SFT1200 2.4 GHz Repeater Disconnects

Technical Support for Routers
21

One of the reasons why we disconnect? How did channel 0 be read from the beacon here?

"lmac[1] vif working channel(36) is different from channel(0) of received beacon frame, notify that we are lost!"

LOG says ...

Sun Nov 3 10:19:57 2024 daemon.info lua: (...pkg-mips_siflower/gl-sdk4-repeater/usr/sbin/repeater:548) <3>CTRL-EVENT-CONNECTED - Connection to dc:2c:6e:ed:04:c4 completed [id=0 id_str=]
Sun Nov 3 10:19:57 2024 user.notice mwan3[20542]: Execute ifdown event on interface wwan (unknown)
Sun Nov 3 10:19:57 2024 user.info mwan3track[20068]: Detect ifdown event on interface wwan (wlan-sta0)
Sun Nov 3 10:19:57 2024 user.notice mwan3track[20068]: Interface wwan (wlan-sta0) is offline
Sun Nov 3 10:19:58 2024 daemon.notice wpa_supplicant[29476]: wlan-sta0: CTRL-EVENT-DISCONNECTED bssid=dc:2c:6e:ed:04:c4 reason=1 locally_generated=1
Sun Nov 3 10:19:58 2024 daemon.info lua: (...pkg-mips_siflower/gl-sdk4-repeater/usr/sbin/repeater:548) <3>CTRL-EVENT-DISCONNECTED bssid=dc:2c:6e:ed:04:c4 reason=1 locally_generated=1
Sun Nov 3 10:19:58 2024 kern.warn kernel: [317172.048909] lmac[1] vif working channel(36) is different from channel(0) of received beacon frame, notify that we are lost!
Sun Nov 3 10:19:58 2024 kern.warn kernel: [317172.060313] lmac[1] {CTXT-0} unlink from {VIF-1}: status=4 nb_vif=2

22

So does that mean that you get disconnections because the uplink router/modem disconnects the repeater?

23

Which of the 2 devices (uplink router or the repeater) is hard to find out.

  • GL.inet repeater claims that of beacon with the wrong (zero) channel is received, and says it has lost the connection.
    The uplink router (Mikrotik) says ..
    disconnected, ok, signal strength -57/
    attempts to associate/
    connected signal strength -57/
    reassociating/
    disconnected, ok, signal strength -57/

In Mikrotik language, "reassociating" means that the device associates while still associated.

This happens on all my Mikrotiks hAPac2, hAPax2, hAPac3, wAPac, hAP Lite .... no other client device shows any problems on those AP, only the GL.inet SFT1200.

Same problem with my friend. He is testing at our 30 AP large monitored Mikrotik campus installation. Performance on all connections is excellent, except the SFT1200.

So who is dropping the connection here ? I think it is the GL.inet, not the uplink router.
2.4 GHz is actually unusable, 5 GHz drops too frequently under load.

EDIT: It was exceptionally bad this evening. Friend at remote location, with SFT1200 connections that last only 1 or 2 sconds, even on 5GHz band, what used to be 5 minute sessions. Ideal to do some tweaking on the Mikrotiks, that I manage remotely. Guess what ... session was stable for 8hours ! No disconnects. OK this was on 5 GHz band, 2.4GHz is stable if the 802.11g only is forced there. No such thing on 5 GHz (n or n/ac makes no difference).

So tweaked a lot (RTS/CTS, AMSDU size, only 6Mbps basic rate, multicast helper), and the "multicast helper" set to "Full" made it 100% stable. Not only no-disconnects, but 100%CCQ and the dynamic interface rate goes up to the max possible : 400Mbps for 40MHz width/2 stream/short guard. All other tweaks turned off, it remains stable 100% with only the "multicast helper" set to full, on Mikrotik

In Mikrotik the multicast helper set to "default", as it is set by default actually means the helper is OFF or disabled !
Multicast helper on Full, converts multicasts in separate unicasts.
Don't know if this is done for beacons also.

Mikrotik - SFT1200 : there clearly is a multicast/broadcast problem. Wrong channel info as read from beacon, forces disconnects. But yes beacon/multicast does not do ACK-NACK or retransmits.

Have to test this helper workaround on the 2.4 GHz band, and compare it to the previous 802.11g workaround.

EDIT 2

Previous ... now this is on 4.3.21 .... and this supports DFS channels now, scanning, selecting, receiving and repeat/transmitting on channel 132 , with country BE (Europe/ETSI) . More changes than listed in the release notes. the previous workaround on 2.4GHz as "802.11g" does not help ... anymore ???Everything to be tested again ???

And we have new error types now:
Sat Nov 9 14:21:10 2024 kern.warn kernel: [ 9333.012255] lmac[1] Error, msdu index reach maximum limit, 31
Sat Nov 9 14:21:10 2024 kern.warn kernel: [ 9333.018094] lmac[1] Error, buffer is not uploaded to host buffer completely

24

Damned GL.inet SFT1200 device. It claims a lot of external IP addresses as pointing to its own uplink MAC address, even when used in WLAN connected repeater mode, set as router (aka as WISP mode). This feature does exist for the LAN ethernet interface, as "DROP-in gateway", but it's not activated here, and it is not for the WLAN uplink interface. My Hotspot (Mikrotik) dynamic mode is triggered to NAT some of the leaked SFT1200-LAN addresses (192.168.8.x) to it's Hotspot normal range (where the SFT WLAN address is part of, as it got is from that Mikrotik DHCP). It sees too many MAC/IP links in DHCP and denies access.

Only wireless is used in this setup, no ethernet cable attached.

25

Can someone help how I would lock the BSSID in luci? I am in a hotel right now and having the same issue. The SFT1200 seems to be jumping between multiple BSSIDs and is dropping connection every time. It is completely unusable.

I've tried to edit the sta interface, add a BSSID and save the connection, but it keeps changing through the BSSIDs...

The SFT1200 seems to be pretty bad device. Support is horrible and I have the feeling that even gl-inet does not really have it under control...as it seems to be based on one version of openwrt which was compiled once by the chip/board manufacturer...and that's about it.

26

Please check if your device supports BSSID locking, see Repeater - GL.iNet Router Docs 4

27

There is no advanced setting at all on the SFT1200...

28

Damn :frowning:
The SFT1200 is something close to EOL-feel-alike ...

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29

Ok, so I got curious and had a look if there was a new upgrade. But the interface didn't show any. I went to the product page and there was a firmware upgrade to version 4! Too bad the upgrade section does not show that.

I now had the option to lock the BSSID...but it unfortunately didn't solve the issue. I've now disabled the 2.4 GHz network of the router as the hotel wifi is 2.4 GHz. I also set the option to only use 20MHz Bandwidth. That improved the issue a little bit...but still not really stable...

30

Latest firmware a month ago, chipset has actual Openwrt support, it's in hibernation and hopefully Siflower comes through with the needed drivers.

31

What Mikrotik is the uplink?
Mikrotik have a proprietary WiFi called Nv2 and a predecessor called Nstreme.
The sft1200 only has access to proper non-proprietary WiFi.

If a Mikrotik uplink finds a Mikrotik downstream they will converse in their own proprietary communication over the WiFi connection.

32

Just for anyone that passes here and has the same problem.
I don't really get it to work. I don't know which hardware is used on the hotel side but all devices work except the sft1200. It drops connection all the time. The access points only provide a 2.4GHz network with a lot of APs (I can see about 4-6 all the time).

I have it a little bit stable (enough to receive messages and mails and very light surfing, no video) with the following settings:

  • Turn off 2.4GHz network
  • Try to connect once through the GLI interface (if that works)
  • Switch to legacy mode in the networks settings in luci
  • Select a distinct BSSID (only one works in my case which is not the one with the best signal! All the others, I could never connect to)

I was never able to add the network in luci. It always instantly disappears (a bug?).

I don't know if the OpenWRT version is just to old...but the SFT1200 does not seem to be a reliable device. It is not the first time I am having problems connecting to networks...but I am also tired to use my vacation to find workarounds for issues.

33

Yes, good remark, but GL.inet SFT1200 will not even see the nv2 or nstreme wifi signals. It's not 802.11 (CSMA/CA) , but it is TimeDomainMultiplex based access. A proprietary TDMA implementation for Mikrotik.

I'm very well aware of the Mikrotik wifi settings (I made 3000+ replies in the Mikrotik forum, on wifi performance and stability problems, with tuning suggestions and workarounds)

To answer your question, the SFT has uplink to hAP ac2 with ROS 6.49.13 , a very stable version. I also test with ROS 7.12 and the newer Wifi drivers on hAPac3 and hAP ax2.

For the WLAN drivers my current tuning for SFT stabel wifi connection is:

  • set Multicast Helper to FULL
  • configure data rates, reduce Basic rates A/G to 6 MBps only
  • VHT Supported MCS is twice MCS 0-9 , but the 3th is set to "none"
  • VHT Basic MCS, is set to "none" (!!!)
  • AMSDU Limit and Threshold are both set to 2300 (is default 8192)

Wifi driver cannot be finetuned like the WLAN driver.

By the way: with the newest release, the SFT1200 does respond to DFS channels as repeater, with country set to Belgium. It still may not select DFS channels on it's own, as it seems not to be able to do Radar Detect. (As repeater the uplink AP has already done that Radar Detect.)

This works on the 5 GHz connection. The 2.4GHz is still a total disaster, unless the AP limits to "legacy" (or G only) , and does not use "n". Only problem is SFT1200 in that area.

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34

Status so far

  • DFS use with 5 GHz can clearly be seen in the log now. (v4.3.21)
  • disconnects with OpenWRT are all over the OpenWRT forum, with many tests and replies
  • Most replies after tests state: it is a broadcast/multicast problem (not received packet), and if it is for the ARP packet then there are repeated disconnects
  • " ARP/broadcast issues for wireless clients" in forum and github. Only solved since version 23.03
  • Use a SSH session on the SFT1200 and issue "ip neigh" command. And you will see the STALE state of ARP entries for AP, gateway and DNS server.
  • We learned to avoid the 802.11b rates (1Mbps ...) because of the beacon overhead (30 beacon senders at 1Mbps will use 50% of all airtime), but maybe here we should enable them, as failed broadcast/multicast transmission might be the ultimate cause of the disconnects.
  • that MSDU error : larger than 31 , is also still there in the log
  • "disconnect reason=2" ... caused by stale ARP entry ?
  • and every time SFT1200 (re)connects to the uplink AP, it's MAC address with the WAN and LAN IP address appear both in that ARP table of the uplink AP (local IP address leaking?)

"ip neigh" ... used it here: GL-SFT1200:/proc/sys/net/ipv4/neigh/wlan-sta0#

LOG lines:
Mon Nov 25 20:57:57 2024 daemon.info lua: (...pkg-mips_siflower/gl-sdk4-repeater/usr/sbin/repeater:548) <3>WPA: Group rekeying completed with b8:69:f4:[edit] [GTK=CCMP]
Mon Nov 25 20:57:57 2024 kern.info kernel: [30245.505752] hb-fmac 17800000.wifi-hb wlan-sta0: Add key for vif(0), key index : 1
Mon Nov 25 22:08:20 2024 kern.warn kernel: [34468.551984] lmac[1] Error, msdu index reach maximum limit, 31
Mon Nov 25 22:08:20 2024 kern.warn kernel: [34468.557780] lmac[1] Error, buffer is not uploaded to host buffer completely
Mon Nov 25 22:08:20 2024 kern.warn kernel: [34468.564763] lmac[1] Error, msdu index reach maximum limit, 31
Mon Nov 25 22:08:20 2024 kern.warn kernel: [34468.570546] lmac[1] Error, buffer is not uploaded to host buffer completely

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35

Doing more tests ... want to fix this!

Ordered a competing cheap CUDY TR1200 ...

And compared performance ... horrible GL-SFT1200 only gets 10Mbps down, 6 Mbps up as best values in all my different attempts (2.4 and 5 GHz) , while the CUDY TR1200 connecting to the exact same Mikrotiks from the same spot, just gets the full ISP speed I have (50Mbps down, 10Mbps up) on all connections.

The SFT 1200 when doing OOKLA Speedtest has this in its LOG ...
"txq 216, try to reduce ps skbs to advoid ps station block ndevq"
Don't know what this means.

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36

skbs aka socket buffers:
http://oldvger.kernel.org/~davem/skb.html

So ps I'm going to guess is packet something.
If you get past the avoid, ndevq, network device queue?

So it's reporting a bottleneck at the wireless station due to packet socket buffers need to be reduced.

Don't tempt me on the TR1200, beautiful design ruined by a 16mb flash chip, 16mb isn't big enough these days.

37

Thanks for the link.

I eventually downgraded the Firmware to 3.216. They (GL.inet) eliminated some things from the firmware package (like hotspot, etc) to make 4.x fit. But still this seems to be too heavy/big for the poor SFT1200.

Performance now with firmware 3.216 is 50% of the Cudy TR1200. This is MUCH better than the 4.3.21 firmware on the SFT1200 OPAL.

1 Like
39

tests continue on one remote SFT1200 with 4.3.21 and one with 3.216.

  • Exploring all config files via SSH "cat". SSH "iw list" command is very interesting: all info on MSDU,A-MSDU, MPDU, A-MPDU is there
  • 4.3.21 fails after hours of up-time with 5 GHz for no apparent reason. (Is a remote idle site, but with 10 competing SSID around)
  • the 2.4GHz link on the LAN side of the SFT (SFT as AP), to another Mikrotik (as station) is stable as a rock

24 hours passed

  • when reconnecting happens SFT picks just another SSID in its known network list, so it did not come back to the operational SSID
  • SFT1200 as station does pick up the channel to set the wifi interface (or would not connect), but is wrong on the channel width. It sets 20MHz for the 5GHz band, and 40MHz for the 2.4 GHz band. Infrastructure setting there is just the opposite
  • Wrong channel width leading to that warning/error : "siwifi_calculate_legrate invalid legrate" or not?
  • At reconnect start time the SFT uses 192.168.8.1 LAN IP on it's WWAN connection. Then only later uses the DHCP assigned IP.
  • mwan3 has very strict values in the tests for interface up/down. (low # bad pings for down, versus 8 good pings for re-enable as up)
  • any glitch in the uplink connection or in internet will trigger the interface down, and start the long mwan3 recovery
  • (added the local gateway as test-IP, to reduce downs by internet glitches)
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40

@bruce any chance of 3.218 for the Opal?

41

Don't see 3.218 for Opal.
Tested 3.216, much (!) better than 4.3.21.
But returned to 4.3.21 because expected Zerotier to be in there. It's not.

Also started looking with the Android GL.inet APP.
Hmmm, had not seen the "Force 20MHz bandwidth for 2.4G(hz)" option explained, in the web interface. It"s there if you click.
Seems exactly what's needed.
Tested.
No help so far.
2.4GHz still disconnects rapidly.

The LOG says every time ...
"Sun Dec 1 13:28:43 2024 kern.warn kernel: [54211.328067] lmac[0] Error, msdu index reach maximum limit, 31
Sun Dec 1 13:28:43 2024 kern.warn kernel: [54211.333921] lmac[0] Error, buffer is not uploaded to host buffer completely
Sun Dec 1 13:28:48 2024 daemon.notice wpa_supplicant[12187]: wlan-sta0: CTRL-EVENT-DISCONNECTED bssid=b8:69:f4:95:6d:fc reason=2"

Question is, what is "msdu index" , the index of MSDU in A-MSDU?? . A-MSDU is rather small in the uplink MT router. Same numbers as in the SSH session with "iw list" command in the SFT1200.

Maybe it is the MPDU index in the A-MPDU. That's done in the driver or hardware, and not visible to the OS. Mikrotik has small MPDU (A-MSDU), so there could be many in a A-MPDU.

Will test with MPDU aggregation OFF in Mikrotik.

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