Example for Configuring Congestion Avoidance and Congestion Management
Networking Requirements
The Switch is connected to the router through GE0/0/3; the 802.1p priorities of voice, video, and data services on the Internet are 6, 5, and 2 respectively, and these services can reach users through the router and Switch, as shown in Figure 6-13. The rate of inbound interface GE0/0/3 on the Switch is greater than the rates of outbound interfaces GE0/0/1 and GE0/0/2; therefore, congestion may occur on these two outbound interfaces.
To reduce the impact of network congestion and ensure bandwidth for high-priority and delay-sensitive services, set parameters based on Table 6-3 and Table 6-4.
Service Type |
Color |
Lower Threshold (%) |
Upper Threshold (%) |
Drop Percent |
|---|---|---|---|---|
Voice |
Green |
80 |
100 |
10 |
Video |
Yellow |
60 |
80 |
20 |
Data |
Red |
40 |
60 |
40 |
Configuration Roadmap
Configure the VLAN for each interface so that devices can communicate with each other.
Create and configure a DiffServ domain on the Switch, map packets of 802.1p priorities to PHBs and colors of packets, and bind the DiffServ domain to an inbound interface on the Switch.
Create a WRED drop profile on the Switch and apply the WRED drop profile on an outbound interface.
Set scheduling parameters of queues of different CoS on outbound interfaces of the Switch.
Procedure
- Configure the VLAN for each interface so that the devices can communicate with each other.
<HUAWEI> system-view [HUAWEI] sysname Switch [Switch] vlan batch 2 5 6 [Switch] interface gigabitethernet 0/0/1 [Switch-GigabitEthernet0/0/1] port link-type trunk [Switch-GigabitEthernet0/0/1] port trunk allow-pass vlan 2 5 6 [Switch-GigabitEthernet0/0/1] quit [Switch] interface gigabitethernet 0/0/2 [Switch-GigabitEthernet0/0/2] port link-type trunk [Switch-GigabitEthernet0/0/2] port trunk allow-pass vlan 2 5 6 [Switch-GigabitEthernet0/0/2] quit [Switch] interface gigabitethernet 0/0/3 [Switch-GigabitEthernet0/0/3] port link-type trunk [Switch-GigabitEthernet0/0/3] port trunk allow-pass vlan 2 5 6 [Switch-GigabitEthernet0/0/3] quit
- Configure priority mapping based on simple traffic classification.
For the priority mapping configuration of the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-S, S5731S-H, S5732-H, S5735-L, S5735S-L, S5735S-L-M, S5735-S, S5735S-S, S5735-S-I, S6720-EI, S6720S-EI, S6720-HI, S6730-H, S6730S-H, S6730-S, and S6730S-S, refer to Configuring Priority Mapping. For the priority mapping configuration of the S2720-EI, S5720-LI, S5720S-LI, S5720-SI, S5720S-SI, S5720I-SI, S5730-SI, S5730S-EI, S6720-LI, S6720S-LI, S6720-SI, and S6720S-SI, refer to Configuring Priority Mapping.
The configuration in this step is applicable to the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S.
# Create DiffServ domain ds1, map packets of 802.1p priorities 6, 5, and 2 to PHBs EF, AF3, and AF1, and color packets as green, yellow, and red.
[Switch] diffserv domain ds1 [Switch-dsdomain-ds1] 8021p-inbound 6 phb ef green [Switch-dsdomain-ds1] 8021p-inbound 5 phb af3 yellow [Switch-dsdomain-ds1] 8021p-inbound 2 phb af1 red [Switch-dsdomain-ds1] quit
# Bind incoming interface GE0/0/3 on the Switch to DiffServ domain ds1.
[Switch] interface gigabitethernet 0/0/3 [Switch-GigabitEthernet0/0/3] trust upstream ds1 [Switch-GigabitEthernet0/0/3] trust 8021p inner [Switch-GigabitEthernet0/0/3] quit
- Configure congestion avoidance.
# Create drop profile wred1 on the Switch and set parameters of packets of three colors.
[Switch] drop-profile wred1 [Switch-drop-wred1] color green low-limit 80 high-limit 100 discard-percentage 10 [Switch-drop-wred1] color yellow low-limit 60 high-limit 80 discard-percentage 20 [Switch-drop-wred1] color red low-limit 40 high-limit 60 discard-percentage 40 [Switch-drop-wred1] quit
# Apply drop profile wred1 on outbound interfaces GE0/0/1 and GE0/0/2 of the Switch.
[Switch] interface gigabitethernet 0/0/1 [Switch-GigabitEthernet0/0/1] qos wred wred1 [Switch-GigabitEthernet0/0/1] qos queue 5 wred wred1 [Switch-GigabitEthernet0/0/1] qos queue 3 wred wred1 [Switch-GigabitEthernet0/0/1] qos queue 1 wred wred1 [Switch-GigabitEthernet0/0/1] quit [Switch] interface gigabitethernet 0/0/2 [Switch-GigabitEthernet0/0/2] qos wred wred1 [Switch-GigabitEthernet0/0/2] qos queue 5 wred wred1 [Switch-GigabitEthernet0/0/2] qos queue 3 wred wred1 [Switch-GigabitEthernet0/0/2] qos queue 1 wred wred1 [Switch-GigabitEthernet0/0/2] quit
- Configure congestion management.
# Set scheduling parameters of queues of different CoS on outbound interfaces GE0/0/1 and GE0/0/2 of the Switch.
[Switch] interface gigabitethernet 0/0/1 [Switch-GigabitEthernet0/0/1] qos drr [Switch-GigabitEthernet0/0/1] qos queue 5 drr weight 0 [Switch-GigabitEthernet0/0/1] qos queue 3 drr weight 100 [Switch-GigabitEthernet0/0/1] qos queue 1 drr weight 50 [Switch-GigabitEthernet0/0/1] quit [Switch] interface gigabitethernet 0/0/2 [Switch-GigabitEthernet0/0/2] qos drr [Switch-GigabitEthernet0/0/2] qos queue 5 drr weight 0 [Switch-GigabitEthernet0/0/2] qos queue 3 drr weight 100 [Switch-GigabitEthernet0/0/2] qos queue 1 drr weight 50 [Switch-GigabitEthernet0/0/2] quit
- Verify the configuration.
# Check the configuration of DiffServ domain ds1.
[Switch] display diffserv domain name ds1 diffserv domain name:ds1 8021p-inbound 0 phb be green 8021p-inbound 1 phb af1 green 8021p-inbound 2 phb af1 red 8021p-inbound 3 phb af3 green 8021p-inbound 4 phb af4 green 8021p-inbound 5 phb af3 yellow 8021p-inbound 6 phb ef green 8021p-inbound 7 phb cs7 green 8021p-outbound be green map 0 ......# Check the configuration of drop profile wred1.
[Switch] display drop-profile name wred1 Drop-profile[1]: wred1 Queue depth : default Color Low-limit High-limit Discard-percentage - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Green 80 100 10 Yellow 60 80 20 Red 40 60 40 Non-tcp 100 100 100 -----------------------------------------------------------------
Only the display information of the S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-HI, S6730-H, S6730S-H, S6730-S, and S6730S-S contains the Queue depth field.
The display information of the S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-HI, S6730-H, S6730S-H, S6730-S, and S6730S-S does not contain the Non-tcp field.
Configuration Files
Switch configuration file
# sysname Switch # vlan batch 2 5 to 6 # diffserv domain ds1 8021p-inbound 2 phb af1 red 8021p-inbound 5 phb af3 yellow 8021p-inbound 6 phb ef green # drop-profile wred1 color green low-limit 80 high-limit 100 discard-percentage 10 color yellow low-limit 60 high-limit 80 discard-percentage 20 color red low-limit 40 high-limit 60 discard-percentage 40 # interface GigabitEthernet0/0/1 port link-type trunk port trunk allow-pass vlan 2 5 to 6 qos drr qos queue 1 drr weight 50 qos queue 3 drr weight 100 qos queue 5 drr weight 0 qos wred wred1 qos queue 1 wred wred1 qos queue 3 wred wred1 qos queue 5 wred wred1 # interface GigabitEthernet0/0/2 port link-type trunk port trunk allow-pass vlan 2 5 to 6 qos drr qos queue 1 drr weight 50 qos queue 3 drr weight 100 qos queue 5 drr weight 0 qos wred wred1 qos queue 1 wred wred1 qos queue 3 wred wred1 qos queue 5 wred wred1 # interface GigabitEthernet0/0/3 port link-type trunk port trunk allow-pass vlan 2 5 to 6 trust upstream ds1 trust 8021p inner # return