Firstly I hate! Hate! Hate! PC’s this one crashed just as I was about to
send the first draft of this message.

Apologies for the length but it might help ‘others who follow in my
footsteps’.

Many many thanks to Lars et al for pointing me at sockets. I had visited
this area in the past but I didn’t make much sense then, not that it does
now. Anyway I thought I would try to understand IPC/sockets generally
before moving onto HTTP on port 80.

Using Lars examples I have got a cobol server and a cobol client program
running on my HP. Once an ipcconnect has been made the client loops (via a
counter) in ipcsend  n times sending data to the server. The server
receives data until it encounters a shutdown status (64), in which case it
returns to ipcrecvn or LOGOFF text at which point it closes. This works
fine.

I found that if I run the client program at two terminals at the same time,
the second client is locked out until the first client closes.

OK I thought, I would change the client loop so it restarted every time.
However when I tried this and only running a single client it appears to
hang after some 61 (ipcdest, connect, recv, shutdown, send, shutdown) loops
and then timesout. An immediate run of the client after results in an error
code 4 (Network error: Transport not initialised).

Can/should two (in this case identical) client processes be able to post to
the same socket at the same time?
Is the hang/network error a simple case of flooding the network with my
looping program?

TIA