[srsran-users] Performance issues

Wed Oct 4 12:52:20 UTC 2023

Hello, 

Just realised I have not CC’d srsran-users in my last reply to Ismael. The files are attached here although I am not sure what is the best way to share logs and other files with the members.

@Ismael, one further development since yesterday - The following warnings from UHD disappeared after I upgraded my USRP x300 FPGA images: 

[WARNING] [X300] For the 192.168.40.2 connection, UHD recommends a send frame size of at least 8000 for best
performance, but your configuration will only allow 2664.This may negatively impact your maximum achievable sample rate.
Check the MTU on the interface and/or the send_frame_size argument.
[WARNING] [X300] For the 192.168.40.2 connection, UHD recommends a receive frame size of at least 8000 for best
performance, but your configuration will only allow 2664.This may negatively impact your maximum achievable sample rate.
Check the MTU on the interface and/or the recv_frame_size argument.

HOWEVER the behaviour remained the same afterwards - that is, the throughput and instability issues continue even with send/receive frames sizes being 8000.

Kind Regards,
.Nemo

> On 3 Oct 2023, at 15:29, muhasard77 at gmail.com wrote:
> 
> Hi Ismael,
> 
> Thanks for your prompt response.
> 
> Please find attached the requested files.
> 
> There are some warnings generated by the UHD driver that I was already trying to figure out without success so far. 
> But, like you said if there is any other parameter tuning that I have got wrong, please highlight that too.
> 
> I was running an iperf3 test from the same machine that was running the SDR code using the command shown below. You will see that the traffic reported by iperf3 vs SDR UE trace also do not match.
> 
> You mentioned 100MHz SISO or 50MHz MIMO should not have much problem. Does that mean for SISO case, srslte can support 5 carrier components of 20MHz each and hence the maximum throughput that can be supported without any accelerators is 250Mbps?
> 
> Thank you very much for your support!
> 
> Kind Regards,
> .Nemo
> 
> 
> $ iperf3 -c 10.79.4.20 -R -l 1400 -u -b 50m -t 100 -p 5201
> Connecting to host 10.79.4.20, port 5201
> Reverse mode, remote host 10.79.4.20 is sending
> [  4] local 10.79.4.34 port 51679 connected to 10.79.4.20 port 5201
> [ ID] Interval           Transfer     Bandwidth       Jitter    Lost/Total Datagrams
> [  4]   0.00-1.00   sec  4.78 MBytes  40.1 Mbits/sec  0.294 ms  0/3583 (0%)  
> [  4]   1.00-2.00   sec  8.69 MBytes  72.9 Mbits/sec  0.200 ms  0/6508 (0%)  
> [  4]   2.00-3.00   sec  3.95 MBytes  33.1 Mbits/sec  0.364 ms  0/2955 (0%)  
> [  4]   3.00-4.00   sec  1.71 MBytes  14.3 Mbits/sec  0.462 ms  0/1279 (0%)  
> [  4]   4.00-5.00   sec  2.01 MBytes  16.9 Mbits/sec  0.456 ms  0/1506 (0%)  
> [  4]   5.00-6.00   sec  7.07 MBytes  59.3 Mbits/sec  0.218 ms  0/5296 (0%)  
> [  4]   6.00-7.00   sec  7.62 MBytes  63.9 Mbits/sec  0.855 ms  0/5709 (0%)  
> [  4]   7.00-8.00   sec  6.39 MBytes  53.6 Mbits/sec  0.205 ms  0/4786 (0%)  
> [  4]   8.00-9.00   sec  0.00 Bytes  0.00 bits/sec  0.205 ms  0/0 (0%)  
> [  4]   9.00-10.00  sec  0.00 Bytes  0.00 bits/sec  0.205 ms  0/0 (0%)  
> [  4]  10.00-11.00  sec  0.00 Bytes  0.00 bits/sec  0.205 ms  0/0 (0%)  
> [  4]  11.00-12.00  sec  0.00 Bytes  0.00 bits/sec  0.205 ms  0/0 (0%)  
> [  4]  12.00-13.00  sec  4.73 MBytes  39.7 Mbits/sec  1.074 ms  0/3544 (0%)  
> [  4]  13.00-14.00  sec  9.69 MBytes  81.2 Mbits/sec  0.490 ms  0/7254 (0%)  
> [  4]  14.00-15.00  sec  8.07 MBytes  67.7 Mbits/sec  0.344 ms  0/6048 (0%)  
> [  4]  15.00-16.00  sec  9.37 MBytes  78.6 Mbits/sec  0.244 ms  0/7015 (0%)  
> [  4]  16.00-17.00  sec  2.75 MBytes  23.0 Mbits/sec  0.277 ms  0/2056 (0%)  
> [  4]  17.00-18.00  sec  2.75 MBytes  23.1 Mbits/sec  0.419 ms  0/2060 (0%)  
> [  4]  18.00-19.00  sec  2.69 MBytes  22.5 Mbits/sec  0.696 ms  0/2012 (0%)  
> [  4]  19.00-20.00  sec  2.35 MBytes  19.7 Mbits/sec  0.238 ms  0/1760 (0%)  
> [  4]  20.00-21.00  sec  2.53 MBytes  21.2 Mbits/sec  1.330 ms  0/1894 (0%)  
> [  4]  21.00-22.00  sec  2.07 MBytes  17.4 Mbits/sec  1.786 ms  0/1553 (0%)  
> [  4]  22.00-23.00  sec  2.50 MBytes  20.9 Mbits/sec  1.223 ms  0/1869 (0%)  
> 

> 
>> On 3 Oct 2023, at 13:42, Ismael Gomez <ismael.gomez at srs.io> wrote:
>> 
>> Hi Nemo,
>> 
>> On Tue, 3 Oct 2023 at 10:54, <08.chancy_fantasy at icloud.com <mailto:08.chancy_fantasy at icloud.com>> wrote:
>>> Hello,
>>> 
>>> I am relatively new to srslte (but not to radios and SDRs..)
>>> 
>>> Already spent a couple of hours browsing / experimenting with the code and I must say it is very clean and well-written code. 
>>> However, it seems that performance remains the number 1 limitation. Ramping up to 75 PRBs on a Xeon 2.8GHz 8-core CPU, I notice a high degree of instability running an iperf3 UDP DL maximum throughput test. Of course, the throughput degrades sharply as the instability kicks-in (usually triggered by an innocent looking couple of underrun packets or an RLF). Note that these tests were run under controlled radio conditions with a commercial-grade eNB / ePC.
>>> 
>>> So, my first question is: can someone confirm the performance that I am seeing? Or is it just down to my not-so-capable platform? Is there a reference platform that can hit or approach maximum performance for say, 75 PRBs (100Mbps DL / 30 Mbps UL)?
>> 
>> We probably need to tune a few parameters there. Can you share your config files, console trace and log in warning please? 
>>  
>>> 
>>> Secondly, is it possible to off-load some of the heavy-lifting (turbo decoding e.g.) to an external device? We have an FPGA based platform that connects to the host via a PCI interface. Ignoring the development effort, my concern here is whether the cost of such off-loading (over much slower PCI bus and back) could already surpass the ~2ms processing window available..
>> 
>> We provide support for the bbdev interface to use the Intel ACC100 accelerator. But for those BW it's really not needed. Your Xeon 8-core should be able to do 100 MHz SISO or 50 MHz MIMO without major problems (assuming everything is optimally tuned) 
>>  
>>> 
>>> I have already combed through mailing list archives but could not find a straight answer to the above questions.
>>> 
>>> Kind Regards,
>>> .Nemo
>>> _______________________________________________
>>> srsran-users mailing list
>>> srsran-users at lists.srsran.com <mailto:srsran-users at lists.srsran.com>
>>> https://lists.srsran.com/mailman/listinfo/srsran-users
> 

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