Subject: Re: [rrg] Terminology

From: [email-masked]
Date: Thu, 4 Feb 2010 15:18:02 EST

Imho, it would be wrong to go for an architecture which either says "I  am  
network-based" resp. "I am host-based". The right architecture is  
something which discovers and serves the needs of the network layer as such  i.e. 
which considers both routers and hosts  and assigns  them the appropriate task.
 
It would be important to overcome the orthogonality between intra- and  
inter-domain routing and it would be awfully bad to install another  
orthogonality being CES-versus-CEE.
 
Heiner

In einer eMail vom 04.02.2010 16:50:33 Westeuropäische Normalzeit schreibt  
[email-masked]:

> From: Tony Li <[email-masked]>

> To me,  CES seemed to be 'map-and-encap' and CEE was 'everything else'.

> From: Scott Brim <[email-masked]>

> it seems that some approaches just don't fit in it.

If something  represents a set of choices along a number of orthagonal axes
(e.g.  'map-and-encaps' plus 'invisibly map in proxies' plus 'caching
mappings'  plus etc etc), then it may be useful to give that _set_ of 
choices
a  name.

However, with terminology which labels one particular set of  design choices
'{set X}', but then goes on to label everything else  'not-{set X}', the
latter term is not at all useful. It is kind of like  saying that my name is
'not-Tony-Li'. The problem is that in such a system,  everyone else (except
Tony :-) is also named 'not-Tony-Li' - and that is  not very useful for
distinguishing among all the (very different :-)  individuals who are not
'Tony Li'.

Equally importantly, if you have  a design choice _axis_ (e.g. caching 
versus
non-caching), different points  on that axis can usefully be named.

But 'not-{set X}' names are not  useful.

> From: Scott Brim  <[email-masked]>

>> "The CES vs. CEE  distinction does not arise from whether hosts are
>>  altered or not. It arises from the fundamentally different  mechanisms
>> which are used by these two different  types of architecture to achieve
>> scalable  routing."

> the two different approaches it  distinguishes between are to separate
> edge  routing/addressing from non-edge and eliminating the distinction.

If  your summation is right, I think I'm starting to grasp what these terms
are  trying to get at, and it might be useful architectural  terminology.

> But that's just one criterion, and not  every approach benefits from its
> use.

Sure, just  like the 'cache mappings' versus 'full distribution of  
mappings'
distinction doesn't apply if you don't have a system with things  like xTRs
which handle the mapping process for large groups of entities.  But that is
still an axis of architectural choice, just one that doesn't  apply to all
potential designs.

But even if CEE/CES does not apply  in all cases, that does not mean it is 
not
an axis (as opposed to a  description of a particular set of design 
choices).
>From your summation  above, it seems like it might be...

Noel
_______________________________________________
rrg mailing  list
[email-masked]
http://www.irtf.org/mailman/listinfo