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[LDM #JYJ-388203]: Question about Network Transport Layer protocol(s) for LDM

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  • Subject: [LDM #JYJ-388203]: Question about Network Transport Layer protocol(s) for LDM
  • Date: Thu, 25 Apr 2013 10:55:15 -0600
Steve,

> I'm working on a project that may use LDM for the exchange of weather
> data.  I have a few questions pertaining to the underlying network
> behaviors for systems using LDM for data exchange..
> 
> The fist question has to do with the Layer 4 protocol used by LDM: Does it
> use UDP and rely on an upper-layer protocol for data delivery integrity?

The LDM uses ONC RPC (both batched/asynchronous and unbatched/synchronous) over 
TCP. The higher level logic controls connection and disconnection recovery.

> An important factor in our application is datalink capacity and effective
> throughput.  Is the (client-server?) protocol exchange documented so we
> could estimate traffic load/needs?

Do you know about 
<http://www.unidata.ucar.edu/software/ldm/ldm-current/basics/index.html>?

The overhead is minimal (less than 10%), so the traffic rates are set by the 
data rates for the most part. Do you know about 
<http://www.unidata.ucar.edu/software/idd/rtstats/>?

> Does LDM use DSCP marking -- to enable us to implement Quality of Service
> (QoS)?

No.

If a proposal gets funded by the NSF, however, then I'll be working on a 
version of the LDM that uses multicast technology over virtual circuits. QOS 
would then be implicit.

> Any all information you could provide would be helpful.
> 
> Thank you,
> Steve Davidson
> CU Boulder grad (Physics PhD, 1987) -- I miss the flatirons!

They're 1/2 snow covered. Quite beautiful.

_______________________
> Dr. Steven A. Davidson
> Engineering Fellow
> Raytheon Certified Architect
> Raytheon Space and Airborne Systems
> 1001 Boston Post Road
> Marlborough, MA  01752-3789
> 508-490-3327 (office)
> 508-361-2827 (mobile)
> address@hidden

Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: JYJ-388203
Department: Support LDM
Priority: Normal
Status: Closed