[e2e] What if there were no well known numbers? (history)

[John Day]

Just to get the record straight.  Sitting at Illinois, we immediately 
saw well-known sockets as I said, "hard-wiring low core" but a 
necessary kludge because we didn't have time to do it right with 
application names and we didn't have all that many applications and 
we could do it right later (those famous last words of many projects).

The story that is being painted here is that this view was in the 
vast minority, that most people saw well-known sockets as a quite 
reasonable general solution for the long term (as it has turned out 
until the web came along that is.)

I don't mind changing my view, although my perspective is more 
flattering of the ARPANet guys who did it than the picture being 
painted here.

Take care,
John


At 4:04 +0000 2006/08/05, Greg Skinner wrote:
>On Fri, Aug 04, 2006 at 10:00:33PM -0400, John Day wrote:
>>  I remember that we had already had conversations about
>>  application-names and network addresses and a directory.  I know that
>>  a lot of our thinking was using operating systems as a guide to how
>>  to do it.  But since we only had 3 applications and only one
>>  occurrence of each per host, and we needed to get something up and
>>  running, there wasn't time to do it right.  Perhaps we were having
>>  these conversations with people other than the UCLA people.  Maybe it
>>  was the Multics crowd.  I can believe that in the very very early
>>  days that was the logic, but by 1970 or so, we knew better.  From
>>  about then, I always considered well-known sockets to be the
>>  equivalent of "hard-wiring low core."
>>
>>  A kludge.
>>
>>  The port numbers in TCP and NCP function as a connection-identifier
>>  within the scope of the (src, dest) addresses, i.e. it distinguishes
>>  multiple connections/flows between the same two points.  They do not
>>  identify applications.  The well-known idea is just an expedient
>>  convention.  It clearly doesn't generalize unless you are McKenzie
>>  who believed that Telnet and FTP were all you needed. ;-)
>
>I wasn't involved in any of the ARPANET R&D, but I was able to piece
>together a bit from the old RFCs.  The socket as connection identifier
>made its debut in RFC 33.  It was a 8-bit field called AEN (Another
>Eight-Bit Number).  The idea that there should be a "directory"
>of sockets appeared in RFC 65.  Jon Postel posed the question of
>whether standard protocols should have assigned/reserved socket
>numbers in RFC 205.  The first call for well known socket numbers came
>in RFC 322 (accompanying a concern about which socket numbers were
>currently in use at which hosts).  JP proposed that he be the "czar"
>for standard socket numbers in RFC 349.  So it seems as if well-known
>sockets were an expediency, as you say, which was preserved in TCP and
>UDP.
>
>BTW, speaking of hosts.txt, RFC 226 contained the first cut at an
>"official" hosts list.  (Before that, the RFC noted that each telnet
>implementation provided its own list of host names.)
>
>--gregbo