Re: [Discuss-gnuradio] Gigabit Ethernet cards

[Manuel Fuhr]

On Fri, Jul 2, 2010 at 22:40, Marcus D. Leech <address@hidden> wrote:
> I suspect that my GiGE NIC may be dropping packets.  It's an
> RTL8168d-type chip, according to "dmesg".
>
> Are there known-to-be-good-with-GnuRadio NICs for PCI with low-profile
> brackets out there?  This is for
>  a 2U server platform.
I have the same problem that some packets from the USRP2 are getting dropped.

I tested this with a USRP2 with the latest UHD fpga image
(u2_rev3-udp-ise12-20100615.bin) and firmware (txrx_uhd_20100621.bin).
The host computers were running the latest uhd host code
(a34f930a79a0c626706a5f7532d8f692446d3c35). The first test machine is
a Phenom X4 with Windows XP and two cards (i tested both), a Realtek
onboard chipset (RTL8111/8168B PCI Express Gigabit Ethernet
controller) and an Intel PCI Card (82541GI Gigabit Ethernet
Controller). I even tested with a third card (Intel Dual-Port PCI
Express card) but it also had the same problems. Second test machine
is a Core2 Duo running Debian/squeeze and has a Broadcom BCM5787M PCI
Express onboard.

Test was made using "rx_timed_samples --rxrate 25000000 --nsamps
1000000" and "rx_timed_samples --rxrate 62500000 --nsamps 1000000" (on
Windows built as release target) but it often indicates dropped
packets (SX) on both platforms. Capturing with wireshark (or ulogd
with pcap target) and decoding the VRT packets afterwards (using some
python scripts) shows the same result. I tried using the benchmark_rx
example but it fails because even after sending
"STREAM_MODE_STOP_CONTINUOUS".

I also tried increasing the buffer sized but this didn't solve the problem.

Thanks in advance,
Manuel