Introduction

One of the major hurdles to overcome in making different MPI implementations interoperate is launching MPI applications in a multiple-vendor environment. Because we can't encompass all working environments, we must make some basic assumptions about those environments for which interoperability might most reasonably be expected.

ASSUMPTIONS:

 

1.

TCP/IP is available and in use on at least one computer within each implementation universe.

Rationale.TCP/IP need not necessarily be available on all computers which are to run MPI processes; we merely require that such machines be able to communicate with such a machine running under the local MPI implementation. (End of rationale.)

Discussion.One obvious alternative would be to use UDP instead. It has been decided that, in the absence of a specific counter-proposal, it would be much simpler to build on top of TCP. But anyone wishing to propose a complete windowing/error-recovery protocol based on UDP is warmly encouraged to do so! (End of discussion.)

2.

The use of rsh must not be assumed. However, all else being equal, those solutions which lend themselves nicely to rsh environments are preferable to those which do not.

3.

The use of UNIX must not be assumed. However, all else being equal, those solutions which lend themselves nicely to UNIX environments are preferable to those which do not.

CONCLUSION:

 

1.

host:port is the best convention to use for establishing initial connections between implementations