With release 5.2.12, LANforge has support for 802.11 AC. It utilizes the Qualcom-Atheros (QCA) ath10k linux driver and modified firmware. The NIC supports 3x3 MIMO, up to 1.3Gbps encoding rades, and up to 32 virtual stations per NIC. 802.11a/b/g/n (ath9k) NICs can be mixed with ath10k NICs for increased station count.

The 802.11AC NIC, driver, and firmware is still a bit limited and is not as stable as the existing 802.11a/b/g/n ath9k solution. This page lists known bugs and limitations as well as some performance numbers and related information.

Throughput

As always with wifi, throughput depends on a great deal of things, so you may see better or worse performance in your own testing. When testing with LANforge AP (using ath10k chipset), we see maximum throughput of about 600Mbps upload and about 400Mbps TCP download. UDP upload may reach 700Mbps, and download 500Mbps. Over-the-air testing to a commercial AP shows about 500Mbps upload and download using TCP traffic. Other users have reported up to about 800Mbps download speed on un-specified APs. In order to support multiple stations connected to the same AP, rx encryption must be disabled in hardware, so download rates using WPA encryption are significantly slower than upload rates or non-encrypted download rates.

In addition, we have run some automated performance tests using LANforge stations against a LANforge AP. We can get higher throughput by running a tuned individual connection, but these give some idea of how the automated capacity test runs with 802.11AC:

WiFi Capacity Plugin: TCP throughput, 1-32 stations, download, open.	Summary Graph (366Mbps - 75Mbps)
WiFi Capacity Plugin: TCP throughput, 1-32 stations, download, wpa2.	Summary Graph (120Mbps, CPU-Bound)
WiFi Capacity Plugin: TCP throughput, 1-32 stations, upload, open.	Summary Graph (550Mbps - 270Mbps)
WiFi Capacity Plugin: TCP throughput, 1-32 stations, upload, wpa2.	Summary Graph (550Mbps - 250Mbps)
WiFi Capacity Plugin: UDP throughput, 1-32 stations, upload, open.	Summary Graph (550Mbps - 325Mbps)
WiFi Capacity Plugin: UDP throughput, 1-32 stations, upload, open.	Summary Graph (350Mbps)

Upgrade your LANforge to support 802.11AC

In order for LANforge to support 802.11AC, you need to be running the (currently beta) LANforge 5.2.12 release or higher. You must also have an Atheros qualcom 802.11AC NIC. Current suggested model is WLE900VX from Compex, but other NICs with the ACA9880 chipset should work as well.

If your LANforge has a slot available for a new NIC, just put the AC NIC in that slot and cable up the SMA <-> u.fl pigtail connectors to the outside of the case. If you have to replace an existing ath9k NIC, it may have the antenna connectors hot-glued to the NIC. In this case, it may be easiest to just replace the SMA pigtail connectors instead of trying to disconnect them from the NIC.

To install the latest LANforge software and firmware, connect your LANforge to the internet and run the following command as root user:

perl <(curl -s http://www.candelatech.com/lf_kinstall.txt) --do_all_ct --kver 3.14.0+ --lfver 5.2.12

As kernel versions change, the command above may change slightly, so check this page again before doing each update.

After the software has been installed, you should edit the /etc/udev/rules.d/70-phyname.rules file to make sure the entry for the new ath10k NIC has proper MAC address to match that NIC. MAC addresses in this file must be in lower-case.

After restarting LANforge, the ath10k driver config options file should be autocreated: /etc/modprobe.d/ath10k.conf You should verify that the contents have the line below, at least:

options ath10k_core nohwcrypt=1

Known bugs and limitations

• Stuck-in-scanning when resetting ports.
  If you are running lots of virtual stations, select all, and click 'reset', some stations may be stuck scanning and unable to detect the AP(s). To work around this, bring up the Modify window for a station that is not connected and scanning, click 'Display Scan', and then click Scan.

  You can also do a similar command on the linux command line:

       iw dev sta30 scan
       

• DHCP + WPA2 issues on some APs.
  When running against some off-the-shelf APs, LANforge has trouble acquiring DHCP leases when using encryption. Against some other APs, there are no problems at all. It is not clear which system(s) are to blame for this, but please contact support if you see similar problems. Work-around is to use fixed IP addresses.
• wiphy stats are not supported.
  Current driver does not support radio stats. Per-station stats are supported. Work-around is to sum up all station stats using right-click -> Calculations feature on Port-Mgr tab of LANforge GUI.
• LANforge AP only supports channel 36.
  Should be a simple fix, just need to figure out how to properly specify the hostapd config file for different channels. LANforge stations work fine on various channels. Work-around would be to hand craft a hostapd.conf file and tell LANforge to use that.
• Very slow or broken station-to-station traffic.
  This is seen with at least some off-the-shelf APs. Work-around is to just use upload or download tests instead of station-to-station testing.
• Out-of-order packets see in download tests.
  This may not be a real problem, as reordered packets can be caused by OS queueing behaviour and any well-designed protocol will already be able to deal with out-of-order packets.