Manage Radio Frequency Optimization

You can enable or disable these RF Optimization parameters:

  • Smart Client Load Balancing
  • Smart Steering
  • Min Association RSSI
  • Band Steering
  • Proxy ARP and NDP
  • Broadcast and Multicast Control
  • IGMP Snooping

Manage Smart Client Load Balancing

Smart Client Load Balancing efficiently manages and distributes the clients across APs within the same band. For example, in high-density environments, a client may find more than one AP in the vicinity with good signal strength. As a result, a number of clients may end up connecting to an AP with the best signal strength causing performance issues and degradation of the wireless network. Smart Client Load Balancing prevents this issue.

Background Scanning must be enabled on an AP radio for Smart Client Load Balancing. Enabling Smart Client Load Balancing also enables Smart Steering and Minimum Association RSSI, but you can disable these features if you do not want to use them.

Smart Steering

Smart Steering addresses the problems that occur when a roaming client moves away from the AP that it is currently associated with and stays connected to the AP although there is a better AP in the vicinity. Smart Steering proactively steers the client to a better AP for a better connection.

When Smart Steering is enabled on the SSID profile associated with a device, the values for the Roam Initiation Threshold Interval and the Roam Initiation Threshold Packets configured in Device Template > Radio Advanced Settings are used to decide if the AP can allow or reject a client connection. The Smart Steering RSSI Threshold is 10 dBm less than the Steering RSSI Threshold in Client Steering Common Parameters.

If the signal strength is less than the Smart Steering RSSI Threshold, and the number of packets received are greater than the Roam Initiation Threshold Packets in the time interval specified in the Roam Initiation Threshold Interval, the AP disconnects the client. For details on the Smart Steering parameters, refer to Smart Steering Parameters under Radio Advanced Settings in the Manage Device Templates section.

We recommend that you disable band steering if clients experience connection problems because of Smart Steering, or high RSSI coverage is not planned for your facility, or if there is voice traffic on the wireless network.

To enable smart steering:

  1. Select the Smart Steering check box in RF Optimizations.
  2. Click Save.

When you enable Smart Steering in your SSID profile, you must configure Smart Steering parameters as well as the minimum association RSSI parameters in the advanced radio settings of a device template. If these parameters are not configured, the default values specified for these parameters in the SSID profile are used by the device.

To configure Smart Steering parameters:

  1. Select Configuration > Device Configuration > Device Template > Radio Advanced Setting > Smart Steering.
  2. Specify the Roaming Initiation Threshold Interval and Roaming Initiation Threshold Packets.
  3. Click Save.

Minimum Association RSSI Parameters

You can define the minimum RSSI required for a client to associate to an AP. This helps with roaming issues where a roaming client may try to connect to an AP several times because of the weak signal. If the client tries to connect too many times, the client may be classified as a desperate client and could be allowed to associate with the AP.

Band Steering

When you configure an SSID in both the 2.4 GHz and 5 GHz bands, clients in one of these bands can be steered towards the other band to balance the load on the AP. Band Steering helps to evenly distribute the wireless clients between the two bands. It is available in dual-radio AP models.

Band steering works in a bi-directional manner, steering clients from a 2.4 GHz to a 5 GHz radio, or from a 5 GHz to a 2.4 GHz radio to balance the load on the AP.

Clients connecting to an AP are steered from 2.4 GHz to 5 GHz or 5 GHz to 2.4 GHz when these conditions are satisfied:

  • Band steering is enabled on the SSID profile that the client is associated with
  • Client RSSI is equal or above the RSSI threshold
  • The number of clients on one radio is not greater than clients on the other radio. The Smart Client Load Balancing threshold defined in the device template Radio Advanced Settings is also a factor.

When you enable band steering, you must specify the RSSI threshold of the clients. This is required because clients with weak signal strength cannot operate effectively in the 5 GHz band and should not be steered even if they are capable of operating in 5 GHz.

To configure band steering:

  1. Select the Band steering check box in RF Optimizations.
  2. Specify the RSSI Threshold of the client.
  3. Click Save.

Enforce Steering

When you select the Enforce Steering option, 802.11ac APs can process additional management packets to make sure a client is always disconnected from the 2.4 GHz radio and steered to the 5 GHz radio when the client reconnects to the AP. This option is ignored for APs that do not support 802.11ac.

Steering decisions are based on the RSSI Threshold in the SSID Profile and the Smart Client Load Balancing thresholds configured in the Device Template.

802.11k and 802.11v Roaming

The 802.11k and 802.11v protocols work with the existing 802.11r fast roaming protocol to enhance client roaming between access points. This helps provide seamless roaming between access points to prevent interruptions to streaming applications.

  • 802.11k provides wireless clients with nearby AP information that helps clients make faster roaming decisions.
  • 802.11v enables an AP to warn an associated client that the client will be disconnected from this AP because there are APs with a stronger signal to connect to.

To enable the 11kv Neighbour List, select the check box. You can also optionally enable Neighbour List Dual Band to search both bands.

To enable 11v BSS Transition, select the check box.

If you enable 11v BSS Transition, you must enable the Disassociation Imminent and configure it in the Disassociation Timer field. This is the time after which the client will be disconnected from the AP. The Disassociation Timer is expressed in number of beacon intervals. The range of the Disassociation Timer should be between 10 to 3000 TBTT (Target Beacon Transmission Time). When the Disassociation Timer reaches zero, then the client can be disassociated based on the Force Disconnection setting.

You can select Force Disconnection to forcefully disconnect the client after the disassociation timer expires. The client will be disconnected even if it responds with a negative BSS transition response. If Force Disconnection is disabled, the AP waits for the client to disconnect on its own.

You must enable background scanning on the radio in the Device Template if you want to enable 802.11k and 802.11v. This is not required for APs with three radios.

Manage Proxy ARP and NDP

When you enable Proxy ARP and NDP, the AP filters downstream ARP (IPv4) and NDP (IPv6) packets and also responds as appropriate on behalf of wireless clients to conserve wireless bandwidth.

Enabling Proxy ARP and NDP allows you to disable DGAF.

Disable DGAF

If you enable Proxy ARP and NDP, then you can disable DGAF. Disable DGAF starts proxy ARP for IPv4 and proxy NDP for IPv6. It also drops all Multicast and Broadcast packets in the transmit path.

You cannot enable Broadcast and Multicast Control and IGMP Snooping if you have disabled DGAF.

Manage Broadcast and Multicast Control

Many enterprise deployments prevent excessive and unnecessary broadcast and multicast traffic from being forwarded from the wired side to the wireless side of an access point.

Applications that require broadcast:

  • ARP
  • DHCP
  • RARP

Application that require Multicast:

  • Video
  • Bonjour

You can block broadcast and multicast packets on your wireless network and create exemptions for specific applications.

  • Enable Block Wireless to Wired to block broadcast and multicast traffic from the wireless side to the wired side.
  • Enable Allow Bonjour to allow the Apple Bonjour protocol for services such as Apple AirPlay and AirPrint.

Exemption List

You can create an exemption list for applications that must be allowed to use broadcast/multicast packets.

  • Type a Name for the rule.
  • Specify the Destination MAC address.
  • Select the protocol from UDP, ANY, or OTHER.
  • Select the Ether type from IPv4, IPv6, or OTHER.
  • Specify the Port.
  • Click Add.

If Ether type is set to OTHER, the corresponding value is the last four alphanumeric values of the Ether type that you want to specify. For example, for APPLETALK Ether type (0x809B), you must specify the value as 809B.

Some of the most common types are:

Name Ether Type Value
aarp AARP (0x80F3) 80F3
appletalk APPLE TALK (0x809B) 809B
arp ARP (0x0806) 0806
ip IP (0x0800) 0800
ipv6 IPV6 (0x86DD) 86DD
ipx IPX (0x8137) 8137
mint MINT (0x8783) 8783
rarp RARP Ether Type (0x8035) 8035
wisp WISP Ether Type (0x8783) 8783

Manage IGMP Snooping

IGMP Snooping listens to IGMP (Internet Group Management Protocol) network traffic to track connections that require IP multicast streams such as video streaming traffic. Enable snooping for an SSID to block multicast packets if no client joins the multicast group to optimize streaming traffic.

You can create exceptions for specific IP addresses. Packets with multicast IP addresses in the exception list are not dropped even if no client joins the multicast group.

IGMP Snooping Exception List

You can enter up to 30 IP addresses in the IGMP Snooping Exception list text box.

The packets with multicast IP addresses that are mentioned in the exception list are not dropped even if no client joins the multicast group. They are not converted to Unicast even if Convert Multicast to Unicast is enabled.

Snoop Timeout

You can specify a timeout for snooping only if Convert Multicast to Unicast is enabled. You can specify the value within a range of 0 to 480 minutes. The default timeout value is 5 minutes.

  • If a client does not send any IGMP packets to the group for an interval specified in the timeout, then the client is removed from the group.
  • If a group receives no Multicast packet for the specified timeout period, and if no client sends any join/report response, then the entire group is removed.
  • If all clients leave the group, then the group is removed.

Convert Multicast to Unicast

Multicast traffic can be converted to unicast traffic after it passes IGMP snooping verifications. This option converts layer 2 multicast MAC addresses to layer 2 unicast MAC addresses and optimizes multicast traffic on the network. IGMP Snooping exceptions are not converted to Unicast even if Convert Multicast to Unicast is enabled.

Enabling conversion of multicast traffic to unicast through the IGMP snooping capability is not supported when Application Visibility is enabled.

Tag Packets with Selected Priority

You can also tag packets with a selected priority for the packets that are converted from multicast to unicast. In this case, the unicast packets will have the specified QoS Priority. The allowed values are:

  • Default
  • Background
  • Best Effort
  • Video
  • Voice

The default priority is Default. This indicates that the packets will have the priority specified in the QoS setting in the Traffic Shaping and QoS section of the SSID Profile.