On Windows XP, I have tried connecting from the road to my home MythTV box via SSH using:
ssh -l mythtv -i [key file path] [hostname] -L 6543:10.1.1.203:6543 -f -N
I use the IP address for the mythtv box because I have other frontends on the network there.
Attached is my config.xml and log file.
MythtvPlayer connects, reads channel and recording info (that takes a while). I select a recording, click play. It starts playing fine, but as soon as I try to jump to the middle, or otherwise skip forward, it hangs. The files are transcoded, if that matters. Bandwidth isn't an issue, as far as I know.
I thought I had trouble with the backend at first, but I think that was user error.
config.xml
log.txt
From my point of view, if the SSH tunnel is established and you can even start the recording, the skipping/fast forward should not break the connection, nor should it require an additional port. But we have to look into that. Have you tried to finish a playback? Is it possible to start another one if the first one is a) finished or b) interrupted by skipping? this would allow us to understand if the backend connection is still alive or not.
Is it possible to up the debug on the player and also include a debug from the backend with -v network enabled?