mailing list archives
Re: Verizon DSL moving to CGN
From: Owen DeLong <owen () delong com>
Date: Mon, 8 Apr 2013 17:49:35 -0700
On Apr 8, 2013, at 07:58 , joel jaeggli <joelja () bogus com> wrote:
On 4/8/13 7:23 AM, Jack Bates wrote:
On 4/8/2013 7:20 AM, Tore Anderson wrote:
BTW. It is AIUI quite possible with MAP to provision a "whole" IPv4
address or even a prefix to the subscriber, thus also taking away the
need for [srcport-restricted] NAPT44 in the CPE.
The problem is NAPT44 in the CPE isn't enough. We are reaching the point that 1 IPv4 Address per customer won't
accommodate user bases.
That happened a long time ago. I realize the people like to think of wireless providers as different, they really
aren't. A big chuck of our mobile gaming customers come to us via carrier operated nat translators. Some of them now
come to us via ipv6, most do not.
The larger issue I think with MAP is CPE support requirements. There are ISP layouts that use bridging instead of
CPE routers (which was a long term design to support IPv6 without CPE replacements years later). CGN will handle the
IPv4 issues in this setup just fine. Then there are those who have already deployed IPv6 capable CPEs with PPP or
DHCP in a router configuration which does not have MAP support. Given the variety of CPE vendors that end up getting
deployed over a longer period of time, it is easier and more cost effective to deploy CGN than try and replace all
Given US$35/CPE, cost for replacements (not including deployment costs) for 20k users is US$700k. CGN gear suddenly
doesn't seem so costly.
The only way I see it justifiable is if you haven't had IPv6 deployment in mind yet and you are having to replace
every CPE for IPv6 support anyways, you might go with a MAPS/IPv6 aware CPE which the customer pays for if they wish
IPv6 connectivity(or during whatever slow trickle replacement methods you utilize). While waiting for the slow
rollout, CGN would be an interim cost that would be acceptable. I'm not sure there is a reason for MAPS if you've
already deployed CGN, though.
I am sure Verizon did a lot of cost analysis.
There is actually a key difference. In the US, at least, everyone is used to the cellular networks mostly sucking.
They are willing to put up with far more degraded service over wireless than they will tolerate on a wired connection.
You and I and everyone else on this list realize that this is complete BS, but the majority of the general public
tolerates it, so it persists.