If you experience bad unit performance like intermittent connectivity, please consider following the steps below.
If possible, make sure you're running on SonicOS 6.5 or later as it includes major fixes and improvements for Wireless - see release notes for SonicWall™ SonicOS 18.104.22.168
Please, also upgrade the firmware of the SonicPoints to the latest one.
To do so go to the diag.html page of your firewall (https://<ip-address of your firewall>/diag.html – example: http://192.168.168.168/diag.html), scroll down to the wireless section and click on “Update All SonicPoint’s Firmware”.
Try to connect the SPs directly to the SonicWall | If this resolves the issue, please check your switches.
If you have a WLAN bridge to your internal LAN, please unbridge it and set fixed IP addresses for WLAN users.
For Intermittent connectivity/throughput issues:
NOTE: To test this, make sure you're testing with a new device supporting the latest Wireless standards and standing close (but not too much) to the SonicPoint.
Run a full RF Survey to your network.
Try to test on 5GHz only and disable 2.4GHz (Radio 1) if possible. Are you facing the same issue? If not, the problem might be related to interference on 2.4GHz.
Perform an IDS Scan (SonicPoint > IDS: Scan All) and go to SonicPoint | RF Analysis to understand if there are any interferences. If yes, please set the channels accordingly for best wireless environment.
High noise environment might stop beacon packets to pass so you should decrease the Noise Sensitivity Level. To do so please go to the diag.html page of your firewall and scroll down to the Wireless Section and set the Noise Sensitivity Level to Extremely Low. Accept the configuration change at the top of the page.
Go to SonicPoint | SonicPoints and press the Configure button on the right hand side, next to the each of the impacted SonicPoints.
On the General tab, disable the RF Monitoring (it impacts the performance and it should be only used for debug purposes)
On the Radio settings tabs for both Radio 0 and Radio 1 disable Short Guard Interval and Aggregation (IOS devices are usually the most impacted when these settings are enabled).
The Beacon Interval value depends on the number of VAPs. For each VAP you add, you need to increase the Beacon Interval by 100 (i.e. 3 VAPs will result in Beacon Interval set to 300).
Reduce the Fragmentation and RTS Thresholds to 2304.
If using Radio 1 (2.4GHz), on the Advanced tab for Radio 1, set the Preamble Length to Short.
It is not supported to use the same SSID for different 802.11 radios, as clients with tri-band cards may experience disconnection issues – name them separately.
CAUTION: Make sure you're applying all the above changes to all the SPs in your network and not just to one. If possible, you might configure these settings on the Wireless Profile and then reboot with factory default all your SonicPoints.