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20040614: LDM related Question

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  • Subject: 20040614: LDM related Question
  • Date: Mon, 14 Jun 2004 07:15:41 -0600
>From: Tarun Banka <address@hidden>
>Organization: CSU
>Keywords: 200406140800.i5E807tK001480 LDM

Tarun,

>I am a graduate student working with Dr. Chandra at Colorado State University 
>on the LEAD Project. I have some questions realted to the LDM Protocol.
>
>Could you please tell me what's the maximum throughput possible using LDM 
>between two end machines.

We ran stress tests on the top level relay node we operate here at
UCAR, thelma.ucar.edu, in which it relayed a sustained 1.2 TB of data
per day to some 100 downstream connections (total volume, not volume
between two machines) without introduction of latency.  During this
test, the peak transfer rate was over 2.6 TB per day.  We routinely
feed all data available in the IDD from thelma to multiple machines at
Unidata and in the community, again without introduction of latency.

One of the machines getting pretty much all of the data in the IDD from
thelma is sunset.atmos.colostate.edu.

For reference, the IDD contains all NEXRAD level II data in addition to
the highest volume datastream CONDUIT.  Plots of data volumes being
received by machines participating in the IDD and reporting LDM-6
statistics can be seen at:

http://my.unidata.ucar.edu/content/software/idd/rtstats/siteindex.php

>As I understand, LDM uses TCP as a transport layer 
>protocol, does that impact the througput.

TCP is the transport layer for the Internet, so its use is inherent
in doing any access across the Internet.

>If my applications has minimum rate requirement for the radar data, then Is it
>possible to satisfy this request using LDM ?.

Easily.

>Looking forward to hear from you soon.
>
>Regards,
>Tarun

Cheers,

Tom Yoksas
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