Empathy List Archives

usrp-users@lists.ettus.com

Discussion and technical support related to USRP, UHD, RFNoC

Printing "SSSSSS" when using USRP N210 with MIMO Cable

ZHOU Yuxuan

Thu, Aug 12, 2021 7:58 AM

Hi All,

I am using 2 USRP N210 with a Ethernet cable and a MIMO cable. But when I used it, it randomly print "SSSSSS" and "ERROR in recv pirate loop: ValueError: bad vrt header or invalid packet length." (again, randomly). The result was that if I sent 1000 packets when the ERROR occurs, I will only received 300 or less packets, sometimes less than 10.

I have searched for the answer to that but it said it may caused by NAT. However I just directly connect it using my Win10 system and Gnuradio 3.7.

Do you guys have any experience about that?

Regards,
Kevin

Hi All, I am using 2 USRP N210 with a Ethernet cable and a MIMO cable. But when I used it, it randomly print "SSSSSS" and "ERROR in recv pirate loop: ValueError: bad vrt header or invalid packet length." (again, randomly). The result was that if I sent 1000 packets when the ERROR occurs, I will only received 300 or less packets, sometimes less than 10. I have searched for the answer to that but it said it may caused by NAT. However I just directly connect it using my Win10 system and Gnuradio 3.7. Do you guys have any experience about that? Regards, Kevin

Marcus D. Leech

Thu, Aug 12, 2021 12:40 PM

On 08/12/2021 03:58 AM, ZHOU Yuxuan wrote:

Hi All,

I am using 2 USRP N210 with a Ethernet cable and a MIMO cable. But
when I used it, it randomly print “SSSSSS” and “ERROR in recv pirate
loop: ValueError: bad vrt header or invalid packet length.” (again,
randomly). The result was that if I sent 1000 packets when the ERROR
occurs, I will only received 300 or less packets, sometimes less than 10.

I have searched for the answer to that but it said it may caused by
NAT. However I just directly connect it using my Win10 system and
Gnuradio 3.7.

Do you guys have any experience about that?

Regards,

Kevin

'S' is sequence error, which means packets are getting dropped by your
network interface. We'll need more details about your configuration.

What sample rates?
Are both N210 connected via the same network adaptor?

What type of network adapter do you have? Some with 82579LM chips in
them randomly drop packets even when they aren't under
load.

On 08/12/2021 03:58 AM, ZHOU Yuxuan wrote: > > Hi All, > > I am using 2 USRP N210 with a Ethernet cable and a MIMO cable. But > when I used it, it randomly print “SSSSSS” and “ERROR in recv pirate > loop: ValueError: bad vrt header or invalid packet length.” (again, > randomly). The result was that if I sent 1000 packets when the ERROR > occurs, I will only received 300 or less packets, sometimes less than 10. > > I have searched for the answer to that but it said it may caused by > NAT. However I just directly connect it using my Win10 system and > Gnuradio 3.7. > > Do you guys have any experience about that? > > Regards, > > Kevin > > > 'S' is sequence error, which means packets are getting dropped by your network interface. We'll need more details about your configuration. What sample rates? Are both N210 connected via the same network adaptor? What type of network adapter do you have? Some with 82579LM chips in them randomly drop packets even when they aren't under load.