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Re: [IETF] Re: IPv6 deployment [was Re: Recent Internet governance events]

2013-11-22 16:51:09
On Fri, Nov 22, 2013 at 2:24 PM, Ralph Droms 
<rdroms(_dot_)ietf(_at_)gmail(_dot_)com> wrote:


On Nov 22, 2013, at 5:12 PM, Warren Kumari <warren(_at_)kumari(_dot_)net> 
wrote:


On Nov 22, 2013, at 6:11 PM, Ted Lemon 
<ted(_dot_)lemon(_at_)nominum(_dot_)com> wrote:

On Nov 22, 2013, at 2:29 PM, Phillip Hallam-Baker 
<hallam(_at_)gmail(_dot_)com> wrote:
They will scale fine just like the dialup pools have scaled fine.

Dialup pools are stateless.   CGNs are stateful.   They do not scale the 
same way.   This is not to say that you _can't_ scale CGNs—

So, something that has always confused me abut the CGN deployment 
discussions and scaling is the number of customers (victims?!) that people 
want to put behind an IP…

Warren - thank you for asking this question.  I asked it for several years, 
never got a satisfactory answer (never got much of any answer, really) and 
stopped asking...

- Ralph


Here is a hint 
http://www.flickr.com/photos/ericsson_images/10795593603/in/set-72157637442787564

Oh, and, here is a usecase:  Network operator wants to start are
regional mobile network in Europe or APAC:  APNIC or RIPE will give
you a /22 for your entire business.

CB


CB


If you are an operating ISP with e.g a /18 you can have ~16,000 
customers[0]. Great, you are still growing, and want to add another 10,000 
users, good for you.
For some reason at this point many ISPs start talking about putting on the 
order of 100s of users behind an IP, then the discussion turns into port 
starvation and scaling and such…


What's wrong with putting 2 users behind each IP? Are you really planning on 
doubling your size *before* significant advances in v6 deployment and CGN 
scaling come about? Yes? Ok, so put 4 users behind one IP (note, I did not 
say "device") -- are you really planning on quadrupling in the next few 
years? And if so, are you hiring? :-P

Seriously, I don't get the "If we deploy CGN's we have to cram as many users 
behind one address as possible…" bit -- can anyone enlighten me?

I've run some big NATs (for example, for AOL's corporate network) and yes it 
sucks, but you can minimize your (and your customer's) pain by overloading 
as little as possible….


it's just easier to scale stateless-core NATs.   I say this based on zero 
operational experience, of course... :)

Sure, fair 'nuff, no argument here….

W
[0]: Yes, yes, handwave, handwave, packing issues, infrastructure space, 
etc. Been there, run a network… Skipping all that for easy of discussion.


--
There were such things as dwarf gods. Dwarfs were not a naturally religious 
species, but in a world where pit props could crack without warning and 
pockets of fire damp could suddenly explode they'd seen the need for gods as 
the sort of supernatural equivalent of a hard hat. Besides, when you hit 
your thumb with an eight-pound hammer it's nice to be able to blaspheme. It 
takes a very special and straong-minded kind of atheist to jump up and down 
with their hand clasped under their other armpit and shout, "Oh, 
random-fluctuations-in-the-space-time-continuum!" or "Aaargh, 
primitive-and-outmoded-concept on a crutch!"
 -- Terry Pratchett