[jira] [Created] (GUACAMOLE-2095) RDP audio intermittently not working because of missed audio protocol instruction

["Weston Thayer (Jira)" <ji...@apache.org>]

Weston Thayer created GUACAMOLE-2095:
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             Summary: RDP audio intermittently not working because of missed audio protocol instruction
                 Key: GUACAMOLE-2095
                 URL: https://issues.apache.org/jira/browse/GUACAMOLE-2095
             Project: Guacamole
          Issue Type: Bug
          Components: guacd
    Affects Versions: 1.6.0
            Reporter: Weston Thayer


After upgrading to 1.6.0, I am experiencing about 15% of RDP connections failing to play audio from the remote computer. My remote computers are all Windows 10 and Windows Server (2019 through 2025), Windows version doesn't appear to matter.

I've created a reproducible example at [https://github.com/WestonThayer/bug-guacamole-noaudio]

I am not able to reproduce on 1.5.5 or 1.5.4 (at least with N=100 attempts).

I am using the official Docker images, which I realize contain other dependency upgrades, so this may not be in Guacamole itself.

Inspecting suggests the root cause is that the web client never receives the [audio instruction|
https://guacamole.apache.org/doc/gug/protocol-reference.html#audio-instruction] over it's WebSocket with guacamole, so it doesn't reply confirming that a stream was created, and subsequent audio blobs aren't sent for playback.
 
I added some logging to guacd which showed that [raw_encoder_send_audio|https://github.com/apache/guacamole-server/blob/f3f5b9d76649ccc24f551cb166c81078f4b5e236/src/libguac/raw_encoder.c#L34] is being called, but it seems to be dropped before making it to guacamole's java.net.Socket.



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