nanog mailing list archives

Re: Verizon DSL moving to CGN


From: "Rajiv Asati (rajiva)" <rajiva () cisco com>
Date: Mon, 8 Apr 2013 18:45:24 +0000


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




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