---------- Forwarded message ----------
From: Charrie Sun <charrie...@gmail.com>
Date: 2010/1/19
Subject: Re: [rrg] Fwd: Critique of LMS and GLI-Split
To: Lixia Zhang <li...@cs.ucla.edu>
Hi Lixia,
I think the biggest difference between LISP+ALT and LMS is that mapping
nodes in LMS are not only indexing nodes but also the final authorities of
mapping data. This correlates tightly with the question that whether the
separation should be placed at the core or the edge. In LISP separation work
in at the edge to facilitate TE etc, thus letting ETRs to be the mapping
authorities would not bring so many problems as those in the cores doing
separation. Since in the latter case, if an edge is multihomed to several
ISPs and thus connects to ETRs at different ISPs, no ETR would like to store
mapping data for its customer and its opponents. However, routers in edge
networks may often not hold a whole global routing table and they set
default route to their providers to reach the outside world, thus I assume
they may not see the scalability problem that serious as core routers. In
this sense, edge routers may not have much incentives to upgrade, to be
ITRs and ETRs.
In LMS the mapping system is independent of ISPs and they charge for
their mapping services, forming a new interest group. ISPs as well as edge
networks whole join the circle can benefit immediately with few changes
(core routers may do tunneling, edge networks need no changes while they are
willing to inform mapping information to the mapping system to realize TE).
I mainly concerned the economic model here.
Compared with ALT, I think we only share the hierarchical struture, while
the content the mapping system holds and the economic model is different.
Thank you very much for your opinions!
Best wishes,
Letong
2010/1/19 Lixia Zhang <li...@cs.ucla.edu>
the text version is indeed much better for many people I believe (though
> there still seem some strange char's in the text)
>
>
>
> On Jan 18, 2010, at 7:27 PM, Charrie Sun wrote:
>
> Hello all,
>> Since no one has written a critique of my LMS, I queried my workmates
>> and wrote a critique on it. As many people have pointed out, LMS is a
>> mapping mechanism and does not itself constitute a whole solution for the
>> scalability problem. Well the mechanism is based on edge-core separations
>> and can incorparate with proposals that need a global mapping system, to
>> enhance its functionalities.
>> I also wrote a brief critique on GLI-Split, since I think the two
>> separation planes it clarifies, including the separation between identifier
>> and locator and the separation between local and global locator, can meet
>> different needs of ISPs and hosts. I had some discussions with Dr. Menth and
>> wrote the critique based on the discussions and rethinking. Welcome for
>> complement and rectifications on mine.
>> Attached is my critiques and warmly welcome for comments.
>>
>
> it seems to me that a major missing issue in LMS critique is an
> articulation on the novelty: given this design is long after LISP-ALT, what
> are the fundamental differences/new gains in LMS?
>
> I read through the paper your summary pointed to (
> http://www.ietf.org/mail-archive/web/rrg/current/msg05491.html). Section
> 5 stated that
>
> "The idea is similar to LISP+ALT while differs from it in several ways:
> (1) As previous stated we place ETRs at the core, while LISP+ALT places
> them at the edge;
> (2) MNs maintain mapping data instead of ETRs.
> (3) the structure is explicitly designed as to the layer number and node
> degrees, which is unclear in LISP-ALT.
> (4)ITR buffers the arriving packets when its cache failed to find a
> mapping. In LISP+ALT now the implementation is just to drop the packets."
>
> None of the above points looks like essential to me.
>
> Wonder what I missed?
>
> Lixia
>
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