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Re: 19991004: Latency issues at Creighton

On Wed, 6 Oct 1999, Unidata Support wrote:

> 
> ------- Forwarded Message
> 
> >cc: address@hidden
> >From: Bryan Rockwood <address@hidden>
> >Subject: Latency Issues
> >Organization: Creighton
> >Keywords: 199910042035.OAA02665 IDD latency
> 
> Greetings Unidata,
> 
>  ...  (stuff answered by Tom Y.
> 
> Second, and more importantly, we are having data reception problems.
> About the middle of the day (from 11A.M. to 3P.M.), I get mostly reclass
> messages in the log files for the satellite data.  Also, surface obs are
> noticably late in getting to the machine and some times incomplete.  This
> occurs on both the primary (chinook.unl.edu) and the secondary 
> (weather.admin.niu.edu).  Further analysis from a traceroute shows pings 
> on the order of 500ms during this time of day to both locations.  Now, I 
> would have figured this was due to our split T1 on campus, but found out 
> that about a month ago, they switched from one split T1 to two dedicated 
> T1 lines.  Secondly, both the NIDS data and the lightning data are
> on time.  I know they are smaller data sets, but pings on the 
> traceroutes are about 200 to 300 ms smaller.  Is there something I could
> do in this case?  Would seeking different servers help?  Or would it
> be best to start talks with our ISP (US West) first and go from there?

Bryan,

I would talk with the ISP first during the times of higher latencies. They
might be able to configure the routes correctly. On the down side it could
just be high congestion that's the problem.  Also, you could try to find
another server that has good reception during that time of the day.
Here's the topology URL, try not to pick sites that have many downstream
connections.  It's getting harder to configure the IDD, there just isn't
enough relay nodes available with the capacity to feed the downstream
nodes.

http://www.unidata.ucar.edu/projects/idd/status/idd/fosTopo.html


Robb...



> Any guidance would be appreciated.  Thanks.
> 
> Bryan R.
> 
> 
> 
> ------- End of Forwarded Message
> 

===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================