Newsgroups: comp.parallel.pvm
From: Graham Edward Fagg <sssfagg@reading.ac.uk>
Subject: Re: PVM Broadcast Communications?
Organization: University of Reading, U.K.
Date: Thu, 2 Nov 1995 17:43:16 +0000
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Message-ID: <Pine.SOL.3.91.951102173015.15693E-100000@suma3.reading.ac.uk>

On 1 Nov 1995, Peter Welch wrote:
> Dear PVM folk,
> What is the underlying communication protocol used in pvm?  In particular, does
> it support a reliable broadcast protocol over the ethernet?  If I want to send
> the same message to multiple clients using pvm, will the message be broadcast
> to all clients or sent to each one individually?  

Currently all host to host comms are via daemons using UDP datagrams 
using a minimum spanning tree algorithm. If you request direct 
routing in you get TCP sockets. Unless you have multiple 
clients processes per host its effectively individual sends.

> Currently I am using TCP/IP for communications which is a point-to-point
> connection between a service and all clients.  When I add too many clients, the
> ethernet becomes clogged: I exceed the ethernet bandwith.  Could I solve this
> problem by using pvm?

Not yet! This may be solved one day in the future by the layering of 
different protocols below PVM.

> Thanks,
> Peter J. Welch 
                                                                   O__
Graham.                                                            ,>/
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