#OpenThread Border Router + ZBT-2 (Thread) - radio tx timeout

1 messages · Page 1 of 1 (latest)

hard bluff
#

Hello,

I have a new ZBT-2 antenna since yesterday, commissioned it in Thread mode.
I am having intermittent issues where battery powered devices (Like the new IKEA TIMMERFLOTTE TH) drops off the network.
I am attaching a snipped from the logs.
The USB Powered device (ALPSTUGA air quality monitor (12289) does not drop and updates extremely fast. (which I like).

The antenna is connected to the server via USB extension cable, and it lives in an USB-3 port. My server does not have any USB-2 ports.
The antenna is passed through HA-OS running in proxmox, as VM.
I have also tried restarting the addon with "Hardware flow control" turned off, but it felt even worse, so I turned it back on.

I am also attaching an extensive log history, for reference., and a picture of the physical positioning of the antenna in my environment.
Has anyone dealt with this before and solved it? Are there any tips I could try?

I hope the provided information is conclusive enough to get something started. I assume with confidence that the ZBT-2 device is not faulty..
PS: If further documentation is needed or I might have missed, I am happy to provide.

Edit: I cannot include a snippet of the logs due to the 2000 char limit of discord, but I have included the log file anyway.

OTBR Version: 2.15.3
OTBR config:

device: /dev/serial/by-id/usb-Nabu_Casa_ZBT-2_DCB4D90B91FC-if00
baudrate: "460800"
flow_control: true
otbr_log_level: notice
firewall: true
nat64: false
📎 core_openthread_border_router_2026-01-09T18-49-56.650Z.log zbt-2.jpg
feral stream
#

Are the radios in that router on? you have it quite close to it and it may be causing interference with the thread radio. although it looks like you've got your zigbee radio in the same place, and if that has been fine, its probably ok, athough what channels is your thread radio, and the zigbee radio in the background on?

cedar gull
astral whale
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the recommendation for the ZBT-2 is to have it 25cm away from other 2.4ghz radios (e.g. bluetooth, zigbee, wifi)

#

z-wave is on a different frequency band so it doesn't matter as much, i think?

cedar gull
#

I separated them a little more. They were basically already there. Left to right, Eero, ZBT-1 (OTBR), Bluetooth, ZBT-2 (Xigbee), and ZWA -2 (ZWave). 10 or more inches apart.

IMG_1216.jpg
hard bluff
#

I have stabilized the situation, so here is what I've managed to learn.

  1. Never connection a ZBT-2 to an USB3.0. Either go 2.0 or but a hub to convert from 3.0 to 2.0
  2. Never multi-home your home assistant server. Don't use multiple NICs. Otherise, weird errors start happening. The thread devices seem to communicate very often to the border routers and the packets seem to sometimes go through the wrong „holes”. This leads to mDNS storms.
  3. Don't use thread devices too close (20-30 cm) to computer ports of other electronic devices. Interferences seem to kill the battery powered thread devices. in my case, one of the IKEA ones.
  4. Don't put your battery powered behind mirrors. This was also a problem for me.

My network has been stable since I've considered these 4 points. Now I am in another 12-24h observation cycle.

astral whale
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I was very surprised that the USB cable included with the ZBT-2 appears to be a USB3.0 cable. Using a USB2.0-only cable would probably have reduced interference quite a bit :(

hard bluff
#

I haven't noticed. I am using the original cable from the box. I strongly assumed, if it is in the box, it is the original and the correct one to use, so I have't checked anything. I am still using it, i've ust bought the USB2 hub.
Thread is nice, but it's veeery picky.