On 07/26/21 02:16, Arne Vajhøj wrote:
> On 7/25/2021 9:05 PM, Simon Clubley wrote:
>> On 2021-07-25, Arne Vajhøj <***@vajhoej.dk> wrote:
>>> On 7/25/2021 8:41 PM, Simon Clubley wrote:
>>>>
>>>> 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.
>>
>> But they are not considered to be part of the core TCP/IP stack.
>>
>> Everything that ships as part of a TCP/IP stack (including SSH,
>> Telnet, FTP, SMTP, etc) has a public specification that goes
>> with it.
>>
>> However, not everything that ships as part of the DECnet stack
>> on VMS has a public specification that goes with it.
>>
>> (And don't forget in addition that the public CTERM specification
>> is missing the VMS specific bits.)
>
> Telnet, SSH, FTP, SMTP etc. are individual specifications - they
> are not part of the specs for TCP and IP.
>
> And they do not always come with TCP/IP.
>
> They often do, because the specs are open and open source
> implementations exist making them easy to deliver.
>
> But being frequently bundled with does not make them
> part of a protocol.
>
> Arne
TCP/IP is is just one layer of a stack of networking
parts that are designed to work together, a very
elegant and well engineered design. TCP, along with UDP,
are layered above IP, ICMP and IGMP, which in turn are
layered above the data link layer and hardware at
lowest level. Above that, utilities such as ping, telnet,
ftp, tftp and X are layered. Those top level layers are
optional, but all the layers and parts below TCP and
UDP are pretty much essential for normal system operation,
a large chunk of code. All the RFC's for the spec, the
whole stack in fact, are in the public domain and have
been for decades.
Originally, all that was loosely based on an ISO model,
the sort of standards that DEC were great supporters
and contributors to at all levels, but really backed
themselves into a corner over decnet. An obscure set
of protocols and command set reminiscent of the sort of
serisl line and telco ideas dating back to the 1970's.
TCP/IP was faster, easier to visualise in design, to
program and above all, a completely open source and fixed
set of standards that anyone could use, improve and generally
contribute to.
Long term, closed source sytems are dead, other than for
specialist applications, but it will take brave vendors
to contribute their systems to the commen good, after
decades of secrecy and client lockin...
TCP/IP is is just one layer of a stack of networking
parts that are designed to work together, a very
elegant and well engineered design. TCP, along with UDP,
are layered above IP, ICMP and IGMP, which in turn are
layered above the data link layer and hardware at
lowest level. Above that, utilities such as ping, telnet,
ftp, tftp and X etc are layered. Those top level layers are
optional, but all the layers and parts below TCP and
UDP are pretty much essential for normal system operation,
a large chunk of code. All the RFC's for the spec, the
whole stack in fact, are in the public domain and have
been for decades.
Originally, all that was loosely based on an ISO model,
the sort of standards that DEC were great supporters
and contributors to at all levels, but really backed
themselves into a corner over decnet. An obscure set
of protocols and command set reminiscent of the sort of
serisl line and telco ideas dating back to the 1970's.
TCP/IP was faster, easier to visualise in design, to
program and above all, a completely open source and fixed
set of standards that anyone could use, improve and generally
contribute to.
Long term, closed source systems are dead, other than for
specialist applications, but it will take brave vendors
to contribute their systems to the common good, after
decades of secrecy and client lockin...