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RDP screen stops refreshing but input is captured.

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RDP screen stops refreshing but input is captured.

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fgwg

Hi guys.

I'm seeing an issue in RDM for macOS where connections to some machines located far away with a higher RTT (~300ms) are unusable. The session connects, I get about 5 seconds of use and then the display stops working. My input continues to get captured though as whatever I click or type will show when I disconnect and reconnect the session. It will happen repeatedly. Sometimes I get lucky and it will remain usable for a while before it eventually & inevitably does the same.

The problem doesn't appear to happen on machines that are closer. But it also doesn't happen if I use the Microsoft RD app for macOS. It appears to be specific to RDM/freeRDP when a higher RTT is in play.

I'd appreciate any suggestions on what settings I could look at to help this?

Thanks

All Comments (4)

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Maxim Buisson

Hi,

I will open a ticket for this issue.
Just to be sure, it only happens to to RDP sessions, correct ?
Has it always happened or did it start happening after an update ?

Best regards,


Maxim Buisson

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Richard Markiewicz

Hello

To add to what my colleague wrote, there are a couple of things you can check in the meantime.

  • In the "Experience" tab, make sure you have "Detect Network Automatically" and "Enable data compression" checked
  • In the "Advanced" tab, make sure you are using Codec Level 8
  • Disable any "Local Resources" that you aren't using (e.g. audio redirection, hard drives)


To set some expectations, you might be hitting a current limitation. The MS RDP client supports both TCP and UDP (lossy) transports, but FreeRDP (which is the basis for the embedded RDP in RDM - the Microsoft client cannot be embedded on this platform) does not support UDP. This is the kind of scenario that UDP is particularly good for. Here is the relevant GitHub issue: https://github.com/FreeRDP/FreeRDP/issues/4978.

Please, let me know if you have any questions

Kind regards,

Richard Markievicz

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fgwg

Hi both. Thanks for the replies.

To answer the questions:

  • Yes, I've only observed the issue with RDP sessions
  • All of the options mentioned above were in effect, however, I tried reducing the network quality to Satellite and that seems to have fixed the issue. I was able to narrow it down further to the option of "Desktop background", which seems to be the one that causes the session to freeze. I realised that the reason for "detect network automatically" perhaps not addressing this is because I'm tunnelling via an SSH host, and therefore the RDP endpoint address is actually localhost.


If there's an improvement that can be made for this, that's great, but otherwise I can use this as a workaround.

Thanks again

avatar
Richard Markiewicz

Hello

Thanks for the update.

Indeed, it seems likely that the "detect network automatically" might not function properly if you're traversing a tunnel.

I'm afraid there's not a specific improvement we can make on our side. This scenario will likely work better when FreeRDP supports UDP transport - it's an often requested feature but very technically challenging to implement and brings its own downsides as well.

Please don't hesitate if you have further questions or comments

Kind regards,

Richard Markievicz