Reed's views, was [e2e] Cannara's views

David P. Reed dpreed at
Sun Apr 15 07:50:49 PDT 2001

At 10:54 PM 4/14/01 -0700, Cannara wrote:
>...Au contraire, TCP/IP was optimized for small MTU, 56kb/s, byte-oriented
>transfers, implemented on 16-bit machines that could do 32-bit (double-word)
>ops.  In other words, Telnet, RPC, FTP, etc.  TCP still counts bytes in
>sequence #s.  When all 3GBytes of Beethoven's symphonies can be ATMed in
>19sec, or OC48'd in 1 second, having a transport getting fooled by false
>congestion positives and dropping out for a second or so doesn't really make
>sense, no matter how many times we click our slippers and say: "I didn't
>optimize", "I didn't optimize"...

Huh?  To the extent this even makes some sense to parse, it is wrong.  The 
dominant early machines were PDP-10's - 36-bit machines - and there was a 
huge debate about "endian-ness" that pointed out the need for clear 
definitions in the protocols.  TCP counts bytes in sequence numbers, but 
there was a debate about going to 64-bits because we were worried that RTT 
might exceed the 8 gigabyte wraparound we had planned for.  So what?  Would 
counting ATM cells have been a few percent more efficient?

>..."Wholly false" -- so all new technology was anticipated, but ignored
>  Why,
>because clairvoyance was assigned no value?  What do you know of the future
>now that you're not telling us and that networking can safely ignore?  I can't
>imagine this is what you mean by "wholly false".

You're right. That's not what I meant.  So why are you putting words in my 

>   It's interesting that a
>networking system that, for instance, couldn't anticipate needing more than 32
>bits for addressing all those machines the future held, when Xerox already had
>implemented 80 in XNS, is somehow bestowing a "pay off".

No one is saying that all of the design choices were perfect.  Compromises 
don't work that way. The two biggest flaws in IP are the 32-bit addressing 
and the NSA-forced lack of end-to-end encryption.  (IMO, of 
course).  You're right that we knew about Ethernet's 48-bit 
addressing.  32-bits was a concession to the short-term thinkers at the 
time.   I was on the other side of these arguments, loudly in the first 
case, and more quietly in the second case - we wrote about it in the "end 
to end" paper, and my office mate did a complete design before being 
stopped by extraordinary pressure.  In both cases, compromise allowed the 
thing to get built.  Compromise is affecting the life of original IP.  This 
is the way the world works.

- David
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