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 the CPEs.
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.
Jack
