David Miles wrote:
There are certainly other solutions to the issue of
IPv4 runout within
the ISP that do not require CPE change - certainly a plug for some of
the work I have done (and at least one vendor is implementing) is the
L2-Aware NAT: draft-miles-behave-l2nat-00.
In AU/NZ we see a lot of subsidised CPE, and often this CPE is
significantly trimmed in terms of flash, memory and CPU. I have heard
from at least one modem vendor that their lowest cost CPE simply
cannot do DS-Lite faster than 5Mbps. Certainly the counter-argument
goes along the lines of "you need new CPE for IPv6 anyway", so take
with a grain of salt, but the reality is that we are in an IPv4-
dominated world, so continuity of service is critical.
One thing that seems to be missing is a discussion on how an ISP will
roll such services out to market (NAT44, DS-Lite, etc). Only
addressing new customers or new markets seems non-sensical, so it
would appear ISP may be forced to introduce a lower-cost plan to try
and entice customers to use a NAT solution (which DS-Lite certainly is).
The bottom line is that all solutions involve NAPT and will have
application compatibility problems. If an ISP must launch a somewhat
crippled product to market at a lower price-point (but higher cost)
then IPv4-continuity is boiled down into a cost-reduction exercise. I
speculate that an ISP would logically seek the lowest-cost solution,
which would be to avoid CPE change.
My -individual- 2c
The huge problem is all the home customers with ancient second-hand CPE.
I suspect they are also the bulk of customers with 256KB or less
connections. For which some cheap/free CPE flashed to do dualstack at
~5MB is far more speed they they are willing to pay for at present.
A nasty to run, but relatively cheap, exchange program for CPE might be
the way to go there. Old CPE comes in gets flashed and goes out again as
part of the exchange.
The customers willing to pay top dollar for full-speed DSL are also the
bracket most likely to be okay with spending a hundred or so for a new
CPE box. Just to be getting the latest Next Generation Internet. Some
might be willing to slightly downgrade for free.
That just leaves the penny-pincher's amongst the high-speed users. Only
time will tell how big that problem group is.
"Some things only appear as problems until you look at the sideways."
On 15/10/2009, at 7:40 AM, Brian E Carpenter wrote:
About ds-lite. I don't think it's insanity. It's what you do if
(a) you have run out of IPv4 addresses even *within* the ISP
network. That is Comcast's story. (Yes, they are a little bigger
than all NZ ISPs added together.)
(b) your funding agency requires you to run an IPv6-only core. That
is CERNET's story. (Yes, their funding agency runs the largest
country in the world, and seems to think that having fewer addresses
than people is stupid.)
As for possible ISP scenarios, I think there are going to be more.
Watch for an Internet-Draft coming your way very soon.
On 2009-10-14 19:01, Nathan Ward wrote:
I keep getting asked about whether to use
technology X or Y when
deploying an IPv6 network, especially
Copypasta from a post I mate to NANOG just now. Sorry if you've read
this before, but I think it'll be a useful resource for people:
Instead of explaining the options over and over and hoping people can
make sense of the complexities of it, become experts, and make good
informed decisions, I've made a flow chart. Feel free to ask about
details and I can get in to the ranting part, this is really a
Right now it assumes people only provide DSL or other dynamic sort of
It also assumes DS-Lite people are insane, so probably need better
Also the first question is not necessarily about who you are, but
driving the IPv6 'build' - which is why native, 6rd and ds-lite are
appropriate for the customer-driven side. I hope that makes sense.
No talk about ISATAP and stuff for inside the customer network
And before you ask no ISATAP is not appropriate for ISPs, doesn't
- 6RD is used by free.fr. Not widely implemented by anyone yet.
- DS-Lite is something some guys at Comcast and others are talking
about. Not widely implemented by anyone yet.
- The rest you can figure out from wikipedia and stuff.
Please email me with any corrections, complaints, or threats if
DS-Lite fan. I'll always keep old versions in this directory, and the
latest version will always have this filename, so please link to it
instead of copying it, etc. etc.:
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