Re: [Discuss-gnuradio] uhd_fft and rx_ascii_art_dft die after 30 seconds

[Clark Pope]

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> Date: Sun, 30 Oct 2011 23:36:25 -0400
> From: address@hidden
> To: address@hidden
> Subject: Re: [Discuss-gnuradio] uhd_fft and rx_ascii_art_dft die after 30 
> seconds
>
> On 30/10/11 11:27 PM, Clark Pope wrote:
> >
> > I am running ubuntu 10.04 in vmware and connecting to an n210 via a gigabit 
> > ethernet USB dongle. When I run either uhd_fft.py or rx_ascii_art_dft all 
> > works fine for exactly 30 seconds and then the data display stops updating. 
> > If I rerun the app it works again for 30 seconds and stops.
> >
> > In wireshark the data looks good coming from 192.168.10.2 to port 49156 
> > until it hangs then pc sends packet on 35433 and usrp reponds on 49152 and 
> > it just goes back and forth forever.
> >
> > there's plenty of disk space and memory and no messages in dmesg. doesn't 
> > seem to matter what sample rate I choose. I assume it has something to do 
> > with vmware but just guessing. Any ideas? Thanks
> > _______________________________________________
> >
> >
> I would suspect some combination of VMWare and your USB Ethernet
> dongle. USB-2.0 operates at
> 480Msps *maximum*, which is just shy of *half* of the required Gigabit
> rates supported by
> *real* Gigabit ethernet cards.
>
>
> --
> Principal Investigator
> Shirleys Bay Radio Astronomy Consortium
> http://www.sbrac.org

Some more information on this. I've figured out that after the 30 seconds the 
VM network stack (I guess) throws an ICMP destination port unreachable packet 
which looking at the usrp firmware will kill the stream. There's no reason for 
the ICMP message since hundreds of packets to port 4140 precede the message. 
 
I guess its a long shot but maybe someone out there has seen this with ubuntu 
10.04 in vmware? Thanks