Hello LDM Users and IDD Participants,
Recently a few of our sites experienced data reception that was severely
throttled or stopped for no apparent reason. Symptoms were inconsistent
and somewhat sporadic and included:
extremely low throughput
latency problems
RPC time outs
"can't contact portmapper" messages
"no route to host" messages
ldmping failure, usually due to RPC time out
In some cases a subset of products got through, but in other cases
nothing got through.
It was finally determined that these sites had installed Packetshaper, a
product developed by Packeteer to analyze and "shape" traffic. It is
often used to limit traffic from low priority applications. Packetshaper
is a box that generally sits between a router and switch. Thus, there's
no way to tell whether it's running except to ask your network
administrator.
This note is let our community be aware of the possibility that
Packetshaper may be affecting the flow of data into or out of their
sites.
Also, we've been in contact with technical support at Packeteer in order
to help sites configure Packetshaper to allow IDD traffic to flow as
freely as possible. For more information please see
http://www.unidata.ucar.edu/packages/ldm/packetshaper/packetshaper.html.
Anne
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Anne Wilson UCAR Unidata Program
anne@xxxxxxxxxxxxxxxx P.O. Box 3000
Boulder, CO 80307
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Unidata WWW server http://www.unidata.ucar.edu/
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