draft-ietf-v6ops-464xlat-07.txt		draft-ietf-v6ops-464xlat-08.txt
	Internet Engineering Task Force M. Mawatari		Internet Engineering Task Force M. Mawatari
	Internet-Draft Japan Internet Exchange Co.,Ltd.		Internet-Draft Japan Internet Exchange Co.,Ltd.
	Intended status: BCP M. Kawashima		Intended status: BCP M. Kawashima
	Expires: February 21, 2013 NEC AccessTechnica, Ltd.		Expires: March 22, 2013 NEC AccessTechnica, Ltd.
	C. Byrne		C. Byrne
	T-Mobile USA		T-Mobile USA
	August 20, 2012		September 18, 2012
	464XLAT: Combination of Stateful and Stateless Translation		464XLAT: Combination of Stateful and Stateless Translation
	draft-ietf-v6ops-464xlat-07		draft-ietf-v6ops-464xlat-08
	Abstract		Abstract
	This document describes an architecture (464XLAT) for providing		This document describes an architecture (464XLAT) for providing
	limited IPv4 connectivity across an IPv6-only network by combining		limited IPv4 connectivity across an IPv6-only network by combining
	existing and well-known stateful protocol translation RFC 6146 in the		existing and well-known stateful protocol translation RFC 6146 in the
	core and stateless protocol translation RFC 6145 at the edge. 464XLAT		core and stateless protocol translation RFC 6145 at the edge. 464XLAT
	is a simple and scalable technique to quickly deploy limited IPv4		is a simple and scalable technique to quickly deploy limited IPv4
	access service to IPv6-only edge networks without encapsulation.		access service to IPv6-only edge networks without encapsulation.
	skipping to change at page 1, line 38		skipping to change at page 1, line 38
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on February 21, 2013.		This Internet-Draft will expire on March 22, 2013.
	Copyright Notice		Copyright Notice
	Copyright (c) 2012 IETF Trust and the persons identified as the		Copyright (c) 2012 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 2, line 14		skipping to change at page 2, line 14
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. BCP Scenario . . . . . . . . . . . . . . . . . . . . . . . . . 3		2. BCP Scenario . . . . . . . . . . . . . . . . . . . . . . . . . 3
	3. Requirements Language . . . . . . . . . . . . . . . . . . . . 3		3. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
	4. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4		4. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
	5. Motivation and Uniqueness of 464XLAT . . . . . . . . . . . . . 4		5. Motivation and Uniqueness of 464XLAT . . . . . . . . . . . . . 4
	6. Network Architecture . . . . . . . . . . . . . . . . . . . . . 4		6. Network Architecture . . . . . . . . . . . . . . . . . . . . . 4
	6.1. Wireline Network Architecture . . . . . . . . . . . . . . 5		6.1. Wireline Network Architecture . . . . . . . . . . . . . . 4
	6.2. Wireless 3GPP Network Architecture . . . . . . . . . . . . 6		6.2. Wireless 3GPP Network Architecture . . . . . . . . . . . . 5
	7. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 7		7. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 6
	7.1. Wireline Network Applicability . . . . . . . . . . . . . . 7		7.1. Wireline Network Applicability . . . . . . . . . . . . . . 6
	7.2. Wireless 3GPP Network Applicability . . . . . . . . . . . 7		7.2. Wireless 3GPP Network Applicability . . . . . . . . . . . 7
	8. Implementation Considerations . . . . . . . . . . . . . . . . 7		8. Implementation Considerations . . . . . . . . . . . . . . . . 7
	8.1. IPv6 Address Format . . . . . . . . . . . . . . . . . . . 8		8.1. IPv6 Address Format . . . . . . . . . . . . . . . . . . . 7
	8.2. IPv4/IPv6 Address Translation Chart . . . . . . . . . . . 8		8.2. IPv4/IPv6 Address Translation Chart . . . . . . . . . . . 7
	8.2.1. Case of enabling only stateless XLATE on CLAT . . . . 8		8.3. IPv6 Prefix Handling . . . . . . . . . . . . . . . . . . . 9
	8.2.2. Case of enabling NAT44 and stateless XLATE on CLAT . . 10		8.4. DNS Proxy Implementation . . . . . . . . . . . . . . . . . 9
	8.3. IPv6 Prefix Handling . . . . . . . . . . . . . . . . . . . 12		8.5. CLAT in a Gateway . . . . . . . . . . . . . . . . . . . . 9
	8.3.1. Case of enabling only stateless XLATE on CLAT . . . . 12		8.6. CLAT to CLAT communications . . . . . . . . . . . . . . . 9
	8.3.2. Case of enabling NAT44 and stateless XLATE on CLAT . . 12		9. Deployment Considerations . . . . . . . . . . . . . . . . . . 9
	8.4. DNS Proxy Implementation . . . . . . . . . . . . . . . . . 12		9.1. Traffic Engineering . . . . . . . . . . . . . . . . . . . 10
	8.5. CLAT in a Gateway . . . . . . . . . . . . . . . . . . . . 13		9.2. Traffic Treatment Scenarios . . . . . . . . . . . . . . . 10
	8.6. CLAT to CLAT communications . . . . . . . . . . . . . . . 13		10. Security Considerations . . . . . . . . . . . . . . . . . . . 11
	9. Deployment Considerations . . . . . . . . . . . . . . . . . . 13		11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
	9.1. Traffic Engineering . . . . . . . . . . . . . . . . . . . 13		12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11
	9.2. Traffic Treatment Scenarios . . . . . . . . . . . . . . . 14		13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
	10. Security Considerations . . . . . . . . . . . . . . . . . . . 14		13.1. Normative References . . . . . . . . . . . . . . . . . . . 11
	11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14		13.2. Informative References . . . . . . . . . . . . . . . . . . 12
	12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15		Appendix A. Examples of IPv4/IPv6 Address Translation . . . . . . 12
	13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
	13.1. Normative References . . . . . . . . . . . . . . . . . . . 15
	13.2. Informative References . . . . . . . . . . . . . . . . . . 15
	Appendix A. Examples of IPv4/IPv6 Address Translation . . . . . . 16
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
	1. Introduction		1. Introduction
	With the exhaustion of the unallocated IPv4 address pools, it will be		With the exhaustion of the unallocated IPv4 address pools, it will be
	difficult for many networks to assign IPv4 addresses to end users.		difficult for many networks to assign IPv4 addresses to end users.
	This document describes an IPv4 over IPv6 solution as one of the		This document describes an IPv4 over IPv6 solution as one of the
	techniques for IPv4 service extension and encouragement of IPv6		techniques for IPv4 service extension and encouragement of IPv6
	deployment. 464XLAT is not a one-for-one replacement of full IPv4		deployment. 464XLAT is not a one-for-one replacement of full IPv4
	functionality. The 464XLAT architecture only supports IPv4 in the		functionality. The 464XLAT architecture only supports IPv4 in the
	skipping to change at page 3, line 31		skipping to change at page 3, line 31
	require DNS64 [RFC6147] since an IPv4 host may simply send IPv4		require DNS64 [RFC6147] since an IPv4 host may simply send IPv4
	packets, including packets to an IPv4 DNS server, which will be		packets, including packets to an IPv4 DNS server, which will be
	translated on the customer side translator(CLAT) to IPv6 and back to		translated on the customer side translator(CLAT) to IPv6 and back to
	IPv4 on the provider side translator(PLAT). 464XLAT networks may use		IPv4 on the provider side translator(PLAT). 464XLAT networks may use
	DNS64 [RFC6147] to enable single stateful translation [RFC6146]		DNS64 [RFC6147] to enable single stateful translation [RFC6146]
	instead of 464XLAT double translation where possible. The 464XLAT		instead of 464XLAT double translation where possible. The 464XLAT
	architecture encourages the IPv6 transition by making IPv4 services		architecture encourages the IPv6 transition by making IPv4 services
	reachable across IPv6-only networks and providing IPv6 and IPv4		reachable across IPv6-only networks and providing IPv6 and IPv4
	connectivity to single-stack IPv4 or IPv6 servers and peers.		connectivity to single-stack IPv4 or IPv6 servers and peers.
	By combining 464XLAT with BIH [RFC6535], it is also possible to
	provide single IPv4 to IPv6 translation service, which will be needed
	in the future case of IPv6-only servers and peers to be reached from
	IPv4-only hosts across IPv6-only networks.
	2. BCP Scenario		2. BCP Scenario
	This BCP only applies when the following two criteria are present:		This BCP only applies when the following two criteria are present:
	1. There is an IPv6-only network that uses stateful translation		1. There is an IPv6-only network that uses stateful translation
	[RFC6146] as the only mechanism for providing IPv4 access.		[RFC6146] as the only mechanism for providing IPv4 access.
	2. There are IPv4-only applications or hosts that must communicate		2. There are IPv4-only applications or hosts that must communicate
	across the IPv6-only network to reach the IPv4 Internet.		across the IPv6-only network to reach the IPv4 Internet.
	skipping to change at page 4, line 17		skipping to change at page 4, line 14
	PLAT: PLAT is Provider side translator(XLAT) that complies with		PLAT: PLAT is Provider side translator(XLAT) that complies with
	[RFC6146]. It translates N:1 global IPv6 addresses to global		[RFC6146]. It translates N:1 global IPv6 addresses to global
	IPv4 addresses, and vice versa.		IPv4 addresses, and vice versa.
	CLAT: CLAT is Customer side translator(XLAT) that complies with		CLAT: CLAT is Customer side translator(XLAT) that complies with
	[RFC6145]. It algorithmically translates 1:1 private IPv4		[RFC6145]. It algorithmically translates 1:1 private IPv4
	addresses to global IPv6 addresses, and vice versa. The CLAT		addresses to global IPv6 addresses, and vice versa. The CLAT
	function is applicable to a router or an end-node such as a		function is applicable to a router or an end-node such as a
	mobile phone. The CLAT SHOULD perform router function to		mobile phone. The CLAT SHOULD perform router function to
	facilitate packets forwarding through the stateless		facilitate packets forwarding through the stateless
	translation even if it is an end-node. In the case where the		translation even if it is an end-node. The CLAT as a common
	access network does not allow for a dedicated IPv6 prefix for		home router or wireless 3GPP router is expected to perform
	translation, a NAT44 SHOULD be used between the router		gateway functions such as DHCP server and DNS proxy for local
	function and the stateless translator function. The CLAT as		clients. The CLAT does not comply with the sentence "Both
	a common home router or wireless 3GPP router is expected to		IPv4-translatable IPv6 addresses and IPv4-converted IPv6
	perform gateway functions such as DHCP server and DNS proxy		addresses SHOULD use the same prefix." that is described on
	for local clients. The CLAT does not comply with the		Section 3.3 in [RFC6052] due to using different IPv6 prefixes
	sentence "Both IPv4-translatable IPv6 addresses and IPv4-		for CLAT-side and PLAT-side IPv4 addresses.
	converted IPv6 addresses SHOULD use the same prefix." that is
	described on Section 3.3 in [RFC6052] due to using different
	IPv6 prefixes for CLAT-side and PLAT-side IPv4 addresses.
	5. Motivation and Uniqueness of 464XLAT		5. Motivation and Uniqueness of 464XLAT
	1. Minimal IPv4 resource requirements, maximum IPv4 efficiency		1. Minimal IPv4 resource requirements, maximum IPv4 efficiency
	through statistical multiplexing.		through statistical multiplexing.
	2. No new protocols required, quick deployment.		2. No new protocols required, quick deployment.
	3. IPv6-only networks are simpler and therefore less expensive to		3. IPv6-only networks are simpler and therefore less expensive to
	operate.		operate.
	6. Network Architecture		6. Network Architecture
	Examples of 464XLAT architectures are show in the figures in the		Examples of 464XLAT architectures are shown in the figures in the
	following sections.		following sections.
	Wireline Network Architecture can fit in the situations that there		Wireline Network Architecture can fit in the situations where there
	are the clients behind the CLAT in the same way regardless of the		are clients behind the CLAT in the same way regardless of the type of
	type of access service, for example FTTH, Cable, or WiFi.		access service, for example FTTH, DOCSIS, or WiFi.
	Wireless 3GPP Network Architecture can fit in the situations that		Wireless 3GPP Network Architecture fits in the situations where a
	client and node that terminate access network is same host in the		client terminates the wireless access network and may act as a router
	same way.		with tethered clients.
	6.1. Wireline Network Architecture		6.1. Wireline Network Architecture
	The private IPv4 host on this diagram can reach global IPv4 hosts via		The private IPv4 host on this diagram can reach global IPv4 hosts via
	translation on both CLAT and PLAT. On the other hand, the IPv6 host		translation on both CLAT and PLAT. On the other hand, the IPv6 host
	can reach other IPv6 hosts on the Internet directly without		can reach other IPv6 hosts on the Internet directly without
	translation. This means that the CPE/CLAT can not only have the		translation. This means that the CPE/CLAT can not only have the
	function of a CLAT but also the function of an IPv6 native router for		function of a CLAT but also the function of an IPv6 native router for
	native IPv6 traffic. The v4p host behind the CLAT on this diagram		native IPv6 traffic. The v4p host behind the CLAT on this diagram
	with the private IPv4 addresses.		has [RFC1918] addresses.
	+------+		+------+
	| v6 |		| v6 |
	| host |		| host |
	+--+---+		+--+---+
	|		|
	.---+---.		.---+---.
	/ \		/ \
	/ IPv6 \		/ IPv6 \
	| Internet |		| Internet |
	skipping to change at page 6, line 8		skipping to change at page 5, line 46
	v6 : Global IPv6		v6 : Global IPv6
	v4p : Private IPv4		v4p : Private IPv4
	v4g : Global IPv4		v4g : Global IPv4
	Figure 1: Wireline Network Topology		Figure 1: Wireline Network Topology
	6.2. Wireless 3GPP Network Architecture		6.2. Wireless 3GPP Network Architecture
	The CLAT function on the User Equipment (UE) provides an [RFC1918]		The CLAT function on the User Equipment (UE) provides an [RFC1918]
	address and IPv4 default route. The applications on the UE can use		address and IPv4 default route to the local node network stack. The
	the private IPv4 address for reaching global IPv4 hosts via		applications on the UE can use the private IPv4 address for reaching
	translation on both CLAT and PLAT. On the other hand, reaching IPv6		global IPv4 hosts via translation on both the CLAT and the PLAT. On
	hosts (including host presented via DNS64 [RFC6147]) does not require		the other hand, reaching IPv6 hosts (including host presented via
	the CLAT function on the UE.		DNS64 [RFC6147]) does not require the CLAT function on the UE.
			Presenting a private IPv4 network for tethering via NAT44 and
			stateless translation on the UE is also an application of the CLAT.
	+------+		+------+
	| v6 |		| v6 |
	| host |		| host |
	+--+---+		+--+---+
	|		|
	.---+---.		.---+---.
	/ \		/ \
	/ IPv6 \		/ IPv6 \
	| Internet |		| Internet |
	skipping to change at page 7, line 19		skipping to change at page 7, line 10
	When an ISP has IPv6 access service and provides 464XLAT, the ISP can		When an ISP has IPv6 access service and provides 464XLAT, the ISP can
	provide outgoing IPv4 service to end users across an IPv6 access		provide outgoing IPv4 service to end users across an IPv6 access
	network. The result is that edge network growth is no longer tightly		network. The result is that edge network growth is no longer tightly
	coupled to the availability of scarce IPv4 addresses.		coupled to the availability of scarce IPv4 addresses.
	If another ISP operates the PLAT, the edge ISP is only required to		If another ISP operates the PLAT, the edge ISP is only required to
	deploy an IPv6 access network. All ISPs do not need IPv4 access		deploy an IPv6 access network. All ISPs do not need IPv4 access
	networks. They can migrate their access network to a simple and		networks. They can migrate their access network to a simple and
	highly scalable IPv6-only environment.		highly scalable IPv6-only environment.
	Incidentally, the effectiveness of 464XLAT was confirmed in the WIDE
	camp Spring 2012. The result is described in
	[I-D.hazeyama-widecamp-ipv6-only-experience].
	7.2. Wireless 3GPP Network Applicability		7.2. Wireless 3GPP Network Applicability
	The vast majority of mobile networks are compliant to Pre-Release 9		At the time of writing, in September 2012, the vast majority of
	3GPP standards. In Pre-Release 9 3GPP networks, GSM and UMTS		mobile networks are compliant to Pre-Release 9 3GPP standards. In
	networks must signal and support both IPv4 and IPv6 Packet Data		Pre-Release 9 3GPP networks, GSM and UMTS networks must signal and
	Protocol (PDP) attachments to access IPv4 and IPv6 network		support both IPv4 and IPv6 Packet Data Protocol (PDP) attachments to
	destinations [RFC6459]. Since there are two PDPs required to support		access IPv4 and IPv6 network destinations [RFC6459]. Since there are
	two address families, this is double the number of PDPs required to		two PDPs required to support two address families, this is double the
	support the status quo of one address family, which is IPv4.		number of PDPs required to support the status quo of one address
			family, which is IPv4.
	For the IPv4 literal or IPv4 socket applications that require IPv4		For the cases of connecting to an IPv4 literal or IPv4 socket that
	connectivity, the CLAT function on the UE provides a private IPv4		require IPv4 connectivity, the CLAT function on the UE provides a
	address and IPv4 default route on the host for the applications to		private IPv4 address and IPv4 default route on the host for the
	reference and bind to. Connections sourced from the IPv4 interface		applications to reference and bind to. Connections sourced from the
	are immediately routed to the CLAT function and passed to the IPv6-		IPv4 interface are immediately routed to the CLAT function and passed
	only mobile network, destined for the PLAT. In summary, the UE has		to the IPv6-only mobile network, destined for the PLAT. In summary,
	the CLAT function that does a stateless translation [RFC6145], but		the UE has the CLAT function that does a stateless translation
	only when required. The mobile network has a PLAT that does stateful		[RFC6145], but only when required by an IPv4-only scenario such as
	translation [RFC6146].		IPv4 literals or IPv4-only sockets. The mobile network has a PLAT
			that does stateful translation [RFC6146].
	464XLAT works with today's existing systems as much as possible.		464XLAT works with today's existing systems as much as possible.
	464XLAT is compatible with existing network based deep packet		464XLAT is compatible with existing network based deep packet
	inspection solutions like 3GPP standardized Policy and Charging		inspection solutions like 3GPP standardized Policy and Charging
	Control (PCC) [TS.23203].		Control (PCC) [TS.23203].
	8. Implementation Considerations		8. Implementation Considerations
	8.1. IPv6 Address Format		8.1. IPv6 Address Format
	The IPv6 address format in 464XLAT is defined in Section 2.2 of		The IPv6 address format in 464XLAT is defined in Section 2.2 of
	[RFC6052].		[RFC6052].
	8.2. IPv4/IPv6 Address Translation Chart		8.2. IPv4/IPv6 Address Translation Chart
	8.2.1. Case of enabling only stateless XLATE on CLAT		This chart offers a explanation about address translation
			architecture using combination of stateful translation at the PLAT
	This case should be used when a prefix delegation mechanism such as		and stateless translation at the CLAT. The client on this chart is
	DHCPv6-PD [RFC3633] is available to assign a dedicated translation		delegated IPv6 prefix from a prefix delegation mechanism such as
	prefix to the CLAT.		DHCPv6-PD [RFC3633], therefore it has a dedicated IPv6 prefix for
			translation.
	Destination IPv4 address		Destination IPv4 address
	+----------------------------+		+----------------------------+
	| Global IPv4 address |		| Global IPv4 address |
	| assigned to IPv4 server |		| assigned to IPv4 server |
	+--------+ +----------------------------+		+--------+ +----------------------------+
	| IPv4 | Source IPv4 address		| IPv4 | Source IPv4 address
	| server | +----------------------------+		| server | +----------------------------+
	+--------+ | Global IPv4 address |		+--------+ | Global IPv4 address |
	^ | assigned to IPv4 PLAT pool |		^ | assigned to IPv4 PLAT pool |
	skipping to change at page 9, line 35		skipping to change at page 8, line 35
	+--------------------------------------------------------------+		+--------------------------------------------------------------+
	Source IPv6 address		Source IPv6 address
	+--------------------------------------------------------------+		+--------------------------------------------------------------+
	| IPv4-Embedded IPv6 address |		| IPv4-Embedded IPv6 address |
	| defined in Section 2.2 of RFC6052 |		| defined in Section 2.2 of RFC6052 |
	+--------------------------------------------------------------+		+--------------------------------------------------------------+
	(IPv6 cloud)		(IPv6 cloud)
	^		^
	|		|
	+--------+		+--------+
	| | In the case the CLAT has a		| CLAT | Stateless XLATE(IPv4:IPv6=1:1)
	| | dedicated IPv6 prefix for
	| CLAT | translation, the CLAT can
	| | perform with only Stateless
	| | XLATE (IPv4:IPv6=1:1).
	+--------+		+--------+
	^ Destination IPv4 address		^ Destination IPv4 address
	| +----------------------------+		| +----------------------------+
	+--------+ | Global IPv4 address |		+--------+ | Global IPv4 address |
	| IPv4 | | assigned to IPv4 server |		| IPv4 | | assigned to IPv4 server |
	| client | +----------------------------+		| client | +----------------------------+
	+--------+ Source IPv4 address		+--------+ Source IPv4 address
	+----------------------------+		+----------------------------+
	| Private IPv4 address |		| Private IPv4 address |
	| assigned to IPv4 client |		| assigned to IPv4 client |
	+----------------------------+		+----------------------------+
	Case of enabling only stateless XLATE on CLAT		Case of enabling only stateless XLATE on CLAT
	8.2.2. Case of enabling NAT44 and stateless XLATE on CLAT
	This case should be used when a prefix delegation mechanism is not
	available to assign a dedicated translation prefix to the CLAT. In
	this case, NAT44 SHOULD be used so that all IPv4 source addresses are
	mapped to a single IPv6 address.
	Destination IPv4 address
	+----------------------------+
	| Global IPv4 address |
	| assigned to IPv4 server |
	+--------+ +----------------------------+
	| IPv4 | Source IPv4 address
	| server | +----------------------------+
	+--------+ | Global IPv4 address |
	^ | assigned to IPv4 PLAT pool |
	| +----------------------------+
	+--------+
	| PLAT | Stateful XLATE(IPv4:IPv6=1:n)
	+--------+
	^
	|
	(IPv6 cloud)
	Destination IPv6 address
	+--------------------------------------------------------------+
	| IPv4-Embedded IPv6 address |
	| defined in Section 2.2 of RFC6052 |
	+--------------------------------------------------------------+
	Source IPv6 address
	+--------------------------------------------------------------+
	| IPv4-Embedded IPv6 address |
	| defined in Section 2.2 of RFC6052 |
	+--------------------------------------------------------------+
	(IPv6 cloud)
	^
	|
	+--------+
	| | In the case the CLAT does not
	| | have a dedicated IPv6 prefix
	| CLAT | for translation, the CLAT can
	| | perform with NAT44 and
	| | Stateless XLATE
	| | (IPv4:IPv6=1:1).
	+--------+
	^ Destination IPv4 address
	| +----------------------------+
	+--------+ | Global IPv4 address |
	| IPv4 | | assigned to IPv4 server |
	| client | +----------------------------+
	+--------+ Source IPv4 address
	+----------------------------+
	| Private IPv4 address |
	| assigned to IPv4 client |
	+----------------------------+
	Case of enabling NAT44 and stateless XLATE on CLAT
	8.3. IPv6 Prefix Handling		8.3. IPv6 Prefix Handling
	8.3.1. Case of enabling only stateless XLATE on CLAT		The CLAT SHOULD acquire a dedicated /64 prefix for the purpose of
			sending and receiving statelessly translated packets.
	From the delegated DHCPv6 [RFC3633] prefix, a /64 is dedicated to
	source and receive IPv6 packets associated with the stateless
	translation [RFC6145].
	The CLAT MAY discover the Pref64::/n of the PLAT via some method such
	as DHCPv6 option, TR-069, DNS APL RR [RFC3123] or
	[I-D.ietf-behave-nat64-discovery-heuristic].
	8.3.2. Case of enabling NAT44 and stateless XLATE on CLAT
	In the case that DHCPv6-PD [RFC3633] is not available, the CLAT may
	not have a dedicated IPv6 prefix for translation. If the CLAT does
	not have a dedicated IPv6 prefix for translation, the CLAT can
	perform NAT44 and stateless translation [RFC6145].
	IPv4 packets from the LAN are NAT44 to the private IPv4 host address
	of the CLAT that is not included in LAN segment of CLAT. Then, the
	CLAT will do a stateless translation [RFC6145] so that the IPv4
	packets from the CLAT IPv4 host address are translated to the CLAT
	WAN IPv6 address as described in [RFC6145].
	If the CLAT cannot perform ND Proxy [RFC4389] due to the restriction		The CLAT MAY discover the PLAT-side translation IPv6 prefix used as a
	of the implementation, the CLAT may use a dedicated IANA assigned		destination of the PLAT via
	EUI-64 ID for creating a translated IPv6 address to be used in		[I-D.ietf-behave-nat64-discovery-heuristic]. In the future some
	stateless translation [RFC6145]. This will allow the CLAT to avoid		other mechanisms, such as a new DHCPv6 option, will possibly be
	possible IPv6 address duplication issues between an IPv6 address for		defined.
	stateless translation [RFC6145] in the CLAT and an IPv6 address
	assigned to native IPv6 nodes behind the CLAT. This document
	describes an example for this case in Example 2. of the Appendix A.
	The CLAT MAY discover the Pref64::/n of the PLAT via some method such		When a dedicated /64 prefix is not available from DHCPv6-PD
	as TR-069, DNS APL RR [RFC3123] or		[RFC3633], the CLAT MAY perform NAT44 for all IPv4 LAN packets so
	[I-D.ietf-behave-nat64-discovery-heuristic].		that all the LAN originated IPv4 packets appear from a single IPv4
			address and are then statelessly translated to one IPv6 address that
			is claimed by the CLAT via NDP and defended with DAD.
	8.4. DNS Proxy Implementation		8.4. DNS Proxy Implementation
	The CLAT SHOULD implement a DNS proxy as defined in [RFC5625]. The		The CLAT SHOULD implement a DNS proxy as defined in [RFC5625]. The
	case of an IPv4-only node behind the CLAT querying an IPv4 DNS server		case of an IPv4-only node behind the CLAT querying an IPv4 DNS server
	is undesirable since it requires both stateful and stateless		is undesirable since it requires both stateful and stateless
	translation for each DNS lookup. The CLAT SHOULD set itself as the		translation for each DNS lookup. The CLAT SHOULD set itself as the
	DNS server via DHCP or other means and proxy DNS queries for IPv4 and		DNS server via DHCP or other means and proxy DNS queries for IPv4 and
	IPv6 LAN clients. Using the CLAT enabled home router or UE as a DNS		IPv6 LAN clients. Using the CLAT enabled home router or UE as a DNS
	proxy is a normal consumer gateway function and simplifies the		proxy is a normal consumer gateway function and simplifies the
	skipping to change at page 14, line 7		skipping to change at page 10, line 28
	2. If the ISP for end users can assign an IPv6 prefix greater than		2. If the ISP for end users can assign an IPv6 prefix greater than
	/64 to each subscriber, this 464XLAT architecture can separate		/64 to each subscriber, this 464XLAT architecture can separate
	IPv6 prefix for native IPv6 packets and the XLAT prefixes for		IPv6 prefix for native IPv6 packets and the XLAT prefixes for
	IPv4/IPv6 translation packets. Accordingly, it can identify the		IPv4/IPv6 translation packets. Accordingly, it can identify the
	type of packets ("native IPv6 packets" and "IPv4/IPv6 translation		type of packets ("native IPv6 packets" and "IPv4/IPv6 translation
	packets"), and implement traffic engineering based on the IPv6		packets"), and implement traffic engineering based on the IPv6
	prefix.		prefix.
	9.2. Traffic Treatment Scenarios		9.2. Traffic Treatment Scenarios
	This 464XLAT architecture has capabilities. One is a IPv4 -> IPv6 ->		The below table outlines how different permutations of connectivity
	IPv4 translation for sharing global IPv4 addresses as a basic		are treated in the 464XLAT architecture.
	function, another, if combined with BIH [RFC6535], is a IPv4 -> IPv6
	translation for reaching IPv6-only servers from IPv4-only clients		NOTE: 464XLAT double translation treatment will be stateless when a
	that can not support IPv6. IPv4-only clients must be support through		dedicated /64 is available for translation on the CLAT. Otherwise,
	the long period of global transition to IPv6.		the CLAT will have both stateful and stateless since it requires
			NAT44 from the LAN to a single IPv4 address and then stateless
			translation to a single IPv6 address.
	+--------+-------------+-----------------------+-------------+		+--------+-------------+-----------------------+-------------+
	| Server | Application | Traffic Treatment | Location of |		| Server | Application | Traffic Treatment | Location of |
	| | and Host | | Translation |		| | and Host | | Translation |
	+--------+-------------+-----------------------+-------------+		+--------+-------------+-----------------------+-------------+
	| IPv6 | IPv6 | End-to-end IPv6 | None |		| IPv6 | IPv6 | End-to-end IPv6 | None |
	+--------+-------------+-----------------------+-------------+		+--------+-------------+-----------------------+-------------+
	| IPv4 | IPv6 | Stateful Translation | PLAT |		| IPv4 | IPv6 | Stateful Translation | PLAT |
	+--------+-------------+-----------------------+-------------+		+--------+-------------+-----------------------+-------------+
	| IPv4 | IPv4 | 464XLAT | PLAT/CLAT |		| IPv4 | IPv4 | 464XLAT | PLAT/CLAT |
	+--------+-------------+-----------------------+-------------+		+--------+-------------+-----------------------+-------------+
	| IPv6 | IPv4 | BIH | CLAT |
	+--------+-------------+-----------------------+-------------+
	Traffic Treatment Scenarios		Traffic Treatment Scenarios
	The above chart shows most common traffic types and traffic
	treatment.
	10. Security Considerations		10. Security Considerations
	To implement a PLAT, see security considerations presented in Section		To implement a PLAT, see security considerations presented in Section
	5 of [RFC6146].		5 of [RFC6146].
	To implement a CLAT, see security considerations presented in Section		To implement a CLAT, see security considerations presented in Section
	7 of [RFC6145]. The CLAT MAY comply with [RFC6092].		7 of [RFC6145]. The CLAT MAY comply with [RFC6092].
	11. IANA Considerations		11. IANA Considerations
	IANA is requested to reserve a Modified EUI-64 identifier for 464XLAT		This document has no actions for IANA.
	according to section 2.2.2 of [RFC5342]. Its suggested value is 02-
	00-5E-00-00-00-00-00 to 02-00-5E-0F-FF-FF-FF-FF or 02-00-5E-10-00-00-
	00-00 to 02-00-5E-EF-FF-FF-FF-FF, depending on whether it should be
	taken in reserved or available values.
	12. Acknowledgements		12. Acknowledgements
	The authors would like to thank JPIX NOC members, JPIX 464XLAT trial		The authors would like to thank JPIX NOC members, JPIX 464XLAT trial
	service members, Seiichi Kawamura, Dan Drown, Brian Carpenter, Rajiv		service members, Seiichi Kawamura, Dan Drown, Brian Carpenter, Rajiv
	Asati, Washam Fan, Behcet Sarikaya, Jan Zorz, Tatsuya Oishi, Lorenzo		Asati, Washam Fan, Behcet Sarikaya, Jan Zorz, Tatsuya Oishi, Lorenzo
	Colitti, Erik Kline, Ole Troan, Maoke Chen, Gang Chen, Tom Petch,		Colitti, Erik Kline, Ole Troan, Maoke Chen, Gang Chen, Tom Petch,
	Jouni Korhonen, and Bjoern A. Zeeb for their helpful comments.		Jouni Korhonen, Bjoern A. Zeeb, Hemant Singh, Vizdal Ales, Mark ZZZ
	Special acknowledgments go to Remi Despres for his plentiful supports		Smith, Mikael Abrahamsson, Tore Anderson, Teemu Savolainen, Alexandru
	and suggestions, especially about using NAT44 with IANA's EUI-64 ID.		Petrescu, Gert Doering, Victor Kuarsingh, Ray Hunter, James Woodyatt,
	We also would like to thank Fred Baker and Joel Jaeggli for their		and Tom Taylor for their helpful comments. Special acknowledgments
	support.		go to Remi Despres for his plentiful supports and suggestions,
			especially about using NAT44 with IANA's EUI-64 ID. We also would
			like to thank Fred Baker and Joel Jaeggli for their support.
	13. References		13. References
	13.1. Normative References		13.1. Normative References
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119, March 1997.		Requirement Levels", BCP 14, RFC 2119, March 1997.
	[RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X.		[RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X.
	Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052,		Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052,
	October 2010.		October 2010.
	[RFC6144] Baker, F., Li, X., Bao, C., and K. Yin, "Framework for
	IPv4/IPv6 Translation", RFC 6144, April 2011.
	[RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation		[RFC6145] Li, X., Bao, C., and F. Baker, "IP/ICMP Translation
	Algorithm", RFC 6145, April 2011.		Algorithm", RFC 6145, April 2011.
	[RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful		[RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful
	NAT64: Network Address and Protocol Translation from IPv6		NAT64: Network Address and Protocol Translation from IPv6
	Clients to IPv4 Servers", RFC 6146, April 2011.		Clients to IPv4 Servers", RFC 6146, April 2011.
	13.2. Informative References		13.2. Informative References
	[I-D.hazeyama-widecamp-ipv6-only-experience]
	Hazeyama, H., Hiromi, R., Ishihara, T., and O. Nakamura,
	"Experiences from IPv6-Only Networks with Transition
	Technologies in the WIDE Camp Spring 2012",
	draft-hazeyama-widecamp-ipv6-only-experience-01 (work in
	progress), March 2012.
	[I-D.ietf-behave-nat64-discovery-heuristic]		[I-D.ietf-behave-nat64-discovery-heuristic]
	Savolainen, T., Korhonen, J., and D. Wing, "Discovery of		Savolainen, T., Korhonen, J., and D. Wing, "Discovery of
	IPv6 Prefix Used for IPv6 Address Synthesis",		IPv6 Prefix Used for IPv6 Address Synthesis",
	draft-ietf-behave-nat64-discovery-heuristic-11 (work in		draft-ietf-behave-nat64-discovery-heuristic-11 (work in
	progress), July 2012.		progress), July 2012.
	[RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and		[RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and
	E. Lear, "Address Allocation for Private Internets",		E. Lear, "Address Allocation for Private Internets",
	BCP 5, RFC 1918, February 1996.		BCP 5, RFC 1918, February 1996.
	[RFC3123] Koch, P., "A DNS RR Type for Lists of Address Prefixes
	(APL RR)", RFC 3123, June 2001.
	[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic		[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic
	Host Configuration Protocol (DHCP) version 6", RFC 3633,		Host Configuration Protocol (DHCP) version 6", RFC 3633,
	December 2003.		December 2003.
	[RFC4389] Thaler, D., Talwar, M., and C. Patel, "Neighbor Discovery
	Proxies (ND Proxy)", RFC 4389, April 2006.
	[RFC5342] Eastlake, D., "IANA Considerations and IETF Protocol Usage
	for IEEE 802 Parameters", BCP 141, RFC 5342,
	September 2008.
	[RFC5625] Bellis, R., "DNS Proxy Implementation Guidelines",		[RFC5625] Bellis, R., "DNS Proxy Implementation Guidelines",
	BCP 152, RFC 5625, August 2009.		BCP 152, RFC 5625, August 2009.
	[RFC6092] Woodyatt, J., "Recommended Simple Security Capabilities in		[RFC6092] Woodyatt, J., "Recommended Simple Security Capabilities in
	Customer Premises Equipment (CPE) for Providing		Customer Premises Equipment (CPE) for Providing
	Residential IPv6 Internet Service", RFC 6092,		Residential IPv6 Internet Service", RFC 6092,
	January 2011.		January 2011.
	[RFC6147] Bagnulo, M., Sullivan, A., Matthews, P., and I. van		[RFC6147] Bagnulo, M., Sullivan, A., Matthews, P., and I. van
	Beijnum, "DNS64: DNS Extensions for Network Address		Beijnum, "DNS64: DNS Extensions for Network Address
	Translation from IPv6 Clients to IPv4 Servers", RFC 6147,		Translation from IPv6 Clients to IPv4 Servers", RFC 6147,
	April 2011.		April 2011.
	[RFC6459] Korhonen, J., Soininen, J., Patil, B., Savolainen, T.,		[RFC6459] Korhonen, J., Soininen, J., Patil, B., Savolainen, T.,
	Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation		Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation
	Partnership Project (3GPP) Evolved Packet System (EPS)",		Partnership Project (3GPP) Evolved Packet System (EPS)",
	RFC 6459, January 2012.		RFC 6459, January 2012.
	[RFC6535] Huang, B., Deng, H., and T. Savolainen, "Dual-Stack Hosts
	Using "Bump-in-the-Host" (BIH)", RFC 6535, February 2012.
	[TS.23203] 3GPP, "Policy and charging control architecture", 3GPP		[TS.23203] 3GPP, "Policy and charging control architecture", 3GPP
	TS 23.203 10.7.0, June 2012.		TS 23.203 10.7.0, June 2012.
	Appendix A. Examples of IPv4/IPv6 Address Translation		Appendix A. Examples of IPv4/IPv6 Address Translation
	The following are examples of IPv4/IPv6 Address Translation on the		The following is a example of IPv4/IPv6 Address Translation on the
	464XLAT architecture.		464XLAT architecture.
	Example 1. (Case of enabling only stateless XLATE on CLAT)
	In the case that an IPv6 prefix greater than /64 is assigned to an		In the case that an IPv6 prefix greater than /64 is assigned to an
	end user by such as DHCPv6-PD [RFC3633], only the Stateless XLATE		end user by such as DHCPv6-PD [RFC3633], the CLAT can use a dedicated
	functionality should be enabled on the CLAT as the CLAT can use a		/64 from the assigned IPv6 prefix.
	dedicated /64 from the assigned IPv6 prefix.
	Host & configuration value		Host & configuration value
	+------------------------------+		+------------------------------+
	| IPv4 server |		| IPv4 server |
	| [198.51.100.1] | IP packet header		| [198.51.100.1] | IP packet header
	+------------------------------+ +--------------------------------+		+------------------------------+ +--------------------------------+
	^ | Destination IP address |		^ | Destination IP address |
	| | [198.51.100.1] |		| | [198.51.100.1] |
	| | Source IP address |		| | Source IP address |
	| | [192.0.2.1] |		| | [192.0.2.1] |
	skipping to change at page 18, line 4		skipping to change at page 14, line 4
	+------------------------------+ +--------------------------------+		+------------------------------+ +--------------------------------+
	^ | Destination IP address |		^ | Destination IP address |
	| | [198.51.100.1] |		| | [198.51.100.1] |
	| | Source IP address |		| | Source IP address |
	| | [192.168.1.2] |		| | [192.168.1.2] |
	+------------------------------+ +--------------------------------+		+------------------------------+ +--------------------------------+
	| IPv4 client |		| IPv4 client |
	| [192.168.1.2/24] |		| [192.168.1.2/24] |
	+------------------------------+		+------------------------------+
	Delegated IPv6 prefix for client: 2001:db8:aaaa::/56		Delegated IPv6 prefix for client: 2001:db8:aaaa::/56
	Example 2. (Case of enabling NAT44 and stateless XLATE on CLAT)
	In the case that IPv6 prefix /64 is assigned to end users, the
	function of NAT44 and Stateless XLATE should be enabled on CLAT.
	Because the CLAT does not have dedicated IPv6 prefix for translation.
	Host & configuration value
	+-------------------------------+
	| IPv4 server |
	| [198.51.100.1] | IP packet header
	+-------------------------------+ +-------------------------------+
	^ | Destination IP address |
	| | [198.51.100.1] |
	| | Source IP address |
	| | [192.0.2.1] |
	+-------------------------------+ +-------------------------------+
	| PLAT | ^
	| IPv4 pool address | |
	| [192.0.2.1 - 192.0.2.100] | |
	| PLAT-side XLATE IPv6 prefix | |
	| [2001:db8:1234::/96] | |
	+-------------------------------+ +-------------------------------+
	^ | Destination IP address |
	| | [2001:db8:1234::198.51.100.1] |
	| | Source IP address |
	| | [2001:db8:aaaa:0:200:5e10::] |
	+-------------------------------+ +-------------------------------+
	| CLAT Stateless XLATE function | ^
	| - - - - - - - - - - - - - - - | |
	| PLAT-side XLATE IPv6 prefix | |
	| [2001:db8:1234::/96] | |
	| CLAT-side XLATE IPv6 prefix | |
	| [2001:db8:aaaa::/64] | |
	| CLAT-side XLATE IPv6 EUI-64 ID| |
	| [02-00-5E-10-00-00-00-00] | |
	+ - - - - - - - - - - - - - - - + +-------------------------------+
	| ^ | | Destination IP address |
	| | | | [198.51.100.1] |
	| | | | Source IP address |
	| | | | [10.255.255.1] |
	+ - - - - - - - - - - - - - - - + +-------------------------------+
	| CLAT NAT44 function | ^
	| - - - - - - - - - - - - - - - | |
	| NAT44 NATed address | |
	| [10.255.255.1/32] | |
	+-------------------------------+ +-------------------------------+
	^ | Destination IP address |
	| | [198.51.100.1] |
	| | Source IP address |
	| | [192.168.1.2] |
	+-------------------------------+ +-------------------------------+
	| IPv4 client |
	| [192.168.1.2/24] |
	+-------------------------------+
	Delegated IPv6 prefix for client: 2001:db8:aaaa::/64
	Authors' Addresses		Authors' Addresses
	Masataka Mawatari		Masataka Mawatari
	Japan Internet Exchange Co.,Ltd.		Japan Internet Exchange Co.,Ltd.
	KDDI Otemachi Building 19F, 1-8-1 Otemachi,		KDDI Otemachi Building 19F, 1-8-1 Otemachi,
	Chiyoda-ku, Tokyo 100-0004		Chiyoda-ku, Tokyo 100-0004
	JAPAN		JAPAN
	Phone: +81 3 3243 9579		Phone: +81 3 3243 9579
End of changes. 38 change blocks.
	284 lines changed or deleted		107 lines changed or added
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