RE: v6ops:IPv4 vs. IPv6 operational costs

["Sofia, Rute" <rute.sofia@siemens.com>]

Hello,

Considering IPv4, a NAT "serves" two purposes: from a basic perspective,
either within the operator's net (to deal with overlapping IPs) or to
allow a set of devices to achieve global IP connectivity by means of a
single (globally routable) IP address.

Assuming that you are referring to the most popular option - the second
- then using a NAT requires workarounds to allow bi-directionality and
to cope with applications that embed IP addresses in the payload. Being
a translation solution, the first problem is that it adds entropy to the
end-to-end path. Notice that in most cases, translation may be required
in more than one point. Furthermore, ALGs have to be developed for
already existing applications, or new applications *must* consider that
a NAT is in the way. Or, NAT traversal techniques (STUN, etc.) can be
applied but again, there is always entropy added.
Is it very hard to deploy an ALG, or to rely on NAT traversal
techniques? Not really, but the problem is again: entropy added to the
end-to-end path and each time a new application emerges, one has to find
a way to deal with the NAT...this means that new services are now in
most cases dictated by the NAT existence which is pretty limitative.
Imagine trying to place in the future multicast sources behind a NAT,
for instance...or using mobility...

I do not know if it's possible to "quantify" the operational costs of
NAT+private addressing vs. IPv6. In fact, IMHO that does not really make
sense. Particularly because the operator has no chance to really reach
anything behind a NAT - unless you are referring to the use of a NAT
somewhere in the access, not in the extremes, as mentioned.

So, IMHO, what can be compared: the possibility of having *global*
connectivity per device - new services will for sure appear. And, due to
autoconfiguration it is possible to simplify the operations required to
provide connectivity to a group of devices. Despite the fact that such
features may or not be complete within the current standards - they are
not - the fact is that IPv6 autoconfiguration is one of the most
interesting features IPv6 has.

Regards,
Rute

 

> -----Original Message-----
> From: owner-v6ops@ops.ietf.org 
> [mailto:owner-v6ops@ops.ietf.org] On Behalf Of Dwight Jamieson
> Sent: Wednesday, November 23, 2005 7:47 PM
> To: Pekka Savola
> Cc: v6ops@ops.ietf.org
> Subject: RE: v6ops:IPv4 vs. IPv6 operational costs
> 
> Pekka,
> 
> Looking a few years down the road, assuming that bulk of the 
> bleeding is
> over, will operating that network be simpler, easier, cheaper than
> operating a network with private addressing today?
> 
> How painful is introducing new applications behind NAT/ALGs? What
> percentage of an IT department's budget spent on issues relating to
> private addressing?
> 
> 
> -----Original Message-----
> From: Pekka Savola [mailto:pekkas@netcore.fi] 
> Sent: Wednesday, November 23, 2005 1:33 PM
> To: Jamieson, Dwight [CAR:NP10:EXCH]
> Cc: v6ops@ops.ietf.org
> Subject: Re: IPv4 vs. IPv6 operational costs
> 
> 
> On Wed, 23 Nov 2005, Dwight Jamieson wrote:
> > Is anyone aware of any studies that quantify the 
> differences between 
> > the operating costs of an IPv4 network using private 
> addressing vs. an
> 
> > IPv6 network using globally unique addresses?
> 
> I've not but I'd be interested to see _real_ calculations.
> 
> I assume from your wording that you're referring to an IPv6-only 
> network.  If so, my suspicion is that the costs can be high as you 
> need to live on the bleeding edge, i.e., are the one that'll find the 
> bugs, need to get a lot of consulting to get the network to work as 
> v6-only, etc.
> 
> -- 
> Pekka Savola                 "You each name yourselves king, yet the
> Netcore Oy                    kingdom bleeds."
> Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings
> 
> 
>