[Info-vax] VMS process communication

[Dave Froble]

On 9/14/2022 1:34 PM, Simon Clubley wrote:
> On 2022-09-13, Dave Froble <davef at tsoft-inc.com> wrote:
>>
>> Not arguing any of that.  All I was implying was that both sides of a
>> communication must insure a successful communication, or, it never happened.
>>
>
> Not that simple (for performance reasons).
>
> Protocols such as TCP, ZMODEM, and Kermit (with sliding windows enabled)
> are all asynchronous protocols where the delivery of data to the end user
> program is decoupled from the sending of ACKs back to the transmitter.
>
> The receiver end user program can easily have received a good amount of
> data from the transmitter before the transmitter has received the ACKs
> from the receiver to confirm receipt of that data.
>
> You need something that guarantees the receiver end user program and
> the sender end user program are in sync at all times ? You can do that
> with a layer on top of the underlying protocol, but you will take a
> serious performace hit for doing so.
>
> Simon.
>

What type of hit might one experience if the customer billing is say $1000 and 
the last 2 zeros are chopped off the message?

Not that that is anything real.  You cannot convince me that if the 
communication was not verified, it is anything but "it never happened".

Accuracy is a great deal more important than performance.  Actually, accuracy 
isn't everything, it's the ONLY thing.

-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
DFE Ultralights, Inc.
170 Grimplin Road
Vanderbilt, PA  15486