Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!ucsd!ucbvax!UDEL.EDU!Mills
From: Mills@UDEL.EDU
Newsgroups: comp.protocols.tcp-ip
Subject: Re:  Running out of Internet addresses?
Message-ID: <8812061258.aa12359@Huey.UDEL.EDU>
Date: 6 Dec 88 17:58:22 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 22

Vint,

You may have heard me honk this subject before, but my feeling is to
byte the bullet and adopt variable-length type-E addresses and encode
them as per ISO NSAP. From my implementation esperience variable-length
addresses are maybe a little awkward, but not really hard when compared
to variable-length options, etc. The ISO NSAP addressing format includes
a length/format identifier, so it is in principle possible to adopt this
format, even if the format is not completely decoded by all gateways,
by teaching the header-parser code how to leapfrog the address field
in order to parse the options. The big win in my view is the possibility
of carrying additional baggage, such as authority, policy and so forth
encoded in the address field (perhaps in the IDP field).

In my opinion we should face this issue squarely and right now. A statement
like: in the future the Internet may be forced to adopt variable-length
addressing. If so, it will be expressed in an ISO encoding as a type E
format (at least the high-order three bits). Host and gateway implementors
should bear this in mind as they implement header-parsing algorithms and
data structures. Or something like that.

Dave