[linux-audio-dev] jack.udp issues

jack.udp for me means many underrun in this configuration: x86 pc jackd -d alsa -d hw:0 jack.udp recv ^ | (FastEthernet network (100mbps)) | | powerpc pc jackd -d dummy jack.udp -r IP send the first thing that came in my mind was some network troubles like mtu.. further investigation (like involving two x86 hosts, or working directly without the switch, working with 802.11b networks...) made me think that jack.udp uses the audiocard driver for some kind of timing. now, i've some troubles running an audiocard with jack in the powerpc (my main computer) there is a way to make this system usable with dummy driver? i've noticed that this dummy driver has a "delay in microsecs" parameter, now i think if i can calculate the right number the problem will fade away, but i dont know how to do the math :( some one has an idea on this? or has solved a similar trouble? another question out of this trouble: someone knows how to raise the IRQ priority of the USB controller to an usable value? possibly not involving the use of the realtime patch, inusable on ppc-powermac, thanks for attention and eventual replies, and keep the good work on this audio software :) willy