Tore is spot on. With MAP, you can use your regular routers, whether it is the Encap mode or Translation mode. One can decide between Encap mode and Translation mode of MAP per his/her environment/requirements. I do find -T mode preferable since it requires no changes to the transparent caching infrastructure or LI infrastructure or QOS policies (if used between CE and Border routers). One may refer to additional details here - http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6553/white_pap er_c11-558744-00.html#wp9000119 http://www.ciscoknowledgenetwork.com/files/300_11-06-2012-NGN-IPv4-Exhaust- IPv6-Strategy.pdf Cheers, Rajiv -----Original Message----- From: Tore Anderson <tore@fud.no> Date: Monday, April 8, 2013 6:29 AM To: Mikael Abrahamsson <swmike@swm.pp.se> Cc: Rajiv Asati <rajiva@cisco.com>, nanog list <nanog@nanog.org> Subject: Re: Verizon DSL moving to CGN
* 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