[Info-vax] An alternative history of computing

[Arne Vajhøj]

On 7/25/2021 8:41 PM, Simon Clubley wrote:
> On 2021-07-24, Arne Vajhøj <arne at vajhoej.dk> wrote:
>> A protocol is open if it itself is documented.
>>
>> Other protocols on top of it can be open or closed without
>> impacting that.
>>
>> There are also closed protocols on top of TCP/IP - that
>> does not make TCP/IP closed.
> 
> Those lower levels exist to provide services to the higher application
> levels. There is an expected set of core functionality at application
> level in order for a protocol to be useful and you can't call something
> open if you can't implement that expected set of functionality using the
> public standards.

But you can implement whatever functionality you want.

It may just not be compatible with somebody elses
proprietary implementation.

Let us take TCP/IP and database access protocol. Let
us assume that Oracle's protocol is a closed while
PostgreSQL's protocol is open. Then you can implement
a PostgreSQL compatible database server or a PostgreSQL
client, but you can't do the same for Oracle.

And that means absolutely nothing for whether
TCP/IP is open or not.

Arne