The PTOP (Program-to-Program communication) service
is available on DS/3000 and NS 3000/V. It is a master-slave
protocol wherein a master process creates a slave process on a remote
node, the master sends data-exchange requests to the slave, and
the slave accepts or rejects the master requests.
The NetIPC (Network InterProcess Communication) and RPM (Remote Process
Management) services are available on NS 3000/V and NS 3000/XL.
These services provide a more flexible alternative to PTOP for developing
distributed applications. Since PTOP is not supported on NS 3000/XL,
any PTOP application to be migrated to an MPE XL system must be
rewritten to use NetIPC and RPM. These guidelines provide steps
for the conversion.
A distributed application using PTOP or NetIPC/RPM can be
divided into three phases:
Creation of the remote (slave) process
and the establishment of a communications channel between the local
(master) and the remote (slave) processes.
Data exchange over the communications channel.
Process termination and the shut down of the communications channel.
The rest of this appendix is divided according to creating
processes, exchanging data, and terminating processes. The sections
are then subdivided according to what you have to do on a master
program and on a slave program.
