Hello,

I would like to implement QoS for Microsoft Teams.

As per Microsoft's documentation, the following address ranges should be optimized for Teams: Docs are here:
https://docs.microsoft.com/en-us/micros ... re-network

And here:
https://docs.microsoft.com/en-us/micros ... ion-method

I did make some experiments and I kind of understand how to mark outbound traffic and prioritize that, but not how to do so for the inbound traffic (which may come from those ranges but also from different peers in peer-to-peer scenarios).

I would appreciate if someone with more experience with queue trees would explain how to properly set this up so that there is guaranteed 1Mbps up and 2Mbps down for Microsoft Teams.

Are you the ISP ? I don't see any real-world value on INBOUND QoS for such Internet application ?
For me, QoS is as much as possible an "end2end" story, not just on a single device.
You should at least be able to signal your upstream node to hold back some of the packets before they are placed on the link between yourself & ISP. (or put the Teams packets first on the links before other type of traffic)
When you have your own datacenters (with application servers), have some lines that accept & handle DSCP values and you control the routers on a certain premises you can do some end2end stuff.

Offcourse if you have something like Azure ExpressRoute links probably Teams is also accessible through there with QoS when properly engineered.

Are you the ISP ?

No. Just someone who wants to have undisturbed Teams experience with coworkers when working from home regardless of what other members of the household (or even myself) are doing on the internet. I have Mikrotik hardware good enough to solve that problem.

I don't see any real-world value on INBOUND QoS for such Internet application ?

To guarantee (reserve) download bandwidth when there is other heavy downloading on the connection.

For example if I have 500Mbps download speed, a browser can download a file at 500Mbps, but if Teams is used at the same time, it should get its own 2Mbps download rate, and browser should be capped at 498Mbps.

Rate-limiting / capping / traffic-shapen is often done on the EGRESS interface. So in your case the most easy perhaps to work with queues or something ?

https://wiki.mikrotik.com/wiki/Manual:Q ... Q_Examples

https://wiki.mikrotik.com/wiki/Bandwidt ... and_Queues

This should give you a good example & scenario's, some options exist. You could limit everything NOT related to the IP-prefixes of Teams that you mentioned.
If you do not have too much devices on your home-network that are real downloaders, children playing games etc this might do the trick to do it based on the IP the stations have on the LAN. (with PCQ)

I have the same issue. My ISP provides 250M/250M, which is sufficient for my needs. But, when working at home I use Teams a lot to communicate with my colleagues - and there are lots of disturbancies all the time... Is there a way to prioritize Teams traffic in the router to ensure good meeting quality?

Look here.

Specifically for your issue, the summary is that in download direction, it only makes sense to throttle traffic whose source can detect that it is throttled and can adjust to that (which is all TCP traffic and a few advanced applications using UDP as transport), but throttling download traffic whose source doesn't get any feedback about that has no effect. The throttling of download is actually made by queueing the packets in WAN->LAN direction.

So depending on what is the actual traffic which interferes with your videoconferencing sessions, you may or may not be able to make more space for the videoconferences in the download direction of the uplink or not.