Microsoft Teams Video call kills Internet-Box 3

[davy3c]

Hi,

I have a strange problem with my Internet-Box 3 and Microsoft Teams. I was wondering if anyone had see any thing similar. 

During a Microsoft Teams video call, when connected by Ethernet, my Internet-Box 3 will randomly stop working. The red light is on solid, and all other devices in my house loose their connection to the Internet. The only solution is to power cycle the Internet-Box. If I don't use video with Teams (i.e. voice only), I have no problem. I don't appear to have a problem with Teams video calls over WiFi at my house on the same computer. I don't have a problem with Teams calls on my iPad. And, if I use the same computer and same Ethernet adaptor in my office or with a UPC connection (which I had at my old house) I have no problems. 

My setup is:

Apple MacBook Pro 2017 <-> Kanex USB-C Ethernet Adaptor <-> Ethernet cable <-> Netgear GS308 switch <-> Swisscom Internet-Box 3

Swisscom have kindly replaced the Internet-Box but unfortunately the problem is still there. I am getting good support from Swisscom but wondered if anyone in the community had a solution?

Thanks

Davy

[LeylaG]

Hi @davy3c

The problem you describe seems very odd indeed.

I noticed that a trouble ticket is in progress in your file. I hope the technicians will find out the cause and offer a solution.

Let us know 

[SkyBeam]

This indeed sounds like an unusual and very uncommon but interesting problem.

Just a couple of ideas:

• Indeed I have experienced in the past some routers crashing and resetting upon the transmission of special packet types. However this is very very uncommon and even more unlikely to be caused by teams which is relying on default TCP/IP stack to transmit data.
• EMI mght be considered. Assuming your IB3 is somewhat close to your conferencing device it might actually happen that interferences caused by devices like USB-3 adapters or even internal devices might cause EMI (electromagnetic interferences) actually causing you to lose the network link. As you say your IB3 turns "solid red" which typically means it lost sync and did not reboot this might be a valid option to check.

Following the potential of an EMI issue I recommend checking the cables and try some increased physical distance. Espeically USB3 is known to cause high-frequency interferences. So your USB Ethernet adapter might be the actual cause. Perhaps it would also be worth teting a very simple Fast-Ethernet adapter but I am afraid with MAC you are out of options as you likely need a USB-C type connector. Using WiFi might be an option too. Then try to move your device and power supplies as far away from the IB3 as possible jut to test if the issue still persists.

Broken power supplies are often a cause for interferences, along with powerline and USB3.

If you find the issue resolved when moving away your laptop and power supply from the IB3, then try to identify the hardware causing it and isolate/replace it (power supplies might still work, but radiating EMI far beyond compliance levels and might need replacement). Also assure to use shielded cables (ethernet, USB) and not the cheapest USB3 extension cord you can find on aliexpress.

[davy3c]

Hi @SkyBeam 

Thank you for your comprehensive suggestions. Unfortunately, I don't believe the problem is down to EMI. My Mac in my attic office, and my IB3 is in my living room, 2 floors below. I am using the internal cat-6 wiring in my home to connect the two. Since my original post, I have invested in another USB-C ethernet adaptor from a different vendor (but of course it could be the same device inside), but exactly the same thing happens. 

I did some experimentation making Teams video calls over WiFi by moving my laptop to my living room, and it works perfectly. I then tried plugging my Mac directly into the router using Ethernet, and the crash happens again. 

My instinct is that that this IS a problem with a specific packet that is only generated over Ethernet, and only generated when Teams is in a video call.

With continued working from home, I needed to find a solution, so I bought another Swisscom WLAN-box, that I now have installed in my attic office to allow me to connect over WiFi. This works reliably, but is only a workaround. I am sure the problem still exists.

Davy

[SkyBeam]

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@davy3c wrote:

I did some experimentation making Teams video calls over WiFi by moving my laptop to my living room, and it works perfectly. I then tried plugging my Mac directly into the router using Ethernet, and the crash happens again. 

---

This indeed sounds pretty uncommon. In fact I don't believe your device is generating different types of Ethernet frames or data packets on Ethernet as the software stack is the same essentially. However the Ethernet card driver might be involved in some checksum calculation etc. So you might also try different drivers.

The part "plugging my Mac directly" is not fully clear. Does your Mac have an Ethernet port or not? If it has, why are you using a USB-C type Ethernet adapter then? If it doesn't I suspect you tried to hook up your mac via USB-C Ethernet Adapter and a short Cat5e+ Cable to the internet box and you could reproduce the issue.

If the latter one is the case then you still did not completely rule out a potential issue with your USB-C adapter. Even if replaced. As you said it might work with the same chip and/or driver. Also I would still not eliminate the possibility of an electronical interference. Perhaps not radio based but wire-based. Remember that if you hook up your Mac to your IB via cable you generate an electrical connection. If the power supply or a broken component is causing noise on the line it could actually cause the IB to lose sync.

Just as an example (might not be your actual problem):

• Potential defect on the camera module of the Mac (or PSU issue)
• Turning on the internal camera on the Mac might inject noise on the "ground" plane of the macbook
• Ground plane is connected to your Ethernet and potentially directly wired to the shield of the Ethernet cable
• So your "noisy" ground would be connected to the ground of your IB
• Noise might cause IB to lose line sync on DSL

Well, without knowing all the schematics and/or measure your equipment it's impossible to say if this is potenitally an issue.

You might try if the same thing happens also with a different Mac (not sure if you have the possibility to test) or with another Ethernet adapter (potentially cheap Fast-Ethernet USB-A type with USB-C adapter would do).

Another option would be to try a network isolator like this one.

I am not saying it's impossible that a certain data package could crash router services, but I think it's pretty unlikely.

As you already found out connecting a WLAN Box to the cable in your attic office and connecting your Mac to the WLAN does not cause issues. In this case you should see the same traffic pattern on the wire then and your IB is supposed to crash too if this would be the case.

Another thought: Did you try to connect your Mac to one of the Ethernet ports on the WLAN Box?

So your network topology would look as follows:

Mac -> USB-C -> Ethernet -> WLAN box -> Ethernet cable to your living room -> IB

Perhaps the WLAN box ethernet would filter some of the (potentially injected) noise and stop your IB from rebooting - or it might kill your WLAN box then 😉

As of your reply I just see that if you create a galvanic separation between your Mac and the physical network (by using WLAN) you eliminate the problem. So a network isolator or using the WLAN box in between might help if the WLAN box is less sensitive to such noise - but remember you might still have some broken equipment causing potential electrical problems.