Re: Verizon DSL moving to CGN

[Tore Anderson <tore () fud no>]

* Mikael Abrahamsson

> On Mon, 8 Apr 2013, Rajiv Asati (rajiva) wrote:
>
> > MAP is all about stateless (NAT64 of Encapsulation) and IPv6 enabled
> > access. MAP makes much more sense in any SP network having its
> > internet customers do IPv4 address sharing and embrace IPv6.
>
> It's still NAT.

AIUI, the standards-track flavour of MAP, MAP-E, is *not* NAT - it is
tunneling, pure encap/decap plus a clever way to calculate the outer
IPv6 src/dst addresses from the inner IPv4 addresses and ports. The
inner IPv4 packets are not modified by the centralised MAP tunneling
routers, so there is no "Network Address Translation" being performed.

The tunnel endpoint will 99.99% of cases be a CPE with a NAPT44
component though, so there is some NAT involved in the overall solution,
but it's pretty much the same as what we have in today's CPEs/HGWs. The
only significant difference is that a MAP CPE must be prepared to not
being able to use all the 65536 source ports.

Tore