I’ve recently stumbled across an issue that affects 1GiGe NICs based on
the 82574L Intel chip. The e1000e driver version 1.0.2 has an
issue with the RX FIFO that can cause packet loss, even under
relatively light load. This will cause unexpected under-run conditions
in Gnu Radio applications talking to GiGe radio hardware, such as
USRP2, N2XX. The offending driver appeared in Linux kernel
versions 2.6.31 through 2.6.35, but was later fixed. Ubuntu Maverick
(10.10) has a 2.6.35 kernel, so the offending e1000e driver
is in there, and Fedora 12 (2.6.31) and Fedora 14 (2.6.35) have the
same issue.
The best thing to do is likely to follow your Linux distributions
guidelines for building/installing a new kernel that is 2.6.36 or newer,
or
try a different 1GiGe card that isn’t based on the 82574L and the
e1000e driver.