I am seeing really abysmal performance on my new Mikrotik WAP ac (RBwAPG-5HacT2HnD-US) units. I was using Netspot to create heat maps with active scanning to compare to my previous network (Apple AirPort Extremes) in order to finalize placement and noticed really low transfer rates using iperf3. Transfer rates were right around 100megabit speeds, on deeper inspection the ethernet ports had negotiated to 100meg-FD (even though the switch shows 1Gbps-FD). I set the WAPac ether1 to 1Gbps and tested again, but the performance isn’t what I would expect of 802.11ac 80Mhz or 802.11n for that matter.
My iperf3 server is a rather powerful machine with Linux with a 3.10 kernel and an Intel I219-LM NIC and is easily capable of line rate. I have verified that if I plug my client into the Cat6 cable that services the WAPac that it can get 940megabits with iperf3 to the same iperf3 server, so I think I have ruled out cabling being an issue, the cabling is the same that was used for my AirPorts.
As a comparison, my AirPort Extremes under the same environment settings achieved peak of ~100Mbps on 802.11n and >500Mbps for 802.11ac actual download transfer rate, the highest I am seeing on my Miktrotik is 802.11n with only a single station registered is <20Mbps for 802.11n and ~200Mbps for 802.11ac. I never had only a single station registered on the AirPort Extremes during the testing. I also disabled the radios on the “other” AP to avoid conflicts but the results didn’t improve, where I had both of the AirPort Extremes configured for the same channels for both 802.11n (1) and 802.11ac (149).
When looking at my clients (Apple devices with Broadcom BCM43xx 1.0) I noticed that none of them were showing 802.11ac negotiated transmit rates, it appears that the channel selection being used for the extension channels may not be compatible on these devices. I can’t find anything that outlines the recommend configuration for the channel width selection options 20/40/80mhz-Ceee | 20/40/80mhz-eCee | 20/40/80mhz-eeCe | 20/40/80mhz-eeeC. I can’t find any references that refer to “e” and “C” for extension and control channels, and the RouterOS documentation doesn’t cover it beyond saying what the options are. I switched to using 20/40/80mhz-Ceee and the clients at least seems to negotiate a higher transfer rate but they don’t actually observe better speeds. The clients report:
Supported Channels: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 36, 40, 44, 48, 52, 56, 60, 64, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 144, 149, 153, 157, 161, 165
I have two of these units, one deployed on my 2nd floor and one in my basement. The frequency monitor for them:
[admin@UpstairsWAPac] /interface wireless> frequency-monitor
number: 0
FREQ USE NF
5180MHz 1.8% -105
5200MHz 0% -105
5220MHz 1.5% -105
5240MHz 0% -103
5745MHz 0% -101
5765MHz 0% -101
5785MHz 0.1% -101
5805MHz 0% -100
5825MHz 0% -100
[admin@BasementWAPac] /interface wireless> frequency-monitor
number: 0
FREQ USE NF
5180MHz 0% -106
5200MHz 0% -106
5220MHz 1.4% -106
5240MHz 0% -103
5745MHz 0% -105
5765MHz 0% -102
5785MHz 19.3% -103
5805MHz 0.1% -103
5825MHz 0% -103
Currently I am focusing on the UpstairsWAPac unit. The current radio configuration is:
set [ find default-name=wlan1 ] band=2ghz-b/g/n country="united states" disabled=no frequency=2437 frequency-mode=regulatory-domain max-station-count=100 mode=ap-bridge multicast-helper=full name="Bamboo Forest" security-profile="Bamboo Forest" \
ssid="Bamboo Forest" wireless-protocol=802.11 wmm-support=enabled wps-mode=disabled
add disabled=no keepalive-frames=disabled mac-address=E6:8D:8C:C2:47:33 master-interface="Bamboo Forest" mode=ap-bridge multicast-buffering=disabled name="Bamboo Guest" security-profile="Bamboo Guest" ssid="Bamboo Guest" vlan-id=1003 vlan-mode=\
use-tag wds-cost-range=0 wds-default-cost=0 wps-mode=disabled
add default-forwarding=no disabled=no keepalive-frames=disabled mac-address=E6:8D:8C:C2:47:34 master-interface="Bamboo Forest" mode=ap-bridge multicast-buffering=disabled multicast-helper=disabled name="Bamboo IoT" security-profile=IoT ssid=\
"Bamboo IoT" vlan-id=10 vlan-mode=use-tag wds-cost-range=0 wds-default-cost=0 wps-mode=disabled
add disabled=no keepalive-frames=disabled mac-address=E6:8D:8C:C2:47:35 master-interface="Bamboo Forest" mode=ap-bridge multicast-buffering=disabled name=bamboozled security-profile="Bamboo Forest" ssid=bamboozled vlan-id=10 vlan-mode=use-tag \
wds-cost-range=0 wds-default-cost=0 wps-mode=disabled
[admin@UpstairsWAPac] /interface wireless registration-table> print stats
0 interface=Bamboo 5GHz mac-address=AC:BC:32:A6:3E:67 ap=no wds=no bridge=no rx-rate="6.5Mbps-20MHz/1S" tx-rate="1053Mbps-80MHz/3S" packets=35584,192170 bytes=3396299,284269235 frames=6281,98638 frame-bytes=3742920,285930098 hw-frames=13794,101720
hw-frame-bytes=15610265,290097186 tx-frames-timed-out=0 uptime=5m59s last-activity=590ms signal-strength=-46dBm@6Mbps signal-to-noise=58dB signal-strength-ch0=-50dBm signal-strength-ch1=-48dBm signal-strength-ch2=-55dBm
strength-at-rates=-46dBm@6Mbps 590ms tx-ccq=84% p-throughput=807408 distance=1 last-ip=192.168.1.11 802.1x-port-enabled=yes authentication-type=wpa2-psk encryption=aes-ccm group-encryption=aes-ccm management-protection=no wmm-enabled=yes
tx-rate-set="OFDM:6-54 BW:1x-4x SGI:1x-4x HT:0-23 VHTMCS:SS1=0-9,SS2=0-9,SS3=0-9"
The station/client reports RSSI: -46dBm, Noise: -92dBm, Tx Rate: 1170Mbps, MCS Index: 9. The station is ~9’ line of site with no obstructions (other than myself and my chair) from the UpstairsWAPac.
The iperf3 -c output:
Connecting to host 192.168.1.5, port 5201
[ 4] local 192.168.1.11 port 58851 connected to 192.168.1.5 port 5201
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-1.00 sec 9.67 MBytes 81.0 Mbits/sec
[ 4] 1.00-2.00 sec 12.1 MBytes 101 Mbits/sec
[ 4] 2.00-3.00 sec 21.8 MBytes 183 Mbits/sec
[ 4] 3.00-4.00 sec 59.2 MBytes 496 Mbits/sec
[ 4] 4.00-5.00 sec 60.5 MBytes 508 Mbits/sec
[ 4] 5.00-6.00 sec 50.2 MBytes 419 Mbits/sec
[ 4] 6.00-7.00 sec 433 KBytes 3.56 Mbits/sec
[ 4] 7.00-8.00 sec 191 KBytes 1.57 Mbits/sec
[ 4] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec
[ 4] 9.00-10.00 sec 14.2 MBytes 119 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth
[ 4] 0.00-10.00 sec 228 MBytes 191 Mbits/sec sender
[ 4] 0.00-10.00 sec 228 MBytes 191 Mbits/sec receiver
Ping stats, client to iperf3 server:
50 packets transmitted, 50 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.886/4.315/34.362/6.582 ms
Ping status, iperf3 server to client:
50 packets transmitted, 50 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.855/62.374/214.639/53.542 ms
Is the RBwAPG-5HacT2HnD-US actually not capable of supporting 802.11ac speeds? As it seems the CPU utilization is quite high during those few >400Mbps bursts in the iperf3. The published performance test on the product page shows line rate, is that not done actually passing traffic through the radios bridged to the single ethernet port?
Would greatly appreciate any pointers on what to look for as the cause of this. As for channel selection any recommendations there or should I just use “auto”? Is Ceee going to be the most universally supported or is it more co-dependent upon the channel selected?
