Re: 20010611: problem ingesting Unidata-Wisconsin images at UCR(cont.)

Jimmy Mejia Fernández wrote:
> 
> Hello Anne.
> 
>         Here there is something that is very weird, I am downloading AVN
> files by ftp without any problem but from Unidata I receive nothing, I do
> not know what can be, but tomorrow I will have a meeting with the ISP, the
> output of the mtr is this, as you can see is not so bad for not to get
> more than a file 2 MB size, is not razonable to get only ONE file with
> this speed if I can get all the files using ftp instead of the ldm.
> 
> 
> inti.efis.ucr.ac.cr                                    Thu Jul 19 19:21:02
> 2001
> Keys:  D - Display mode    R - Restart statistics    Q - Quit
>                                            Packets               Pings
> Hostname                                %Loss  Rcv  Snt  Last Best  Avg Worst
>  1. CI-efis-ci.efis.ucr.ac.cr              0%   53   53     1    1    7 191
>  2. SanPedro-R16-S2-2-T1.crnet.cr          0%   52   52    43   10   38 96
>  3. SanPedro-R11-S0-2M.crnet.cr            0%   52   52    40   19   47 126
>  4. 208.133.200.137                        0%   52   52    48   25   71 208
>  5. 500.Serial1-4.IG1.MIA4.ALTER.NET       0%   52   52   487  458  513 672
>  6. 129.at-5-0-0.XR2.ATL5.ALTER.NET        0%   52   52   501  455  512 643
>  7. 192.ATM7-0.BR1.ATL5.ALTER.NET          0%   52   52   535  473  514 585
>  8. 204.255.168.74                         0%   52   52   547  460  510 595
>  9. acr2.Denverden.cw.net                  0%   52   52   470  413  457 515
> 10. ucar.Denverden.cw.net                  0%   51   52   445  419  461 602
> 11. internetr-frgp.ucar.edu                0%   51   52   464  397  467 661
> 12. vbnsr-n243-104.ucar.edu                0%   51   52   485  402  465 612
> 13. mlra-n2.ucar.edu                       0%   51   52   471  420  456 628
> 14. motherlode.ucar.edu                    0%   51   52   461  395  464 585
> 
> Any way I will tell you what we can find here with the people of the ISP.
> 
> Jimmy

Hi Jimmy,

I hope your ISP is able to help.  Here are some facts to present to him
as I've gleaned them from our archives.

As of April 28, things seemed to be working for you.  Then, by June 11
you were no longer getting data.  That was the point at which we
determined that RPCs were being timed out.  I would ask the provider if
anything changed in that period of time.

Do you know how well ftp is working for you?  I understand that you're
getting files, but how long is it taking?  While we were visiting your
machine we downloaded the mtr program (and are now using it here -
thanks!), and the ftp worked but it was extremely slow.  It took 1 to 2
hours to download a 200K file.  As I watched the ftp  transfer rate it
continually dropped from several hundred bytes per second down to 35 the
last time I looked before I gave up watching.  

You might mention to the ISP that the LDM is RPC based.  It transfers
data in 16K chunks. I think that packet loss is the big problem now. 
Although your results above look good, when I ran mtr just now from here
to your site there was still significant packet loss.  I suspect you
happened to catch things at a good moment.  Can you get such good
results if you let it run for a while?

Good luck with your ISP.  Please let us know if you learn anything.

Anne
-- 
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Anne Wilson                     UCAR Unidata Program            
address@hidden                 P.O. Box 3000
                                  Boulder, CO  80307
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Unidata WWW server       http://www.unidata.ucar.edu/
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