Subject: [arch-d] A summary of Pekka's position so far

From: Pekka Nikander <[email-masked]>
Date: Mon, 4 Dec 2006 10:38:00 +0200

I've been one of the more vocal people on this discussion, apparently  
presenting opinions that may appear self-contradicting to some  
people.  I've posted almost 30 messages, and altogether there's been  
some 450 messages during the last month.  Hence, a summary may help.

As I have a position that clearly differs from what some other people  
have, I try to summarise only my position.

Executive summary
-----------------

First and foremost, I think that we need to work on BOTH a short/ 
medium term solution AND on the longer term solution space in  
parallel, both tasks continuously learning from each other.   Form  
the short/medium term point of view, I think something along the  
lines of HIP and/or SHIM6+CGA would help with a large number of  
current problems, including the scalability of the routing system and  
dealing with middle boxes; see below.  From the longer term point of  
view, I'm afraid that we will need to look at completely new  
paradigms, leaving back, at minimum, some of our *assumptions* about  
the send-receive packet *semantics*.

As a second point, I have made a number of architectural  
observations, related to naming, flat name spaces, and mobility and  
multi-homing; see the end of this message.  Of those, I think the one  
on mobility and multi-homing is the most important one, as it  
apparently appears counter-intuitive to many people.

Personally, I have a very good feeling that we've managed to start  
this discussion.  So far the discussion has ranged far and widely,  
and I believe such wider mental exploration is still needed.   
However, simultaneously, it starts to look like to me that we may be  
able to identify some more focused threads amongst them all.

HIP / SHIM6 remedies
---------------------

Adding a new name space according to the HIP or SHIM6+CGA principles  
would help with at least the following issues, and probably more

---------------------------------- 
+---------------------------------------+
Issue                             | Why HIP / SHIM6+CGA may  
help          |
================================== 
+=======================================+
Scalability of the routing system | Separation of addressing from  
naming, |
                                   | allowing more flexible  
addressing     |
---------------------------------- 
+---------------------------------------+
Mobility and Multi-homing         | A new natural layer of  
indirection    |
---------------------------------- 
+---------------------------------------+
NAT, IPv4/v6 interop, etc.        | A name space above IPv4/v6  
addresses  |
---------------------------------- 
+---------------------------------------+
Some forms of bad traffic         | Cryptographic names allowing  
better   |
                                   | control on what to  
receive            |
---------------------------------- 
+---------------------------------------+
Sub-network naming and mobility   | Ability to delegate &  
thereby         |
                                   | aggregate*  
names                      |
---------------------------------- 
+---------------------------------------+
Flexible application naming       | Ability to delegate &  
aggregate       |
---------------------------------- 
+---------------------------------------+

*) Note that the name aggregation (via delegation) as implementable  
with HIP / SHIM6+CGA is very different from current address aggregation.

In detail, my main points so far have been the following ones.

1. Need for working towards BOTH a short/medium term AND long term  
solutions
------------------------------------------------------------------------ 
----

The systems theoretic observation that the IETF, as an organisation,  
may be addicted to short-term solutions.  There is nothing evil or  
even bad implied by this observation; I merely tried to state what I  
think seeing.

See http://www1.ietf.org/mail-archive/web/architecture-discuss/ 
current/msg00443.html

If that observation is true, the corollary is that we will need to  
work very consciously at two different tracks at the same time:
1. One track aiming for a short/medium term "good band aid"  
solution.  Time span: 3-8 years.
2. One track aiming for a long term "fundamental" solution.  Time  
span: 10+ years.

See http://www1.ietf.org/mail-archive/web/architecture-discuss/ 
current/msg00461.html

In working on the different solutions, we need to understand that  
parts of the network evolve at different rates:

See http://www1.ietf.org/mail-archive/web/architecture-discuss/ 
current/msg00479.html
and http://www1.ietf.org/mail-archive/web/architecture-discuss/ 
current/msg00797.html

And finally, I made a fundamental observation w.r.t our current  
thinking and systems: the techno-economic reality is that the way the  
Internet used to work will never again come back.

See http://www1.ietf.org/mail-archive/web/architecture-discuss/ 
current/msg00873.html

2. Identifier/locator split a la HIP/SHIM6+CGA would be good short/ 
medium term solution
------------------------------------------------------------------------ 
--------------

Some background reasoning why the addressing and routing systems are  
interrelated:

http://www1.ietf.org/mail-archive/web/architecture-discuss/current/ 
msg00662.html

Why some kind of an identifier/locator split (like HIP or SHIM6)  
would help in the short/medium term problem:

http://www1.ietf.org/mail-archive/web/architecture-discuss/current/ 
msg00837.html
http://www1.ietf.org/mail-archive/web/architecture-discuss/current/ 
msg00872.html

3. Observations related mostly to the long term solution space
--------------------------------------------------------------

A. What naming layers there should be: http://www1.ietf.org/mail- 
archive/web/architecture-discuss/current/msg00657.html

B. Thoughts about flat identifier spaces and their scalability:  
http://www1.ietf.org/mail-archive/web/architecture-discuss/current/ 
msg00779.html

C. Mobility and multi-homing are essentially similar from an  
architectural PoV: http://www1.ietf.org/mail-archive/web/architecture- 
discuss/current/msg00712.html

D. What we should be identifying, both from a long term and shorter  
term PoV: http://www1.ietf.org/mail-archive/web/architecture-discuss/ 
current/msg00841.html

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