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I am considering distributed radiofrequency signal acquisition and generation 
using
two Ettus Research X310 SDR platforms, fed with the 1 PPS and 10 MHz outputs 
from our
White Rabbit (WR) network. In addition to these signals, the control software 
(libuhd) running
on the computer collecting data from all SDR platforms needs to timestamp 
packets in order
to synchronize acquisitions. If I run a 1GbE network through a switch, all 
works fine, I can
collect synchronous data from the local and remote site. In real life I'd like 
to use the
WR network to transfer the data: I know my network configuration is good since 
I can ping
the USRPs. I have increased MTUs on the host Ethernet interfaces and the WRS 
(running 
firmware 5.0.1) to 9000 as advised by libuhd. 
In all cases the synchronization of the USRPs fail with error messages
UHD Error:
x300 fw communication failure #1
EnvironmentError: IOError: x300 fw poke32 - reply timed out
while the same configuration works when replacing the WR network with a 1GbE 
switch. Is there
some sort of excess latency introduced by the networking layer of WR that might 
be the cause
of the timeout ? Is there any configuration I can tune to try to solve the 
issue ? Or lower some
of the timeout limit on libuhd ?

Thanks, Jean-Michel

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