[ih] IEN's as txt
jnc at mercury.lcs.mit.edu
Thu Feb 9 16:48:43 PST 2017
> From: Paul Ruizendaal
> I did push IEN81 through an OCR tool with much the same result.
Not too surprising; the resolution and contrast in those scans is pretty
poor. Eyes can deal; computers, not so much.
> My underlying motive for this is to understand the changes to TCP (and
> IP/ICMP/UDP) in the 1978-1981 time frame ... Perhaps this analysis has
> already been done?
I don't think so, but maybe there's something I'm not aware of. You might try
reading the IEN meeting minutes from that period, to see what's documented
> if it was conceptual change it would seem odd that it did not show up
> earlier in the testing process
I honestly don't recall - maybe someone who was more active in TCP work can
speak to this.
> Same goes for ICMP: it was a late arrival and the rationale for
> abandoning the earlier approach is not entirely clear.
This I can speak to.
Before ICMP, the only protocol for exchanging information between hosts and
routers about the state of the network, was GGP, IEN-109. In that protocol,
inter-router messages/mechanisms (e.g. path computation) were mixed in with
router-host messages (destination unreachable, redirects, etc).
This was 'obviously bad' for several reasons. One of the major ones was that
it was obvious to us at that point that the routing was going to need a lot
of work, and we wanted to cleanly and clearly separate that all out.
Putting all the router<->host interactions in a separate protoocol was
clearly a desirable move, architecturally.
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