Subject: [rrg] and while we're at it, here's a view from the ground...

From: David Meyer <[email-masked]>
Date: Thu, 30 Oct 2008 07:54:48 -0700

http://www.1-4-5.net/~dmm/iteotwawki-ipam-mraws3.pdf

	Dave
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From: "William Herrin" <[email-masked]>
Date: Thu, 30 Oct 2008 14:17:58 -0400

>        http://www.1-4-5.net/~dmm/iteotwawki-ipam-mraws3.pdf

David,

Good summary. Couple comments:

Slide 15:
End-to-end = peer to peer. You'll be better understood with the more
widely used term.

Slides 15 and 17:
I suspect you have overstated the dollar and failure cost impacts of
carrier grade NAT. Has anyone attempted a systemic cost analysis?

Regards,
Bill Herrin

-- 
William D. Herrin ................ [email-masked]  [email-masked]
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004
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From: David Meyer <[email-masked]>
Date: Thu, 30 Oct 2008 13:25:41 -0700

> Good summary. Couple comments:

	Thnx.

> End-to-end = peer to peer. You'll be better understood with the more

	I meant end-to-end.

> carrier grade NAT. Has anyone attempted a systemic cost analysis?

	Well, those building them and those planning to deploy
	them. 

	Dave

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From: "William Herrin" <[email-masked]>
Date: Thu, 30 Oct 2008 17:34:26 -0400

David,

If you asked an audience of system administrators whether Vonage and
Skype would be impacted by fracturing the end-to-end principle with
carrier grade NAT, I'm not sure how many would correctly identify that
Skype would be impacted but Vonage would not. I think most would
incorrectly believe that all VoIP systems would be hurt, not just the
ones structured in a peer to peer design.

I presume you know your audience better than I do. I would merely
suggest that an imprecise term your audience understands is often a
better choice than a precise one whose implications they don't really
get.

>  Well, those building them and those planning to deploy them.

URL please?

Seriously, what passes for cost analysis in this industry is shameful.
Mostly it's "experts" sitting in a circle making SWAGs. If this time
is an exception, I'd like to read the paper.

Regards,
Bill Herrin

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From: "Templin, Fred L" <[email-masked]>
Date: Thu, 30 Oct 2008 14:50:14 -0700

Dave,

I don't understand the red-ink assertions about dual-stack;
are you meaning to blame the network for lack of IPv6 uptake
while application transition to IPv6 has been lagging?

Fred
[email-masked]  

>-----Original Message-----
>From: David Meyer [mailto:[email-masked]] 
>Sent: Thursday, October 30, 2008 7:55 AM
>To: [email-masked]
>Subject: [rrg] and while we're at it, here's a view from the ground...
>

---

From: David Meyer <[email-masked]>
Date: Thu, 30 Oct 2008 15:28:01 -0700

> better choice than a precise one whose implications they don't really

	Fair enough.

> >  Well, those building them and those planning to deploy them.

	Don't have one (yet).

> is an exception, I'd like to read the paper.

	What I know is public is the following:

	(i).	A+P

		http://www.1-4-5.net/~dmm/a+p.pdf

	(ii).	All of the IETF stuff

		softwire, behave and coexist work
		http://www.ietf.org/internet-drafts/draft-nishitani-cgn-00.txt
		...

	I'm sure you'll see stuff from vendors and SPs but my
	sense is that its just too early at the moment.

	Dave

---

From: David Meyer <[email-masked]>
Date: Thu, 30 Oct 2008 15:29:30 -0700

> while application transition to IPv6 has been lagging?

	Fred, 

	I'm not blaming anything. I'm not taking a position on
	any of this stuff. I'm merely reporting on what I observe
	going on on the ground.

	Dave

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From: "Templin, Fred L" <[email-masked]>
Date: Thu, 30 Oct 2008 15:37:23 -0700

Dave, 

>Sent: Thursday, October 30, 2008 3:30 PM
>To: Templin, Fred L
>Cc: [email-masked]
>Subject: Re: [rrg] and while we're at it, here's a view from 
>the ground...
>

I was reacting to what I perceived as a certain tone in
some of the assertions, but when you say that you are not
taking a position I take you at your word.

One thing I will point out is that emerging solutions
like dual-stack-lite and CGN are not necessarily mutually
exclusive wrt what has traditionally been known as "dual
stack"; this is documented in RANGER.

Thanks - Fred

---

From: "William Herrin" <[email-masked]>
Date: Thu, 30 Oct 2008 19:31:49 -0400

>                http://www.1-4-5.net/~dmm/a+p.pdf

Hi David,

So you shift a few bits of the UDP and TCP port numbers into the
addressing space, lets say 4 bits, giving a 16x multiplier on the
usable space in exchange for each host "only" being able to have 4000
active ports. Anyone with an A+P compliant host gets a global address
that preserves the end-to-end principle, at least for UDP, TCP and the
related ICMP errors. Legacy hosts get rfc 1918 space, fall into the
CGN and still work fine for most stuff. Other IP protocols fail, of
course, but then they fail with a CGN too.

Very clever.

The only word about cost was an observation that ignoring
out-of-bounds ports would be less costly than dealing with them.

>                http://www.ietf.org/internet-drafts/draft-nishitani-cgn-00.txt

Didn't find an instance of the word "cost" in here. Wouldn't expect to
in an I-D.

But then that's my point: most likely nobody has attempted to do a
real cost analysis on deploying and maintaining an Internet where the
residential accounts are mostly behind CGNs. A claim that such a
system will cause an alarming increase in cost is not well supported.

Given the crushing blow to P2P consumption and increased revenue from
the sales of static IP addresses, the delta cost could be zero or even
negative. I doubt it will be, but I also doubt it will be alarmingly
high.

Regards,
Bill Herrin

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From: Scott Brim <[email-masked]>
Date: Fri, 31 Oct 2008 11:51:47 -0400

> ones structured in a peer to peer design.

OK I'm one of them.  I thought Skype had STUN-like servers in order to
deal with NATs.  CGNs will affect all such servers but it will affect
them equally.  No?

swb

---

From: "William Herrin" <[email-masked]>
Date: Fri, 31 Oct 2008 13:05:39 -0400

> deal with NATs.  CGNs will affect all such servers but it will affect

Hi Scott,

Skype's primary mode of operation tries to fool the NATs on each side
into opening the port that the other side will use. Both clients
briefly communicate with a server to determine what the external UDP
source address and port is likely to be. Then the clients switch
communication to each other and hope the ports match. Behind a small
NAT with relatively little simultaneous UDP traffic, this works out
pretty well.

They finally added some servers to relay calls, yes, but they're the
last-ditch fallback and I believe they're only available to paying
members though I could have that wrong. Having to provide a lot of
these relay servers and the bandwidth that goes with them would
severely disrupt Skype's business model.

With Vonage, as I understand it, the phones talk to the Vonage
servers, not directly to the other Vonage phone. Their main problem is
keeping the translation alive without wasting too much bandwidth and
dealing with the few NATs that don't implement a generic UDP
translation due to port filtering or what have you. Unless there are
so many Vonage phones behind the NAT that the NAT runs out of sockets
to talk to Vonage, they really aren't affected by the size of the
network behind the NAT.

Regards,
Bill Herrin

---

From: Marshall Eubanks <[email-masked]>
Date: Fri, 31 Oct 2008 13:11:03 -0400

> NAT with relatively little simultaneous UDP traffic, this works out

This sounds very much like H.460, which is wide deployment with  
devices such as the
Polycom V2IU and, from my experience, works quite well even in heavily  
firewalled corporate environments.

Regards
Marshall