Why do we still need IPv4 when we are migrating to IPv6...

Anfinsen, Ragnar Ragnar.Anfinsen at altibox.no
Fri Feb 13 14:43:53 CET 2015


In an ideal world, all your statements are true, and for us who has been 
roaming the IPv6 forums and meetings the last year knows all this. 
However, the business side does not see it the same way we do, and that is 
something we all have to deal with and why we are moving so slowly.

Reducing the price of the service is not an option for the sales people, 
unless there are other benefits, and right now there are none. Spending 
for example $650K on IP addresses is far cheaper than reducing the price 
by 20% in addition to investing in the technology to enable MAP, lw4o6 or 
CGN. So unfortunately, we can put the ideology aside and concentrate on 
deploying IPv6 while keeping IPv4 as good as possible. When we finally 
meet the magic threshold, we can start discussing which technology is best 
for keeping the legacy IPv4 available.

I might have misunderstood you, but I think we have totally different 
perspectives when we look at the problem, thus I agree in the ideology, it 
doesn't work like that in the real world.

My goal with my question was to find sensible arguments for keeping IPv4 
as a native service for now, since the cost/benefit does not add up yet. 
However, in the future it might, but I think we are not there yet for the 
next couple of years.


On 13.02.15, 13.38, "Tore Anderson" <tore at fud.no> wrote:

>* Anfinsen, Ragnar
>> On 12.02.15, 22.53, "Tore Anderson" <tore at fud.no> wrote:
>> >There's a non-zero amount of end customers who *do* care about IPv6.
>> >After all, you do have a opt-in service which several thousand of
>> >your customers did actually opt in to - so it would seem to me that
>> >several thousands of your own customers disagree with your statement
>> >above.
>> >
>> >In the same way, you in all likelihood have a non-zero amount of end
>> >customers who do care about having a public IPv4 address all to
>> >themselves. If you did make this an opt-in feature, I'm sure you'd
>> >have many thousands of users opting in to that, too.
>> Compared to the amount of customers, only 1,6% of all our customer
>> having the opt-in option have done so for IPv6. Back in the days when
>> we where doing CGN (yes we have done it for more than 10 years),
>> around 25% of our customers chose to opt-in for a public IPv4
>> address. The main reason for this was that CGN did disrupt their
>> service. Typical examples where OTT SIP services that did not support
>> STUN, customers who wanted to have their own server at home, gamers
>> and more.
>Note that with MAP (maybe also lw4o6, but I'm less familiar with it)
>home servers will work. This is because the customer actually does get
>a public IPv4 address routed to his CPE - the additional restriction is
>that he is limited as to which source ports he can use. So he can't
>expect to be able to set up his SSH server on port 22/tcp, but he will
>be able to set it up on some other port which might well be sufficient
>for his use case.
>Same thing goes for gamers, there the inbound ports are typically
>dynamically assigned with UPnP or something like that, so the CPE is in
>a position to simply assign a port from its assigned range for inbound
>traffic. So for gamers, MAP ought to be pretty much equivalent to
>regular public IPv4 with NAT44 in HGW.
>Anyway, if 25% of your customers have a problem with traditional
>stateful CGN, then you can expect that less than 25% would have a
>problem with MAP. Not only because more application protocols work, but
>also because the mandatory native IPv6 will help avoid problems by
>sidestepping the MAP system and the CPE's NAT44 completely.
>> So I disagree with your statements. 25% of the customer base don't
>> care about addressing, but they do care about connectivity, and as
>> long as there are no perceived differences between IPv4 and IPv6. The
>> 1,6% who have chosen to opt-in for IPv6 are the geeks and the curious
>> people.
>I'm not sure how you can disagree with my statements, since you confirm
>them to be true:
>1) A non-zero amount of your customers (1.6%) care about IPv6
>2) A non-zero amount of your customers (25%) care about public IPv4
>3) The majority of your customers (73.4-75%) do not care about neither
>   IPv6 nor public IPv4
>Right? Group #3 is where you have the largest potential for starting to
>break free of IPv4...
>> >But if you flip it around, there's a non-zero amount of end customers
>> >who do not care about neither having an exclusive public IPv4 address
>> >nor about having IPv6. If I were to venture a guess, that group would
>> >constitute the majority of your customers. Reclaiming those addresses
>> >would likely allow you to postpone your next IPv4 purchase quite a
>> >while, so I'd give that approach serious consideration if I were you.
>> With reference to my statement above, reclaiming is not something you
>> can do without the customer having a choice, and who would like to
>> get their services degraded?
>I've never suggested that you should not give the customer a choice.
>Quite the opposite, I think you *should* give them a choice to have a
>public IPv4 address. That way, you can in good conscience keep your
>«premium» label - just like you do with your by-choice IPv6 offering.
>How to introduce it to existing customers, you might ask? Maybe just
>ask them? Send an SMS saying 20% off your next bill if you give up your
>IPv4 address (and enable IPv6?), pointing out it's not binding and can
>be re-enabled at any time. Or introduce a new invoice item for IPv4
>with a symbolic charge, reducing the base fee accordingly so the total
>stays the same. Inform them that the IPv4 charge can go away if they
>disable the public IPv4 option in the customer portal.
>If ~10k customers take the bait, hey presto, you have reclaimed enough
>addresses to grow by ~40k new subscribers. I can guarantee you that at
>least 1 customer would opt out of public IPv4 btw. ;-)
>> Just to be clear. I am not speaking against IPv6, quite the contrary,
>> as you know I have been a pro IPv6 tech for a long time, but I still
>> have my management team to deal with. And we are not saying "no
>> IPv6", we have rather moved on to "no IPv4?". I think it is to early,
>> and CGN will degrade our service for 25% of our customers, which is a
>> bit to high as of today.
>I think you must have misunderstood me completely.
>I am *not* suggesting that you deploy MAP/CGN for those 25% of your
>customers who would consider this as a service degradation (group #2).
>Quite the opposite, those 25% are precisely the ones who should *not*
>be placed behind MAP/CGN.
>What I *do* suggest that you look into, is MAP/CGN for the 75% of your
>customers who would *not* consider it a service degradation (group #3).
>Those customers are the low-hanging fruits, and considering that
>there's three times as much of them as there is high-hanging fruit
>(group #2) so it's the only logical place to start IMHO.
>But if that's out of the question too, I honestly see no other option
>for you than to keep on buying second-hand IPv4 addresses to fuel your
>growth for the forseeable future.

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