[LAD] Strange network problem ?

Hello all, Today I had a strange problem when using the WFS system here. The 'master' PC sends a multicast message every 1024 samples (21.333 ms) to all 'render' PCs. This has to arrive on time, and when it's late the renderers will mute their output and report the error in their status messages. Today I used some ssh -X logins from my laptop in the WFS room to the WFS master to run Ardour and some other apps for a demo. All this worked well all the time, as it has done before. I left everything running when going for lunch with our visitors, and when I returned restarted Ardour to listen again. I got a lots 'of 'message too late' errors from the rendering machines, and interrupted sound. Strange enough this seemed to be related to the _volume_ of the sounds... In other words to Ardour's level meters. Restarting Ardour in a new ssh login did not help, but running it directly on the WFS master solved the problem. So apparently the network traffic required to update Ardour's meters was causing the delays. And clearly the whole remote X session was slower than normal. CPU loads looked normal. Now all this should be peanuts for a Gbit network that has no other traffic at all, and it worked perfectly before. I just never left it running for such a long time. Anyone an idea as to what is happening here, and how it could be cured ? TIA, -- FA Laboratorio di Acustica ed Elettroacustica Parma, Italia Be quiet, Master Land; and you, Professor, will you be so good as to listen to me ?