North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: cost of dual-stack vs cost of v6-only [Re: IPv6 on SOHO routers?]

  • From: Leo Bicknell
  • Date: Thu Mar 13 10:54:33 2008

In a message written on Thu, Mar 13, 2008 at 03:26:48PM +0200, Pekka Savola wrote:
> On Wed, 12 Mar 2008, Leo Bicknell wrote:
> >ISP's are very good at one thing, driving out unnecessary cost.
> >Running dual stack increases cost.  While I'm not sure about the 5
> >year part, I'm sure ISP's will move to disable IPv4 support as soon
> >as the market will let them as a cost saving measure.  Runing for
> >"decades" dual stacked does not make a lot of economic sense for
> >all involved.
> So, can you elaborate why you think the cost of running dual stack is 
> higher than the cost of spending time&money on beind on the bleeding 
> edge to do v6-only yet supporting v4 for your existing and future 
> customers still wedded to the older IP protocol?

You are mixing stages of adoption.  The Internet will progress as

1) Early adopters deploy IPv6 while continuing to make most of their
   money off IPv4.  We're already well into this state.

2) Substantially all (> 90%?) of the Internet is dual stacked, or has
   other transition mechanisms in place.

3) IPv4 is removed from the network, leaving only IPv6.

Your comment compares the cost of phase 1 to the cost of phase two,
making the assumption that it's more expensive to be an early adopter
than it is to run dual stack down the road.  On that point, I agree.

My point is once we're in phase #2 the bean counters will look
around and start to ask "can we reduce cost if we remove IPv4".
The answer will be yes.  Initially the answer will be "but our
customers will be upset", and it won't happen, but the bean counters
are persistent, and will keep asking the question over and over.
They will make sure phase 2 lasts no longer than it must.

Which brings us into phase 3.  While engineers may see it as simple
clean up, large networks will see phase 3 has a huge money saving
operation by that point in time.  Once the first major (top 10?)
network removes IPv4 support I expect all the rest to follow within
2 years, tops.  Edge and nitche networks may support it longer, but
it will drop from the Internet core quickly.

The specific original comment was that we would run dual-stacked, that
is in phase 2, for "decades".  I proport there are strong economic
reasons why that is probably not ging to be the case.

       Leo Bicknell - [email protected] - CCIE 3440
        PGP keys at

Attachment: pgp00008.pgp
Description: PGP signature