Configuring a High-Throughput Virtual AP

With the implementation of the IEEE 802.11n standard, high-throughput can be configured to operate on the 5 GHz and/or 2.4 GHz frequency band.

The high-throughput SSID profile configures the high-throughput SSID settings. Stations are not allowed to use high-throughput with TKIP standalone encryption, although TKIP can be provided in mixed-mode BSSIDs that support high-throughput. High-throughput is disabled on a BSSID if the encryption mode is standalone TKIP or WEP.

De-aggregation of MAC Service Data Units (A-MSDUs) is supported on the 3000 Series, 7220, and the M3 controllers with a maximum frame transmission size of 4k bytes; however, this feature is always enabled and is not configurable. Aggregation is not currently supported.

For high-throughput to function on a virtual AP profile for the assigned AP group or specific AP, high-throughput must be enabled within the assigned ht-ssid-profile and the radio-profile(s) for the desired frequency band(s).

By default, high-throughput is enabled; however, the examples in this section guide you through manually creating profiles and enabling high-throughput on the 5 GHz and 2.4 GHz frequency bands to ensure proper functionality of a virtual AP profile named “ht-vap-corpnet” assigned to an existing AP group named “ht-corpnet-aps.”

For an example of 20 MHz channel versus 40 MHz channel pair configuration, see “20 MHz and 40 MHz Static Channel Assignments” on page 157.

This example includes the following tasks:



Create two high-throughput radio profiles named “ht-radioa-corpnet” and “ht-radiog-corpnet.”



Create and configure a 5 GHz radio profile named “ht-corpnet-a” and assign the high-throughput radio profile named “ht-radioa-corpnet.”



Create and configure a 2.4 GHz radio profile named “ht-corpnet-g” and assign the high-throughput radio profile named “ht-radiog-corpnet.”



Create and configure a high-throughput SSID profile named “ht-ssid-corpnet.”



Create an SSID profile named “ht-corpnet” and assign the high-throughput SSID profile named “ht-ssid-corpnet.”



Create a virtual AP profile named “ht-vap-corpnet” and assign the SSID profile named “ht-corpnet.”



Assign the required profiles to an existing AP group named “ht-corpnet-ap.”

The following procedures are presented for the WebUI and the CLI.

In the WebUI

Navigate to page.

Click for the AP group ht-corpnet-ap.

Under the Profiles list, select to display the radio profiles.

Select the

This radio profile represents activity on the 5 GHz frequency band. Since the high-throughput IEEE 802.11n standard operates on the 5 GHz and/or 2.4 GHz frequency band, high-throughput can be enabled on 802.11a or 802.11g radio profiles.

Select from the 802.11a radio profile drop-down menu.

Enter for the 802.11a radio profile name.

Select (check) the checkbox to enable high-throughput. By default, this is enabled (checked).

Click

Select the under the 802.11a radio profile.

Select from the drop-down menu.

Enter for the high-throughput radio profile name.

Configure the high-throughput radio settings (see Table 1 for details) and click .

Table 1: High-Throughput Radio Profile Configuration Parameters
Parameter	Description
40MHz intolerance	This parameter controls whether or not APs using this radio profile will advertise intolerance of 40 MHz operation. By default, this option is disabled, and 40 MHz operation is allowed. If you do not want to use 40 Mhz operation, select the 40MHz intolerance checkbox to enable this feature.
honor 40MHz intolerance	When enabled, the radio will stop using the 40 MHz channels if the 40 MHz intolerance indication is received from another AP or station. Uncheck the Honor 40 Mhz intolerance checkbox to disable this feature. Default: Enabled
CSD override	Most transmissions to high throughput (HT) stations are sent through multiple antennas using cyclic shift diversity (CSD). When you enable the CSD Override parameter, CSD is disabled and only one antenna transmits data, even if they are being sent to high-throughput stations. This enables interoperability for legacy or high-throughput stations that cannot decode 802.11n CDD data. This option is disabled by default, and should only be enabled under the supervision of Aruba technical support. Use this feature to turn off antenna diversity when the AP must support legacy clients such as Cisco 7921g VoIP phones, or older 802.11g clients (e.g. Intel Centrino clients). Note, however, that enabling this feature can reduce overall throughput rates.

Select the .

This radio profile represents activity on the 2.4 GHz frequency band. Since the high-throughput IEEE 802.11n standard operates on the 5 GHz and/or 2.4 GHz frequency band, high-throughput can be enabled on 802.11a or 802.11g radio profiles.

Select from the 802.11g radio profile drop-down menu.

Enter for the 802.11a radio profile name.

Select (check) the checkbox to enable high-throughput. By default, this is enabled (checked).

Click

Select the under the 802.11g radio profile.

Select from the drop-down menu.

Enter for the high-throughput radio profile name.

Configure the high-throughput radio settings (see Table 1 for details) and Click.

Select, under the Profiles list, to reveal the WLAN profiles.

Select the profile.

Select from the drop-down menu.

Enter for the virtual AP profile name.

Click .

Select from the drop-down menu associated with the “ht-vap-corpnet” virtual AP profile. The SSID Profile dialog box appears.

Enter for the SSID profile name.

Click to create the SSID profile and return to the virtual AP profile page.

Click on the virtual AP profile page.

10.

Select the virtual AP profile.

Select from the drop-down menu.

Click .

11.

Select the SSID profile . The High-throughput SSID profile option will appear below in the profiles list.

12.

Select the .

Selectfrom the drop-down menu.

Enter for the high-throughput SSID profile name.

Configure the high-throughput SSID profile settings (see Table 2 for details).

The High-Throughput SSID profile configuration settings are divided into two tabs, Basic and Advanced. The Basic tab displays only those configuration settings that often need to be adjusted to suit a specific network. The Advanced tab shows all configuration settings, including settings that do not need frequent adjustment or should be kept at their default values. If you change a setting on one tab then click and display the other tab without saving your configuration, that setting will revert to its previous value. Both basic and advanced settings are described in Table 54.

Click assign it to the SSID profile.

Table 2: High-Throughput SSID Profile Parameters
Parameter	Description
Basic High-Throughput SSID Profile Settings
High throughput enable (SSID)	Determines if this high-throughput SSID allows high-throughput (802.11n) stations to associate. Enabling high-throughput in an WLAN high-throughput SSID profile enables Wi-Fi Multimedia (WMM) base features for the associated SSID.
40 MHz channel usage	Enable or disable the use of 40 MHz channels. This parameter is enabled by default.
Very High throughput enable (SSID)	Enable/Disable support for Very High Throughput (802.11ac ) on the SSID.
80 MHz channel usage (VHT)	Enables or disables the use of 80 MHz channels on Very High Throughput (VHT) APs.
VHT - Explicit Transmit Beamforming	Enable or disable VHT Explicit Transmit Beamforming for the AP-220 Series. When this parameter is enabled, the AP requests information about the Multiple-Input and Multiple-Output (MIMO) channel and uses that information to transmit data over multiple transmit streams using a calculated steering matrix. The result is higher throughput due to improved signal at the beamforming (the receiving client). If this parameter is disabled, all other transmit beamforming settings will not take effect.
Advanced High-Throughput SSID Profile Settings
VHT - Supported MCS Map	Allows you to set the supported Modulation and Coding Scheme (MCS) map for spatial streams 1 through 3. Each drop down list corresponds to a spatial beginning with 1 on the left and ending with 3 on the right. Default values are set to 9 for each spatial stream.
VHT - Transmit Beamforming Sounding Interval	Time interval in seconds between channel information updates between the AP and the beamformee client. (AP-220 Series only)
BA AMSDU Enable	Enable/Disable Receive AMSDU in BA negotiation.
Legacy stations	Allow or disallow associations from legacy (non-HT) stations. By default, this parameter is enabled (legacy stations are allowed).
Low-density Parity Check	If enabled, the AP will advertise Low-density Parity Check (LDPC) support. LDPC improves data transmission over radio channels with high levels of background noise.
Maximum number of spatial streams usable for STBC reception	Controls the maximum number of spatial streams usable for STBC reception. 0 disables STBC reception, 1 uses STBC for MCS 0-7. Higher MCS values are not supported. (Supported on the AP‑90 series, AP‑130 Series, AP‑68, AP‑175 and AP‑105 only. The configured value will be adjusted based on AP capabilities.)
Maximum number of spatial streams usable for STBC transmission.	Controls the maximum number of spatial streams usable for STBC transmission. 0 disables STBC transmission, 1 uses STBC for MCS 0-7. Higher MCS values are not supported. (Supported on AP‑90 series, AP‑175, AP‑130 Series and AP‑105 only. The configured value will be adjusted based on AP capabilities.)
MPDU Aggregation	Enable or disable MAC protocol data unit (MPDU) aggregation. High-throughput APs are able to send aggregated MAC protocol data units (MDPUs), which allow an AP to receive a single block acknowledgment instead of multiple ACK signals. This option, which is enabled by default, reduces network traffic overhead by effectively eliminating the need to initiate a new transfer for every MPDU.
Max received A-MPDU size	Maximum size of a received aggregate MPDU, in bytes. Allowed values: 8191, 16383, 32767, 65535.
Max transmitted A-MPDU size	Maximum size of a transmitted aggregate MPDU, in bytes. Range: 1576–65535
Min MPDU start spacing	Minimum time between the start of adjacent MPDUs within an aggregate MPDU, in microseconds. Allowed values: 0 (No restriction on MDPU start spacing), .25 µsec, .5 µsec, 1 µsec, 2 µsec, 4 µsec.
Short guard interval in 20 MHz mode	Enable or disable use of short (400ns) guard interval in 20 MHz mode. This parameter is enabled by default. A guard interval is a period of time between transmissions that allows reflections from the previous data transmission to settle before an AP transmits data again. An AP identifies any signal content received inside this interval as unwanted inter-symbol interference, and rejects that data. The 802.11n standard specifies two guard intervals: 400ns (short) and 800ns (long). Enabling a short guard interval can decrease network overhead by reducing unnecessary idle time on each AP. Some outdoor deployments, may, however require a longer guard interval. If the short guard interval does not allow enough time for reflections to settle in your mesh deployment, inter-symbol interference values may increase and degrade throughput.
Short guard interval in 40 MHz mode	Enable or disable use of short (400ns) guard interval in 40 MHz mode. This parameter is enabled by default. A guard interval is a period of time between transmissions that allows reflections from the previous data transmission to settle before an AP transmits data again. An AP identifies any signal content received inside this interval as unwanted inter-symbol interference, and rejects that data. The 802.11n standard specifies two guard intervals: 400ns (short) and 800ns (long). Enabling a short guard interval can decrease network overhead by reducing unnecessary idle time on each AP. Some outdoor deployments, may, however require a longer guard interval. If the short guard interval does not allow enough time for reflections to settle in your mesh deployment, inter-symbol interference values may increase and degrade throughput.
Supported MCS set	A list of Modulation Coding Scheme (MCS) values or ranges of values to be supported on this SSID. The MCS you choose determines the channel width (20MHz vs. 40MHz) and the number of spatial streams used by the mesh node. The default value is 1–23; the complete set of supported values. To specify a smaller range of values, enter a hyphen between the lower and upper values. To specify a series of different values, separate each value with a comma. Examples: 2–10 1,3,6,9,12 Range: 0–23.
Temporal Diversity	When this feature is enabled and the client is not responding to 802.11 packets, the AP will launch two hardware retries; if the hardware retries are not successful then it attempts software retries. This setting is disabled by default.

In the CLI

(host)(config) #rf ht-radio-profile ht-radioa-corpnet

(host)(config) #rf ht-radio-profile ht-radiog-corpnet

(host)(config) #rf dot11a-radio-profile ht-corpnet-a

high-throughput-enable

ht-radio-profile ht-radioa-corpnet

(host)(config) #rf dot11g-radio-profile ht-corpnet-g

high-throughput-enable

ht-radio-profile ht-radiog-corpnet

(host)(config) #wlan ht-ssid-profile ht-ssid-corpnet

high-throughput-enable

(host)(config) #wlan ssid-profile ht-corpnet

ht-ssid-profile ht-ssid-corpnet

(host)(config) #wlan virtual-ap ht-vap-corpnet

allowed-bands all

ssid-profile ht-corpnet

(host)(config) #ap-group ht-corpnet-ap

dot11a-radio-profile ht-corpnet-a

dot11g-radio-profile ht-corpnet-g

virtual-ap ht-vap-corpnet

Managing High-Throughput Profiles

Use the following commands to create a high-throughput radio profile or edit an existing profile. For details, see Table 1.

(host)(config) #rf ht-radio-profile <profile>

40MHz-intolerance

clone <profile>

honor-40MHz-intolerance

disable-diversity-spreading

Use the following commands to create a high-throughput SSID profile or edit an existing profile. For details, see Table 2.

(host)(config) #wlan ht-ssid-profile <profile>

40MHz-enable

clone <profile>

high-throughput-enable

ldpc

legacy-stations

max-rx-a-mpdu-size {8191|16383|32767|65535}

max-tx-a-mpdu-size <bytes>

min-mpdu-start-spacing {0|.25|.5|1|2|4|8|16}

mpdu-agg

no...

short-guard-intvl-20MHz

short-guard-intvl-40MHz

STBC-rx-streams

STBC-tx-streams

supported-mcs-set <mcs-list>