Home: Configuring/Enabling QoS

These steps describe how to configure quality of service (QoS) on your access point. With this feature, you can provide preferential treatment to certain traffic at the expense of others. Without QoS, the access point offers best-effort service to each packet, regardless of the packet contents or size.

Typically, networks operate on a best-effort delivery basis, which means that all traffic has equal priority and an equal chance of being delivered in a timely manner. When congestion occurs, all traffic has an equal chance of being dropped.

When you configure QoS on the access point, you can select specific network traffic, prioritize it according to its relative importance, and use congestion-management and congestion-avoidance techniques to provide preferential treatment. Implementing QoS in your wireless LAN makes network performance more predictable and bandwidth utilization more effective.

When you configure QoS, you create QoS policies and apply the policies to the VLANs configured on your access point. If you do not use VLANs on your network, you can apply your QoS policies to the access point's Ethernet and radio ports.

QoS is disabled by default. Before configuring QoS on your access point, you should be aware of this information:

• The most important guideline in QoS deployment is to be familiar with the traffic on your wireless LAN. If you know the applications used by wireless client devices, the applications' sensitivity to delay, and the amount of traffic associated with the applications, you can configure QoS to improve performance.
• QoS does not create additional bandwidth for your wireless LAN; it helps control the allocation of bandwidth. If you have plenty of bandwidth on your wireless LAN, you might not need to configure QoS.

Follow these steps to configure QoS on your access point.

1. If you use VLANs on your wireless LAN, make sure the necessary VLANs are configured on your access point before configuring QoS.
2. On the navigation menu, click Services to go to the Services Summary screen.
3. From the expanded Services menu, click QoS to go to the QoS Policies screen.
   
   
   
   
4. With <NEW> selected in the Create/Edit Policy field, type a name for the QoS policy in the Policy Name entry field. The name can contain up to 25 alphanumeric characters. Do not include spaces in the policy name.
5. If the packets you need to prioritize contain IP precedence information in the IP header TOS field, select an IP precedence classification from the IP Precedence drop-down menu. Menu selections include:
   • Routine (0)
   • Priority (1)
   • Immediate (2)
   • Flash (3)
   • Flash Override (4)
   • Critic/CCP (5)
   • Internet Control (6)
   • Network Control (7)
6. From the Apply Class of Service drop-down menu, select the class of service that the access point will apply to packets of the type that you selected from the IP Precedence menu. The access point matches your IP Precedence selection with your class of service selection. Settings in the Apply Class of Service menu include:
   • Best Effort (0)
   • Background (1)
   • Spare (2)
   • Excellent (3)
   • Control Lead (4)
   • Video <100ms Latency (5)
   • Voice <100ms Latency (6)
   • Network Control (7)
7. Click Add beside the Class of Service menu for IP Precedence. The classification appears in the Classifications field. To delete a classification, select it and click Delete beside the Classifications field.
8. If the packets that you need to prioritize contain IP DSCP precedence information in the IP header TOS field, select an IP DSCP classification from the IP DSCP drop-down menu. Menu selections include:
   • Best Effort
   • Assured Forwarding - Class 1 Low
   • Assured Forwarding - Class 1 Medium
   • Assured Forwarding - Class 1 High
   • Assured Forwarding - Class 2 Low
   • Assured Forwarding - Class 2 Medium
   • Assured Forwarding - Class 2 High
   • Assured Forwarding - Class 3 Low
   • Assured Forwarding - Class 3 Medium
   • Assured Forwarding - Class 3 High
   • Assured Forwarding - Class 4 Low
   • Assured Forwarding - Class 4 Medium
   • Assured Forwarding - Class 4 High
   • Class Selector 1
   • Class Selector 2
   • Class Selector 3
   • Class Selector 4
   • Class Selector 5
   • Class Selector 6
   • Class Selector 7
   • Expedited Forwarding
9. Use the Apply Class of Service drop-down menu to select the class of service that the access point will apply to packets of the type that you selected from the IP DSCP menu. The access point matches your IP DSCP selection with your class of service selection.
10. Click Add beside the Class of Service menu for IP DSCP. The classification appears in the Classifications field.
11. If you need to prioritize the packets from Spectralink phones (IP Protocol 119) on your wireless LAN, use the Apply Class of Service drop-down menu to select the class of service that the access point will apply to Spectralink phone packets. The access point matches Spectralink phone packets with your class of service selection.
12. Click Add beside the Class of Service menu for IP Protocol 119. The classification appears in the Classifications field.
13. If you want to set a default classification for all packets on a VLAN, use the Apply Class of Service drop-down menu to select the class of service that the access point will apply to all packets on a VLAN. The access point matches all packets with your class of service selection.
14. Click Add beside the Class of Service menu for Default classification for packets on the VLAN. The classification appears in the Classifications field.
15. When you finish adding classifications to the policy, click Apply under the Apply Class of Service drop-down menus. To cancel the policy and reset all fields to defaults, click Cancel below the Apply Class of Service drop-down menus. To delete the entire policy, click Delete below the Apply Class of Service drop-down menus.
16. Use the Apply Policies to Interface/VLANs drop-down menus to apply policies to the access point Ethernet and radio ports. If VLANs are configured on the access point, drop-down menus for each VLAN’s virtual ports appear in this section. If VLANs are not configured on the access point, drop-down menus for each interface appear.
17. Click Apply at the bottom of the page to apply the policies to the access point ports.