Subject: [arch-d] Valid and Invalid Internet architectures and approaches

From: "Fleischman, Eric" <[email-masked]>
Date: Wed, 7 Dec 2005 14:49:33 -0800

Friends,

Several months ago I stumbled upon a middlebox implementation that I
believe is a classic example of being a "misbehaving middlebox", despite
the fact that the approach is blessed by RFC 2401 and 2401bis (i.e.,
IETF standards). 

I created an array of technical arguments for this characterization,
including the fact that the approach simply doesn't operationally work
because it explicitly segments the network for which an onerous unicast
work-around exists but no multicast work-around exists. Thus, it
effectively "breaks" IP with no current remedy at all. This operational
argument didn't resonate with the RFC 2401bis editor but my
architectural arguments did somewhat. 

Thus, in order to build up better support for that line of reasoning, in
the hopes that 2401bis may hopefully support a more viable design, I
engaged many of you through two generic queries to the IETF mail list
("Question about the normative nature of IETF RFCs" and "Correct
middlebox behavior"). The responses I received from these queries didn't
result in consistent replies, leading me to conclude that the IETF no
longer has a group consensus about these issues.

Concerned about this possibility, I spent much of the recent Vancouver
IETF talking with long-term IETF members about whether the Internet and
the TCP/IP protocol suite currently has an architecture or not. The
consistent (or, rather, unanimous) response was that it does not.
Specifically, whereas we could assert underlying architectural
principals upon which IP and the Internet were built as recently as
eight years ago, and thereby identify "good" and "bad" approaches, the
current "Wild West" evolution since then (e.g., convergence with SS#7
telephony and video networks; widespread middlebox deployments; an
inability to distinguish between middleboxes, host, and router
functionality; tunneling of various sorts without viable network
management mechanisms; etc.) has resulted in an ad hoc creation lacking
unifying constructs. Without such a foundation, I was told, how can we
therefore talk about "good" or "bad" or "misbehaving"? So I asked them,
if we indeed don't have any common foundation anymore, then what
confidence do we have that our current system will continue to remain
viable over time? Nobody provided me with any reassurance. Some pointed
to GENI Project or other research activities as perhaps re-establishing
a foundation to which the Internet could migrate over time. However, no
answer was believable by a long-term operational guy like me.

I can't imagine that our community really has thrown up its hands and
embraced dissonance and brownian motion. But unless we can articulate an
architecture, I do not understand how we can evolve the Internet in a
rational fashion. We could perhaps hope that "local self interest" is
ultimately maximized when approaches that benefit the majority are
chosen. However, this is not always true and "benefits to the majority"
is not something that can really be determined without an architectural
foundation.

Needless to say, I ultimately lost my argument with the 2401bis editor.
However, I would hate to learn that I may someday also lose the
Internet. Can you provide me with any hope that this will not happen?

--Eric

_______________________________________________
Architecture-discuss mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/architecture-discuss

---

From: Tony Li <[email-masked]>
Date: Wed, 7 Dec 2005 15:02:05 -0800

On Dec 7, 2005, at 2:49 PM, Fleischman, Eric wrote:

> embraced dissonance and brownian motion.

Eric,

This has been clearly and repeatedly stated.  The usual situation is  
that
we have conflicting technologies to achieve some goal and we choose
to "let a thousand flowers bloom" or "let the market decide".

Tony

---

From: George Gross <[email-masked]>
Date: Wed, 7 Dec 2005 17:42:50 -0500 (EST)

Hi Eric,

> architectural arguments did somewhat.

I am highly familiar with the RFC2401-bis text for multicast, as I
contributed some of the text for it ;o) I am also a co-author for the MSEC
IPsec extensions draft. So I'd appreciate hearing more about your
middlebox problem, either on or off this list as you see fit.... BTW
section 5 of the msec-ipsec-extensions draft elaborates on IPsec multicast
interactions with NAT at length.... yes, it is a swamp ;o(

> longer has a group consensus about these issues.

There is alot of inertia (read prior investment) in existing RFC2401 and
RFC2401-bis products. The only IETF activity that I've seen having a shot
at sidestepping the inherent limitations of IPsec is the HIP effort. But
it appears to me that shim6 is going to eclipse HIP.

> is not something that can really be determined without an architectural

these days, $$$ talks louder than the Internet architects ;o( I observe
that unlike a decade ago, the Internet has many competing players and
cabels. their interests are not altruistic and they are locally optimized.
Consequently, there is no effective method (other than $$$)  that I've
seen yet that could ratify and deploy a unified next-gen Internet
architecture at the IP layer.

The only technical avenue I see is to use IP as a virtual link layer under
HIP or a cousin of HIP, and combine it with a (fill-in the blank) killer
app that is a catylst for rapid adoption. Eric, got a killer app handy?

hth,
	George