernet 0/0/1
[SwitchA-GigabitEthernet0/0/1] port link-type trunk
[SwitchA-GigabitEthernet0/0/1] port trunk allow-pass vlan 100
[SwitchA-GigabitEthernet0/0/1] quit
[SwitchA] interface gigabitethernet 0/0/2
[SwitchA-GigabitEthernet0/0/2] port link-type trunk
[SwitchA-GigabitEthernet0/0/2] port trunk allow-pass vlan 100
[SwitchA-GigabitEthernet0/0/2] quit

# Configure interfaces to trust DSCP priorities of packets.

[SwitchA] interface gigabitethernet 0/0/1
[SwitchA-GigabitEthernet0/0/1] trust dscp
[SwitchA-GigabitEthernet0/0/1] quit
[SwitchA] interface gigabitethernet 0/0/2
[SwitchA-GigabitEthernet0/0/2] trust dscp
[SwitchA-GigabitEthernet0/0/2] quit

# Configure priority mapping.

[SwitchA] qos map-table dscp-dscp
[SwitchA-dscp-dscp] input 0 to 63 output 45 
[SwitchA-dscp-dscp] quit

Configure SwitchB.

# Create VLAN 200.

<HUAWEI> system-view
[HUAWEI] sysname SwitchB
[SwitchB] vlan batch 200

# Set the link type of GE 0/0/1 and GE 0/0/2 to trunk and add them to VLAN 200.

[SwitchB] interface gigabitethernet 0/0/1
[SwitchB-GigabitEthernet0/0/1] port link-type trunk
[SwitchB-GigabitEthernet0/0/1] port trunk allow-pass vlan 200
[SwitchB-GigabitEthernet0/0/1] quit
[SwitchB] interface gigabitethernet 0/0/2
[SwitchB-GigabitEthernet0/0/2] port link-type trunk
[SwitchB-GigabitEthernet0/0/2] port trunk allow-pass vlan 200
[SwitchB-GigabitEthernet0/0/2] quit

# Configure interfaces to trust DSCP priorities of packets.

[SwitchB] interface gigabitethernet 0/0/1
[SwitchB-GigabitEthernet0/0/1] trust dscp
[SwitchB-GigabitEthernet0/0/1] quit
[SwitchB] interface gigabitethernet 0/0/2
[SwitchB-GigabitEthernet0/0/2] trust dscp
[SwitchB-GigabitEthernet0/0/2] quit

# Configure priority mapping.

[SwitchB] qos map-table dscp-dscp
[SwitchB-dscp-dscp] input 0 to 63 output 30 
[SwitchB-dscp-dscp] quit

Verify the configuration.

# View priority mapping information on SwitchA.

[SwitchA] display qos map-table dscp-dscp
Input DSCP       DSCP
------------------------
0                45
1                45
2                45
3                45
4                45
......
63               45

# View the interface configuration on SwitchA.

[SwitchA] interface gigabitethernet 0/0/1
[SwitchA-GigabitEthernet0/0/1] display this
#
interface GigabitEthernet0/0/1
 port link-type trunk
 port trunk allow-pass vlan 100
 trust dscp
#                                                                               
return   
[SwitchA-GigabitEthernet0/0/1] quit
[SwitchA] interface gigabitethernet 0/0/2
[SwitchA-GigabitEthernet0/0/2] display this
#
interface GigabitEthernet0/0/2
 port link-type trunk
 port trunk allow-pass vlan 100
 trust dscp
#                                                                               
return

# View priority mapping information on SwitchB.

[SwitchB] display qos map-table dscp-dscp
Input DSCP       DSCP
------------------------
0                30
1                30
2                30
3                30
4                30
......
63               30

# View the interface configuration on SwitchB.

[SwitchB] interface gigabitethernet 0/0/1
[SwitchB-GigabitEthernet0/0/1] display this
#
interface GigabitEthernet0/0/1
 port link-type trunk
 port trunk allow-pass vlan 200
 trust dscp
#                                                                               
return   
[SwitchB-GigabitEthernet0/0/1] quit
[SwitchB] interface gigabitethernet 0/0/2
[SwitchB-GigabitEthernet0/0/2] display this
#
interface GigabitEthernet0/0/2
 port link-type trunk
 port trunk allow-pass vlan 200
 trust dscp
#                                                                               
return

Configuration Files

SwitchA configuration file

#
sysname SwitchA
#
vlan batch 100
# 
interface GigabitEthernet0/0/1
 port link-type trunk
 port trunk allow-pass vlan 100
 trust dscp
# 
interface GigabitEthernet0/0/2
 port link-type trunk
 port trunk allow-pass vlan 100
 trust dscp
#
qos map-table dscp-dscp
  input 0 to 44 output 45
  input 46 to 63 output 45
#                                                                               
return

SwitchB configuration file

#
sysname SwitchB
#
vlan batch 200
# 
interface GigabitEthernet0/0/1
 port link-type trunk
 port trunk allow-pass vlan 200
 trust dscp
# 
interface GigabitEthernet0/0/2
 port link-type trunk
 port trunk allow-pass vlan 200
 trust dscp
#
qos map-table dscp-dscp
  input 0 to 29 output 30
  input 31 to 63 output 30
#                                                                               
return

Relevant Information

Technology Forum

QoS Issues - Issue 3 QoS Implementation - Simple Traffic Classification and Re-marking