[e2e] Protocols breaking the end-to-end argument

John Day day at std.com
Sun Oct 25 04:55:57 PDT 2009


At 23:59 -0400 2009/10/24, Noel Chiappa wrote:
>     > From: John Day <day at std.com>
>
>     > It would be a little hard for the e2e paper in 1982 to be about the
>     > CLNP/TP4 vs TCP/IP debate if half the debate didn't exist.
>
>Umm, I didn't say that the E2E paper was about the CLNP/TP4 vs TCP/IP 'debate'
>(competition would be more accurate, I think). You seem to be conflating my
>comments on two entirely separate points.

No, you are the one who is conflating.  The original point that I 
made was about the context in which the e2e paper was written.What 
was happening leading up to it.

>
>One was that for _some_ of us, the only 'ISO protocol war' we saw was the
>CLNP/TP4 vs TCP/IP competition.

This may be how it appeared in your corner of the world and when you 
appeared in the discussion.  By the time you got to MIT, this had 
been going on for some time.

The protocol wars began in 1975 (or thereabouts) when we learned that 
CCITT was developing X.25 and we tried to get datagrams put it into 
it.

In fact, the TCP vs "TP4", i.e. CYCLADES TS, debate had been over for 
4 years at that point.  THAT debate had been carried out between 1974 
and late 1977 in IFIP WG6.1 (INWG) where several Transport protocols 
(not just those two) were discussed and analyzed. WG6.1 was managing 
at least a couple of meetings a year at that time. There were many 
participants from the US (APRANet/Internet) and Europe.  The result 
was INWG96  published at Danthine's conference in early 1978.  As far 
as we were concerned that ended the transport protocol discussion. 
(Note that INWG 96 was authored by people from all sides of the 
discussion:  Cerf (Internet), MacKenzie (Internet),  Scantlebury 
(NPL), and Zimmermann (INRIA).  As far as we were concerned there 
never was a TCP/TP4 war, that issue was resolved before the standards 
battles started in earnest.

Of course, now we know that neither was the best choice and that 
delta-t was far superior to both.

As far as the "IP" discussion, we were pretty happy with that.  The 
only things we knew we needed to do for a world wide protocol was a 
bigger address field and fix the problem that had arisen in 1972 with 
Tinker AFB.  We needed to name the node rather than the interface. 
No one saw this as a big deal.   XNS, CYCLADES, DECNet, EUNet had all 
done that.  (I always contend that the ARPANET didn't so much get it 
wrong as we had a lot of other things to worry about and it was 
first.)

This is why I was so shocked when the IETF refused to name the node 
in 1992.  We had known about the issue for 20 years.  Everyone else 
had by then fixed it.  That was when it became clear that the IETF 
had become more a craft guild than an engineering group and relied 
more stock in tradition. Actually, it had begun before that but as 
they say the third time is the charm.

But again here we were still to attached to the beads-on-a-string 
model that we thought we had refuted.  There was a further 
simplification that we couldn't see at that point.

>
>The other was that the E2E paper was not principally intended as firepower in
>the TCP/IP vs X.25 debate, but rather was more intended to be exactly what
>the passage of time has shown it to be - a contemplation of the underlying
>fundamentals of functionality placement, one which would be of lasting value.

It certainly spends a lot of space arguing that point.  In fact, in 
the period leading up to its publication what other issue of what to 
put in the network vs the hosts was being debated?  As I said, I have 
always seen the e2e paper as an attempt to create a more general 
principle to refute that hop-by-hop error control could supplant e2e 
error control.  And by having a more general principle that when 
other things were proposed for "in the network" there would be 
something we could point to.

I am afraid that your (and Abbate's) perspective on what game was 
afoot was very narrow and taken out of context with the war as a 
whole.


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