The Metal is configured to connect to the 5GHz network and then distribute an IP via DHCP to the PC linked to it via Ethernet with a PoE injector.
This room is directly above the router broadcasting the 5GHz network and has the stock dipole omni antenna installed with the right angle N connector.
Under load, the link will average 150 to a maximum of 265Mbps UL or DL. CPU runs between 7% and 72%, temperature is nominal 34C - 38C.
Link power is nominal (between -61dBm and -54dBm) and I see no indication of DFS issues on the CPE side (there are detailed logs).
The wireless mode is set to station. There is no bridge (STP or RSTP) enabled. DHCP server for ether1 providing Ethernet client with IP address.
Default route for wlan1. Fasttrack enabled and from all tests, wired connectivity is sane. Here is the config for the wireless link and the security profile.
Code: Select all
name="wlan1" mtu=1500 l2mtu=1600 mac-address=REMOVED arp=enabled interface-type=Atheros AR9888 mode=station ssid="Devon" frequency=auto band=5ghz-n/ac channel-width=20/40/80mhz-Ceee secondary-frequency="" scan-list=default wireless-protocol=802.11 vlan-mode=no-tag vlan-id=1 wds-mode=disabled wds-default-bridge=none wds-ignore-ssid=no bridge-mode=enabled default-authentication=yes default-forwarding=yes default-ap-tx-limit=0 default-client-tx-limit=0 hide-ssid=no security-profile=Devon compression=no
name="Devon" mode=dynamic-keys authentication-types=wpa2-psk unicast-ciphers=aes-ccm group-ciphers=aes-ccm wpa-pre-shared-key="" wpa2-pre-shared-key="PassphraseRemoved" supplicant-identity="" eap-methods="" tls-mode=no-certificates tls-certificate=none mschapv2-username="" mschapv2-password="" disable-pmkid=yes static-algo-0=none static-key-0="" static-algo-1=none static-key-1="" static-algo-2=none static-key-2="" static-algo-3=none static-key-3="" static-transmit-key=key-0 static-sta-private-algo=none static-sta-private-key="" radius-mac-authentication=no radius-mac-accounting=no radius-eap-accounting=no interim-update=0s radius-mac-format=XX:XX:XX:XX:XX:XX radius-mac-mode=as-username radius-called-format=mac:ssid radius-mac-caching=disabled group-key-update=1h management-protection=disabled management-protection-key=""
Network connectivity and reachability when initially established works as configured, no firewall issues.
Under constant or random load of 10Mbps to 100 Mbps UL+DL, the wireless link will disconnect repeatedly and erratically. There is no predictable pattern to this.
The reasons are most commonly extensive data loss and less commonly no beacons received.
Reconnecting within 15-30 seconds, a bit longer because the DHCP client won't come straight back up once reassociated.
All other 5GHz clients are unaffected by this, it's just the Metal. The other wireless clients have no DHCP delay once connected and get addresses within 1s.
Additionally, other 5GHz devices connecting to the CPE with either 1x1, 2x2 or 3x3 have no trouble with traffic throughput in the 350Mbps to 650Mbps range without breaking a sweat.
The CPE has a 3x3 5GHz radio capable of 1300Mbps. The 5GHz radio config is a/n/ac, 3x3, Channel auto (Chooses 60@80MHz, DFS, region UK), Auto channel width (20/40/80MHz),
SGI support, STBC enabled, LDPC enabled, Frame bursting disabled.
The fibre link for the WAN side of the CPE is testing at 850+Mbps easily over Ethernet, so when I speed test the Metal at 250Mbps, I know it's getting less than theoretical throughput due to real world conditions (noise, attenuation, humidity, backscatter, reflections etc etc) but the constant disconnections are the deal breaker. Only the Metal exhibits this behaviour and it's driving me and the client insane. There is no indication of what it could be like CPU bottlenecking because it never even hits 100%. There isn't even a great distance to blame it on! Worse so, sometimes the speed tests don't even cause a dropout, making it seem like it's finally functioning as intended. Then with lower than 1Mbps either direction, the disconnections happen again! The CPE side has no error or issue other than losing visibility of the client and recording the reassociation 25-35s later. This is not seen for other 5GHz clients as I mentioned, some of which have uptimes of over 6 days on the 5GHz CPE network (iPhones, iPads, Laptops).
I have tried various settings, manual-txpower, regulatory-domain (UK), no_country_selected with both regulatory-domain and manual-txpower,
changing the operating mode to 5GHZ-only-AC, N/AC, A/N/AC, A/N, only-N, A, increasing the Group Rekey from 30m to 1h, changing installation from
indoor, outdoor and any, station roaming disabled (there's only one SSID for 5GHz on the CPE), manually setting the frequency to connect on,
I've even gone so far as to lock it to the currently broadcast frequency which is less than ideal because of DFS for the CPE side.
In every case, the disconnections still reoccur mid-load and bring the test to a halt.
All test periods were at least 15 minutes with 5 minutes constant load, 5 minutes random load and 5 minutes of doing nothing.
Constant load tests were done with StarTrinity CST and speed tests with Ookla Speedtest app for Windows.
Link tests were done with the Metal to a hAP AC2 over a 15cm Cat6a cable and btest server, 94-96% gigabit speeds with CPU between 13% and 28%.
The firewall function is enabled but with less than 10 rules total for input and forward chain, there is no indication that this is causing any issues.
What's making this worse is that I cannot determine any cause for the wireless link itself because there is nothing descriptive about the link loss. See below.
I have tried the extra wireless logging and there is just radar detection output, so no useful feedback was gleaned.
Should I keep shaking my fist at god or is this an indication of a faulty unit?
I know that the wireless line up from MikroTik doesn't tend to be super great but this...why this?
I'm starting to wonder if any of the other Metals I've deployed are performing poorly like this unit.
I'm very sad because the Metal is such a hardy, well built piece of kit so to see it struggle like this is just painful.