[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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



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


NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.