[TUHS] History of select(2)

Johnny Billquist bqt at softjar.se
Sun Jan 15 11:22:01 AEST 2017


On 2017-01-15 00:43, Noel Chiappa wrote:
>     > From: Johnny Billquist <bqt at softjar.se>
>
>     > And RFC791 is dated September 1981.
>
> Yes, but it had pretty much only editorial changes from RFC-760, dated January
> 1980 (almost two years before), and from a number of IEN's dated even earlier
> than that (which I'm too lazy to paw through).

Like I pointed out, RFC760 lacks ICMP. Error messaging was supposed to 
be carried in IP options. That is more than an editorial change.

>     > So I have this problem with people who say that they implemented TC/IP
>     > in 1978 for some reason.
>
> If you look at IEN-44, June 1978 (issued shortly after the fateful June 15-16
> meeting, where the awful 32-bit address decision was taken), you will see that
> the packet format as of that date was pretty much what we have today (the
> format of addresses kept changing for many years, but I'll put that aside for
> now).

Packet format, yes. Semantics and operations differed. ICMP didn't even 
exist.

>     > Especially if they say ... it was working well in heterogeneous
>     > networks.
>
> TCP/IP didn't work "well" for a long time after 1981 - until we got the
> congestion control stuff worked out in the late 80's. And IIRC the routing/
> addressing stuff took even longer.

Depending on how you defined "well", people might still argue about 
that. :-)

>     > I don't think it's correct to say that it was TCP/IP, as we know it
>     > today.
>
> Why not? A box implementing the June '78 spec would probably talk to a current
> one (as long as suitable addresses were used on each end).

I would seriously question that, if nothing based on just my comments 
about ICMP above.

Anyway, let's dig a bit more then, shall we...

RFC 762 is "Assigned numbers". There you will find that the IP version 
field in the IP header values. Version 4 was defined in August 1979, 
with a reference to: "Postel, J. "DOD Standard Internet Protocol," 
IEN-128, USC/Information Sciences Institute, January 1980."

Which also makes one question how anyone would have known about IPv4 in 
1978.

Also, first definition of TCP shows up in RFC 761, which is also 
IEN-129. And that is the DoD standard. Also dated January 1980.

Another rather interesting document is RFC 801, which lists the current 
status of TCP/IP implementations in appendix D. This document is from 
November 1981, and there it is clearly stated which implementations 
exist at that point (that the authors know about). And it's for the most 
part very much "work in progress". And this is at the end of 1981...

So yes, I still have problems with claims that they had it all running 
in 1978. :-)

>     > It was either some other protocol (like NCP) or some other version of
>     > IP, which was not even published as an RFC.
>
> Nope. And don't put too much weight on the RFC part - TCP/IP stuff didn't
> start getting published as RFC's until it was _done_ (i.e. ready for the
> ARPANet to convert from NCP to TCP/IP - which happened January 1, 1983).

I don't really agree with your view on the RFCs here. :-)

> All work prior to TCP/IP being declared 'done' is documented in IEN's (very
> similar documents to RFC's, distributed by the exact same person - Jon
> Postel).

Yes, except of course, those documents aren't really that much earlier 
in some cases, like ones I pointed out above, which I think are most 
relevant here...

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol


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