draft-ietf-dmm-distributed-mobility-anchoring-15.txt		rfc8818.txt
	DMM H. Chan, Ed.		Internet Engineering Task Force (IETF) H. Chan, Ed.
	Internet-Draft X. Wei		Request for Comments: 8818 CIHE
	Intended status: Informational Huawei Technologies		Category: Informational X. Wei
	Expires: September 8, 2020 J. Lee		ISSN: 2070-1721 Huawei Technologies
	Sangmyung University		J. Lee
			Sejong University
	S. Jeon		S. Jeon
	Sungkyunkwan University		Sungkyunkwan University
	CJ. Bernardos, Ed.		CJ. Bernardos, Ed.
	UC3M		UC3M
	March 7, 2020		October 2020
	Distributed Mobility Anchoring		Distributed Mobility Anchoring
	draft-ietf-dmm-distributed-mobility-anchoring-15
	Abstract		Abstract
	This document defines distributed mobility anchoring in terms of the		This document defines distributed mobility anchoring in terms of the
	different configurations and functions to provide IP mobility		different configurations and functions to provide IP mobility
	support. A network may be configured with distributed mobility		support. A network may be configured with distributed mobility
	anchoring functions for both network-based or host-based mobility		anchoring functions for both network-based or host-based mobility
	support according to the needs of mobility support. In a distributed		support, depending on the network's needs. In a distributed mobility
	mobility anchoring environment, multiple anchors are available for		anchoring environment, multiple anchors are available for mid-session
	mid-session switching of an IP prefix anchor. To start a new flow or		switching of an IP prefix anchor. To start a new flow or to handle a
	to handle a flow not requiring IP session continuity as a mobile node		flow not requiring IP session continuity as a mobile node moves to a
	moves to a new network, the flow can be started or re-started using		new network, the flow can be started or restarted using an IP address
	an IP address configured from the new IP prefix anchored to the new		configured from the new IP prefix anchored to the new network. If
	network. If the flow needs to survive the change of network, there		the flow needs to survive the change of network, there are solutions
	are solutions that can be used to enable IP address mobility. This		that can be used to enable IP address mobility. This document
	document describes different anchoring approaches, depending on the		describes different anchoring approaches, depending on the IP
	IP mobility needs, and how this IP address mobility is handled by the		mobility needs, and how this IP address mobility is handled by the
	network.		network.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This document is not an Internet Standards Track specification; it is
	provisions of BCP 78 and BCP 79.		published for informational purposes.
	Internet-Drafts are working documents of the Internet Engineering		This document is a product of the Internet Engineering Task Force
	Task Force (IETF). Note that other groups may also distribute		(IETF). It represents the consensus of the IETF community. It has
	working documents as Internet-Drafts. The list of current Internet-		received public review and has been approved for publication by the
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			approved by the IESG are candidates for any level of Internet
			Standard; see Section 2 of RFC 7841.
	Internet-Drafts are draft documents valid for a maximum of six months		Information about the current status of this document, any errata,
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	time. It is inappropriate to use Internet-Drafts as reference		https://www.rfc-editor.org/info/rfc8818.
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	This Internet-Draft will expire on September 8, 2020.
	Copyright Notice		Copyright Notice
	Copyright (c) 2020 IETF Trust and the persons identified as the		Copyright (c) 2020 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
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	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction
	2. Conventions and Terminology . . . . . . . . . . . . . . . . . 3		2. Conventions and Terminology
	3. Distributed Mobility Anchoring . . . . . . . . . . . . . . . 6		3. Distributed Mobility Anchoring
	3.1. Configurations for Different Networks . . . . . . . . . . 6		3.1. Configurations for Different Networks
	3.1.1. Network-based DMM . . . . . . . . . . . . . . . . . . 7		3.1.1. Network-Based DMM
	3.1.2. Client-based DMM . . . . . . . . . . . . . . . . . . 8		3.1.2. Client-Based DMM
	4. IP Mobility Handling in Distributed Anchoring Environments -		4. IP Mobility Handling in Distributed Anchoring Environments:
	Mobility Support Only When Needed . . . . . . . . . . . . . . 9		Mobility Support Only When Needed
	4.1. Nomadic case (no need of IP mobility): Changing to new IP		4.1. Nomadic Case
	prefix/address . . . . . . . . . . . . . . . . . . . . . 10		4.2. Mobility Case with Traffic Redirection
	4.2. Mobility case, traffic redirection . . . . . . . . . . . 12		4.3. Mobility Case with Anchor Relocation
	4.3. Mobility case, anchor relocation . . . . . . . . . . . . 15		5. Security Considerations
	5. Security Considerations . . . . . . . . . . . . . . . . . . . 16		6. IANA Considerations
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17		7. References
	7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 17		7.1. Normative References
	8. References . . . . . . . . . . . . . . . . . . . . . . . . . 18		7.2. Informative References
	8.1. Normative References . . . . . . . . . . . . . . . . . . 18		Acknowledgements
	8.2. Informative References . . . . . . . . . . . . . . . . . 19		Contributors
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20		Authors' Addresses
	1. Introduction		1. Introduction
	A key requirement in distributed mobility management [RFC7333] is to		A key requirement in distributed mobility management (DMM) [RFC7333]
	enable traffic to avoid traversing a single mobility anchor far from		is to enable traffic to avoid traversing a single mobility anchor far
	an optimal route. This document defines different configurations,		from an optimal route. This document defines different
	functional operations and parameters for distributed mobility		configurations, functional operations, and parameters for distributed
	anchoring and explains how to use them to avoid unnecessarily long		mobility anchoring and explains how to use them to avoid
	routes when a mobile node moves.		unnecessarily long routes when a mobile node moves.
	Companion distributed mobility management documents are already		Other distributed mobility management documents already address
	addressing source address selection [RFC8653], and control-plane		source address selection [RFC8653] and control-plane and data-plane
	data-plane signaling [I-D.ietf-dmm-fpc-cpdp]. A number of		signaling [FPC-DMM-PROTOCOL]. A number of distributed mobility
	distributed mobility solutions have also been proposed, for example,		solutions have also been proposed, for example, in [DMM-DMA],
	in [I-D.seite-dmm-dma], [I-D.ietf-dmm-pmipv6-dlif],		[RFC8885], [DMM-WIFI], [DMM-ENHANCED-ANCHORING], and
	[I-D.sarikaya-dmm-for-wifi], [I-D.yhkim-dmm-enhanced-anchoring], and		[STATELESS-UPLANE-VEPC].
	[I-D.matsushima-stateless-uplane-vepc].
	Distributed mobility anchoring employs multiple anchors in the data		Distributed mobility anchoring employs multiple anchors in the data
	plane. In general, control plane functions may be separated from		plane. In general, control-plane functions may be separated from
	data plane functions and be centralized but may also be co-located		data-plane functions and be centralized but may also be co-located
	with the data plane functions at the distributed anchors. Different		with the data-plane functions at the distributed anchors. Different
	configurations of distributed mobility anchoring are described in		configurations of distributed mobility anchoring are described in
	Section 3.1.		Section 3.1.
	As a Mobile Node (MN) attaches to an access router and establishes a		As a Mobile Node (MN) attaches to an access router and establishes a
	link between them, a /64 IPv6 prefix anchored to the router may be		link between them, a /64 IPv6 prefix anchored to the router may be
	assigned to the link for exclusive use by the MN [RFC6459]. The MN		assigned to the link for exclusive use by the MN [RFC6459]. The MN
	may then configure a global IPv6 address from this prefix and use it		may then configure a global IPv6 address from this prefix and use it
	as the source IP address in a flow to communicate with its		as the source IP address in a flow to communicate with its
	Correspondent Node (CN). When there are multiple mobility anchors		Correspondent Node (CN). When there are multiple mobility anchors
	assigned to the same MN, an address selection for a given flow is		assigned to the same MN, an address selection for a given flow is
	first required before the flow is initiated. Using an anchor in a		first required before the flow is initiated. Using an anchor in an
	MN's network of attachment has the advantage that the packets can		MN's network of attachment has the advantage that the packets can
	simply be forwarded according to the forwarding table. However,		simply be forwarded according to the forwarding table. However,
	after the flow has been initiated, the MN may later move to another		after the flow has been initiated, the MN may later move to another
	network which assigns a new mobility anchor to the MN. Since the new		network that assigns a new mobility anchor to the MN. Since the new
	anchor is located in a different network, the MN's assigned prefix		anchor is located in a different network, the MN's assigned prefix
	does not belong to the network where the MN is currently attached.		does not belong to the network where the MN is currently attached.
	When the MN wants to continue using its assigned prefix to complete		When the MN wants to continue using its assigned prefix to complete
	ongoing data sessions after it has moved to a new network, the		ongoing data sessions after it has moved to a new network, the
	network needs to provide support for the MN's IP address and session		network needs to provide support for the MN's IP address and session
	continuity, since routing packets to the MN through the new network		continuity, since routing packets to the MN through the new network
	deviates from applying default routes. The IP session continuity		deviates from applying default routes. The IP session continuity
	needs of a flow (application) determines how the IP address used by		needs of a flow (application) determine how the IP address used by
	this flow has to be anchored. If the ongoing IP flow can cope with		this flow has to be anchored. If the ongoing IP flow can cope with
	an IP prefix/address change, the flow can be reinitiated with a new		an IP prefix/address change, the flow can be reinitiated with a new
	IP address anchored in the new network. On the other hand, if the		IP address anchored in the new network. On the other hand, if the
	ongoing IP flow cannot cope with such change, mobility support is		ongoing IP flow cannot cope with such change, mobility support is
	needed. A network supporting a mix of flows both requiring and not		needed. A network supporting a mix of flows both requiring and not
	requiring IP mobility support will need to distinguish these flows.		requiring IP mobility support will need to distinguish these flows.
	2. Conventions and Terminology		2. Conventions and Terminology
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and		"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
	"OPTIONAL" in this document are to be interpreted as described in BCP		"OPTIONAL" in this document are to be interpreted as described in
	14 [RFC2119] [RFC8174] when, and only when, they appear in all		BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
	capitals, as shown here.		capitals, as shown here.
	All general mobility-related terms and their acronyms used in this		All general mobility-related terms and their acronyms used in this
	document are to be interpreted as defined in the Mobile IPv6 (MIPv6)		document are to be interpreted as defined in the Mobile IPv6 (MIPv6)
	base specification [RFC6275], the Proxy Mobile IPv6 (PMIPv6)		base specification [RFC6275], the Proxy Mobile IPv6 (PMIPv6)
	specification [RFC5213], the "Mobility Related Terminologies"		specification [RFC5213], the Mobility Terminology document [RFC3753],
	[RFC3753], and the DMM current practices and gap analysis [RFC7429].		and the DMM Current Practices and Gap Analysis document [RFC7429].
	These include terms such as Mobile Node (MN), Correspondent Node		These include terms such as Mobile Node (MN), Correspondent Node
	(CN), Home Agent (HA), Home Address (HoA), Care-of-Address (CoA),		(CN), Home Agent (HA), Home Address (HoA), Care-of-Address (CoA),
	Local Mobility Anchor (LMA), and Mobile Access Gateway (MAG).		Local Mobility Anchor (LMA), and Mobile Access Gateway (MAG).
	In addition, this document uses the following terms and definitions:		In addition, this document uses the following terms and definitions:
	IP session continuity: The ability to maintain an ongoing transport		IP session continuity: The ability to maintain an ongoing transport
	interaction by keeping the same local endpoint IP address		interaction by keeping the same local endpoint IP address
	throughout the lifetime of the IP socket despite the mobile host		throughout the lifetime of the IP socket despite the mobile host
	changing its point of attachment within the IP network topology.		changing its point of attachment within the IP network topology.
	The IP address of the host may change after closing the IP socket		The IP address of the host may change after closing the IP socket
	and before opening a new one, but that does not jeopardize the		and before opening a new one, but that does not jeopardize the
	ability of applications using these IP sockets to work flawlessly.		ability of applications using these IP sockets to work flawlessly.
	Session continuity is essential for mobile hosts to maintain		Session continuity is essential for mobile hosts to maintain
	ongoing flows without any interruption [RFC8653].		ongoing flows without any interruption [RFC8653].
	Higher layer session continuity: The ability to maintain an ongoing		Higher-layer session continuity: The ability to maintain an ongoing
	transport or higher layer (e.g., application) interaction by		transport- or higher-layer (e.g., application) interaction by
	keeping the session indentifiers throughout the lifetime of the		keeping the session identifiers throughout the lifetime of the
	session despite the mobile host changing its point of attachment		session despite the mobile host changing its point of attachment
	within the IP network topology. This can be achieved by using		within the IP network topology. This can be achieved by using
	mechanisms at the transport or higher layers.		mechanisms at the transport or higher layers.
	IP address reachability: The ability to maintain the same IP address		IP address reachability: The ability to maintain the same IP address
	for an extended period of time. The IP address stays the same		for an extended period of time. The IP address stays the same
	across independent sessions, even in the absence of any session.		across independent sessions, even in the absence of any session.
	The IP address may be published in a long-term registry (e.g.,		The IP address may be published in a long-term registry (e.g.,
	DNS) and is made available for serving incoming (e.g., TCP)		DNS) and is made available for serving incoming (e.g., TCP)
	connections. IP address reachability is essential for mobile		connections. IP address reachability is essential for mobile
	hosts to use specific/published IP addresses [RFC8653].		hosts to use specific/published IP addresses [RFC8653].
	IP mobility: Combination of IP address reachability and session		IP mobility: The combination of IP address reachability and session
	continuity.		continuity.
	Home network of a home address: the network that has assigned the		Anchoring (of an IP prefix/address): An IP prefix (i.e., Home
	HoA used as the session identifier by the application running in		Network Prefix (HNP)) or address (i.e., HoA) assigned for use by
	an MN. The MN may be running multiple application sessions, and
	each of these sessions can have a different home network.
	Anchoring (of an IP prefix/address): An IP prefix, i.e., Home
	Network Prefix (HNP), or address, i.e., HoA, assigned for use by
	an MN is topologically anchored to an anchor node when the anchor		an MN is topologically anchored to an anchor node when the anchor
	node is able to advertise a route into the routing infrastructure		node is able to advertise a route into the routing infrastructure
	for the assigned IP prefix. The traffic using the assigned IP		for the assigned IP prefix. The traffic using the assigned IP
	address/prefix must traverse the anchor node. We can refer to the		address/prefix must traverse the anchor node. We can refer to the
	function performed by IP anchor node as anchoring, which is a data		function performed by the IP anchor node as anchoring, which is a
	plane function.		data-plane function.
	Location Management (LM) function: control plane function that keeps		Location Management (LM) function: A control-plane function that
	and manages the network location information of an MN. The		keeps and manages the network location information of an MN. The
	location information may be a binding of the advertised IP		location information may be a binding of the advertised IP
	address/prefix, e.g., HoA or HNP, to the IP routing address of the		address/prefix (e.g., HoA or HNP) to the IP routing address of the
	MN or of a node that can forward packets destined to the MN.		MN or of a node that can forward packets destined to the MN.
	When the MN is a Mobile Router (MR), the location information will		When the MN is a Mobile Router (MR), the location information will
	also include the Mobile Network Prefix (MNP), which is the		also include the Mobile Network Prefix (MNP), which is the
	aggregate IP prefix delegated to the MR to assign IP prefixes for		aggregate IP prefix delegated to the MR to assign IP prefixes for
	use by the Mobile Network Nodes (MNNs) in the mobile network.		use by the Mobile Network Nodes (MNNs) in the mobile network.
	In a client-server protocol model, secure (i.e., authenticated and		In a client-server protocol model, secure (i.e., authenticated and
	authorized) location query and update messages may be exchanged		authorized) location query and update messages may be exchanged
	between a Location Management client (LMc) and a Location		between a Location Management client (LMc) and a Location
	Management server (LMs), where the location information can be		Management server (LMs), where the location information can be
	updated or queried from the LMc. Optionally, there may be a		updated or queried from the LMc. Optionally, there may be a
	Location Management proxy (LMp) between LMc and LMs.		Location Management proxy (LMp) between LMc and LMs.
	With separation of control plane and data plane, the LM function		With separation of control plane and data plane, the LM function
	is in the control plane. It may be a logical function at the		is in the control plane. It may be a logical function at the
	control plane node, control plane anchor, or mobility controller.		control-plane node, control-plane anchor, or mobility controller.
	It may be distributed or centralized.		It may be distributed or centralized.
	Forwarding Management (FM) function: packet interception and		Forwarding Management (FM) function: Packet interception and
	forwarding to/from the IP address/prefix assigned for use by the		forwarding to/from the IP address/prefix assigned for use by the
	MN, based on the internetwork location information, either to the		MN, based on the internetwork location information, either to the
	destination or to some other network element that knows how to		destination or to some other network element that knows how to
	forward the packets to their destination.		forward the packets to their destination.
	This function may be used to achieve traffic indirection. With		This function may be used to achieve traffic indirection. With
	separation of control plane and data plane, the FM function may		separation of control plane and data plane, the FM function may
	split into a FM function in the data plane (FM-DP) and a FM		split into an FM function in the data plane (FM-DP) and an FM
	function in the control plane (FM-CP).		function in the control plane (FM-CP).
	FM-DP may be distributed with distributed mobility management. It		FM-DP may be distributed with distributed mobility management. It
	may be a function in a data plane anchor or data plane node.		may be a function in a data-plane anchor or data-plane node.
	FM-CP may be distributed or centralized. It may be a function in		FM-CP may be distributed or centralized. It may be a function in
	a control plane node, control plane anchor or mobility controller.		a control-plane node, control-plane anchor, or mobility
			controller.
	Home Control-Plane Anchor (Home-CPA or H-CPA): The Home-CPA function		Home Control-Plane Anchor (Home-CPA or H-CPA): The Home-CPA function
	hosts the mobile node (MN)'s mobility session. There can be more		hosts the MN's mobility session. There can be more than one
	than one mobility session for a mobile node and those sessions may		mobility session for a mobile node, and those sessions may be
	be anchored on the same or different Home-CPA's. The home-CPA		anchored on the same or different Home-CPA's. The Home-CPA will
	will interface with the home-DPA for managing the forwarding		interface with the Home-DPA for managing the forwarding state.
	state.
	Home Data Plane Anchor (Home-DPA or H-DPA): The Home-DPA is the		Home Data-Plane Anchor (Home-DPA or H-DPA): The Home-DPA is the
	topological anchor for the MN's IP address/ prefix(es). The Home-		topological anchor for the MN's IP address/prefix(es). The Home-
	DPA is chosen by the Home-CPA on a session- basis. The Home-DPA		DPA is chosen by the Home-CPA on a session basis. The Home-DPA is
	is in the forwarding path for all the mobile node's IP traffic.		in the forwarding path for all the mobile node's IP traffic.
	Access Control Plane Node (Access-CPN or A-CPN): The Access-CPN is		Access Control-Plane Node (Access-CPN or A-CPN): The Access-CPN is
	responsible for interfacing with the mobile node's Home-CPA and		responsible for interfacing with the mobile node's Home-CPA and
	with the Access-DPN. The Access-CPN has a protocol interface to		with the Access-DPN. The Access-CPN has a protocol interface to
	the Home-CPA.		the Home-CPA.
	Access Data Plane Node (Access-DPN or A-DPN): The Access-DPN		Access Data-Plane Node (Access-DPN or A-DPN): The Access-DPN
	function is hosted on the first-hop router where the mobile node		function is hosted on the first-hop router where the mobile node
	is attached. This function is not hosted on a layer-2 bridging		is attached. This function is not hosted on a Layer 2 bridging
	device such as a eNode(B) or Access Point.		device such as an eNode(B) or Access Point.
	3. Distributed Mobility Anchoring		3. Distributed Mobility Anchoring
	3.1. Configurations for Different Networks		3.1. Configurations for Different Networks
	We next describe some configurations with multiple distributed		We next describe some configurations with multiple distributed
	anchors. To cover the widest possible spectrum of scenarios, we		anchors. To cover the widest possible spectrum of scenarios, we
	consider architectures in which the control and data planes are		consider architectures in which the control and data planes are
	separated. We analyze where LM and FM functions -- which are		separated. We analyze where LM and FM functions, which are specific
	specific sub-functions involved in mobility management -- can be		sub-functions involved in mobility management, can be placed when
	placed when looking at the different scenarios with distributed		looking at the different scenarios with distributed anchors.
	anchors.
	3.1.1. Network-based DMM		3.1.1. Network-Based DMM
	Figure 1 shows a general scenario for network-based distributed		Figure 1 shows a general scenario for network-based distributed
	mobility management.		mobility management.
	The main characteristics of a network-based DMM solution are:		The main characteristics of a network-based DMM solution are:
	o There are multiple data plane anchors, each with a FM-DP function.		* There are multiple data-plane anchors, each with an FM-DP
	o The control plane may either be distributed (not shown in the		function.
			* The control plane may either be distributed (not shown in the
	figure) or centralized (as shown in the figure).		figure) or centralized (as shown in the figure).
	o The control plane and the data plane (Control Plane Anchor -- CPA
	-- and Data Plane Anchor -- DPA) may be co-located or not. If the		* The Control-Plane Anchor (CPA) and the Data Plane Anchor (DPA) may
	CPA is co-located with the distributed DPAs, then there are		or may not be co-located. If the CPA is co-located with the
	multiple co-located CPA-DPA instances (not shown in the figure).		distributed DPAs, then there are multiple co-located CPA-DPA
	o An IP prefix/address IP1 (anchored to the DPA with IP address		instances (not shown in the figure).
	IPa1) is assigned for use to a MN. The MN uses this IP1 address
			* An IP prefix/address IP1 (anchored to the DPA with IP address
			IPa1) is assigned for use to an MN. The MN uses this IP1 address
	to communicate with CNs (not shown in the figure).		to communicate with CNs (not shown in the figure).
	o The location management (LM) function may be co-located or split
			* The location management (LM) function may be co-located or split
	(as shown in the figure) into a separate server (LMs) and a client		(as shown in the figure) into a separate server (LMs) and a client
	(LMc). In this case, the LMs may be centralized whereas the LMc		(LMc). In this case, the LMs may be centralized whereas the LMc
	may be distributed or centralized.		may be distributed or centralized.
	____________ Network		____________ Network
	___/ \___________		___/ \___________
	/ +-----+ \___		/ +-----+ \___
	( |LMs | Control \		( |LMs | Control- \
	/ +-.---+ plane \		/ +-.---+ plane \
	/ +--------.---+ functions \		/ +--------.---+ functions \
	( |CPA: . | in the )		( |CPA: . | in the )
	( |FM-CP, LMc | network )		( |FM-CP, LMc | network )
	( +------------+ \		( +------------+ \
	/ . . \		/ . . \
	( . . )		( . . )
	( . . )		( . . )
	( . . \		( . . \
	\ +------------+ +------------+Distributed )		\ +------------+ +------------+Distributed )
	( |DPA(IPa1): | |DPA(IPa2): |DPAs )		( |DPA(IPa1): | |DPA(IPa2): |DPAs )
	( |anchors IP1 | |anchors IP2 | _/		( |anchors IP1 | |anchors IP2 | _/
	\ |FM-DP | |FM-DP | etc. /		\ |FM-DP | |FM-DP | etc. /
	\ +------------+ +------------+ /		\ +------------+ +------------+ /
	\___ Data plane _____/		\___ Data-plane _____/
	\______ functions /		\______ functions /
	\__________________/		\__________________/
	+------------+		+------------+
	|MN(IP1) | Mobile node attached		|MN(IP1) | Mobile node attached
	|flow(IP1,..)| to the network		|flow(IP1,..)| to the network
	+------------+		+------------+
	Figure 1: Network-based DMM configuration		Figure 1: Network-Based DMM Configuration
	3.1.2. Client-based DMM		3.1.2. Client-Based DMM
	Figure 2 shows a general scenario for client-based distributed		Figure 2 shows a general scenario for client-based distributed
	mobility management. In this configuration, the mobile node performs		mobility management. In this configuration, the mobile node performs
	Control Plane Node (CPN) and Data Plane Node (DPN) mobility		Control-Plane Node (CPN) and Data-Plane Node (DPN) mobility
	functions, namely the forwarding management and location management		functions, namely the forwarding management and location management
	(client) roles.		(client) roles.
	+-----+		+-----+
	|LMs |		|LMs |
	+-.---+		+-.---+
	+--------.---+		+--------.---+
	|CPA: . |		|CPA: . |
	|FM-CP, LMp |		|FM-CP, LMp |
	+------------+		+------------+
	skipping to change at page 9, line 28 ¶		skipping to change at line 355 ¶
	|anchors IP1 | |anchors IP2 |		|anchors IP1 | |anchors IP2 |
	|FM-DP | |FM-DP | etc.		|FM-DP | |FM-DP | etc.
	+------------+ +------------+		+------------+ +------------+
	+------------+		+------------+
	|MN(IP1) |Mobile node		|MN(IP1) |Mobile node
	|flow(IP1,..)|using IP1		|flow(IP1,..)|using IP1
	|FM, LMc |anchored to		|FM, LMc |anchored to
	+------------+DPA(IPa1)		+------------+DPA(IPa1)
	Figure 2: Client-based DMM configuration		Figure 2: Client-Based DMM Configuration
	4. IP Mobility Handling in Distributed Anchoring Environments -		4. IP Mobility Handling in Distributed Anchoring Environments: Mobility
	Mobility Support Only When Needed		Support Only When Needed
	IP mobility support may be provided only when needed instead of being		IP mobility support may be provided only when needed instead of being
	provided by default. Three cases can be considered:		provided by default. Three cases can be considered:
	o Nomadic case: no address continuity is required. The IP address		* Nomadic case: No address continuity is required. The IP address
	used by the MN changes after a movement and traffic using the old		used by the MN changes after a movement and traffic using the old
	address is disrupted. If session continuity is required, then it		address is disrupted. If session continuity is required, then it
	needs to be provided by a solution running at L4 or above.		needs to be provided by a solution running at Layer 4 or above.
	o Mobility case, traffic redirection: address continuity is
			* Mobility case with traffic redirection: Address continuity is
	required. When the MN moves, the previous anchor still anchors		required. When the MN moves, the previous anchor still anchors
	the traffic using the old IP address, and forwards it to the new		the traffic using the old IP address and forwards it to the new
	MN's location. The MN obtains a new IP address anchored to the		MN's location. The MN obtains a new IP address anchored to the
	new location, and preferably uses it for new communications,		new location and preferably uses it for new communications
	established while connected at the new location.		established while connected at the new location.
	o Mobility case, anchor relocation: address continuity is required.
	In this case the route followed by the traffic is optimized, by		* Mobility case with anchor relocation: Address continuity is
	using some means for traffic indirection to deviate from default		required. In this case, the route followed by the traffic is
	routes.		optimized by using some means for traffic indirection to deviate
			from default routes.
	A straightforward choice of mobility anchoring is the following: the		A straightforward choice of mobility anchoring is the following: the
	MN's chooses as source IP address for packets belonging to an IP		MN chooses, as a source IP address for packets belonging to an IP
	flow, an address allocated by the network the MN is attached to when		flow, an address allocated by the network the MN is attached to when
	the flow was initiated. As such, traffic belonging to this flow		the flow was initiated. As such, traffic belonging to this flow
	traverses the MN's mobility anchor [I-D.seite-dmm-dma]		traverses the MN's mobility anchor [DMM-DMA] [RFC8885].
	[I-D.ietf-dmm-pmipv6-dlif].
	The IP prefix/address at the MN's side of a flow may be anchored to		The IP prefix/address at the MN's side of a flow may be anchored to
	the Access Router (AR) to which the MN is attached. For example,		the Access Router (AR) to which the MN is attached. For example,
	when a MN attaches to a network (Net1) or moves to a new network		when an MN attaches to a network (Net1) or moves to a new network
	(Net2), an IP prefix from the attached network is assigned to the		(Net2), an IP prefix from the attached network is assigned to the
	MN's interface. In addition to configuring new link-local addresses,		MN's interface. In addition to configuring new link-local addresses,
	the MN configures from this prefix an IP address which is typically a		the MN configures from this prefix an IP address that is typically a
	dynamic IP address (meaning that this address is only used while the		dynamic IP address (meaning that this address is only used while the
	MN is attached to this access router, and therefore the IP address		MN is attached to this access router, so the IP address configured by
	configured by the MN dynamically changes when attaching to a		the MN dynamically changes when attaching to a different access
	different access network). It then uses this IP address when a flow		network). It then uses this IP address when a flow is initiated.
	is initiated. Packets from this flow addressed to the MN are simply		Packets from this flow addressed to the MN are simply forwarded
	forwarded according to the forwarding table.		according to the forwarding table.
	There may be multiple IP prefixes/addresses that an MN can select		There may be multiple IP prefixes/addresses that an MN can select
	when initiating a flow. They may be from the same access network or		when initiating a flow. They may be from the same access network or
	different access networks. The network may advertise these prefixes		different access networks. The network may advertise these prefixes
	with cost options [I-D.mccann-dmm-prefixcost] so that the mobile node		with cost options [PREFIX-COST] so that the mobile node may choose
	may choose the one with the least cost. In addition, the IP		the one with the least cost. In addition, the IP prefixes/addresses
	prefixes/addresses provided by the network may be of different types		provided by the network may be of different types regarding whether
	regarding whether mobility support is supported [RFC8653]. A MN will		mobility support is supported [RFC8653]. An MN will need to choose
	need to choose which IP prefix/address to use for each flow according		which IP prefix/address to use for each flow according to whether or
	to whether it needs IP mobility support or not, using for example the		not it needs IP mobility support, for example, using the mechanisms
	mechanisms described in [RFC8653].		described in [RFC8653].
	4.1. Nomadic case (no need of IP mobility): Changing to new IP prefix/		4.1. Nomadic Case
	address
	When IP mobility support is not needed for a flow, the LM and FM		When IP mobility support is not needed for a flow, the LM and FM
	functions are not utilized so that the configurations in Section 3.1		functions are not utilized so that the configurations in Section 3.1
	are simplified as shown in Figure 3.		are simplified as shown in Figure 3.
	Net1 Net2		Net1 Net2
	+---------------+ +---------------+		+---------------+ +---------------+
	|AR1 | AR is changed |AR2 |		|AR1 | AR is changed |AR2 |
	+---------------+ -------> +---------------+		+---------------+ -------> +---------------+
	skipping to change at page 11, line 21 ¶		skipping to change at line 432 ¶
	|---------------| |---------------|		|---------------| |---------------|
	|DPA(IPa1): | |DPA(IPa2): |		|DPA(IPa1): | |DPA(IPa2): |
	|anchors IP1 | |anchors IP2 |		|anchors IP1 | |anchors IP2 |
	+---------------+ +---------------+		+---------------+ +---------------+
	+...............+ +---------------+		+...............+ +---------------+
	.MN(IP1) . MN moves |MN(IP2) |		.MN(IP1) . MN moves |MN(IP2) |
	.flow(IP1,...) . =======> |flow(IP2,...) |		.flow(IP1,...) . =======> |flow(IP2,...) |
	+...............+ +---------------+		+...............+ +---------------+
	Figure 3: Changing to a new IP address/prefix		Figure 3: Changing to a New IP Address/Prefix
	When there is no need to provide IP mobility to a flow, the flow may		When there is no need to provide IP mobility to a flow, the flow may
	use a new IP address acquired from a new network as the MN moves to		use a new IP address acquired from a new network as the MN moves to
	the new network.		the new network.
	Regardless of whether IP mobility is needed, if the flow has not		Regardless of whether or not IP mobility is needed, if the flow has
	terminated before the MN moves to a new network, the flow may		not terminated before the MN moves to a new network, the flow may
	subsequently restart using the new IP address assigned from the new		subsequently restart using the new IP address assigned from the new
	network.		network.
	When IP session continuity is needed, even if an application flow is		When IP session continuity is needed, even if an application flow is
	ongoing as the MN moves, it may still be desirable for the		ongoing as the MN moves, it may still be desirable for the
	application flow to change to using the new IP prefix configured in		application flow to change to using the new IP prefix configured in
	the new network. The application flow may then be closed at IP level		the new network. The application flow may then be closed at the IP
	and then be restarted using a new IP address configured in the new		level and then be restarted using a new IP address configured in the
	network. Such a change in the IP address used by the application		new network. Such a change in the IP address used by the application
	flow may be enabled using a higher layer mobility support which is		flow may be enabled using a higher-layer mobility support that is not
	not in the scope of this document.		in the scope of this document.
	In Figure 3, a flow initiated while the MN was using the IP prefix		In Figure 3, a flow initiated while the MN was using the IP prefix
	IP1 -- anchored to a previous access router AR1 in network Net1 --		IP1, anchored to a previous access router AR1 in network Net1, has
	has terminated before the MN moves to a new network Net2. After		terminated before the MN moves to a new network Net2. After moving
	moving to Net2, the MN uses the new IP prefix IP2 -- anchored to a		to Net2, the MN uses the new IP prefix IP2, anchored to a new access
	new access router AR2 in network Net2 -- to start a new flow.		router AR2 in network Net2, to start a new flow. Packets may then be
	Packets may then be forwarded without requiring IP layer mobility		forwarded without requiring IP-layer mobility support.
	support.
	An example call flow is outlined in Figure 4. A MN attaches to AR1,		An example call flow is outlined in Figure 4. An MN attaches to AR1,
	which sends a router advertisement (RA) including information about		which sends a router advertisement (RA) including information about
	the prefix assigned to MN, from which MN configures an IP address		the prefix assigned to the MN, from which the MN configures an IP
	(IP1). This address is used for new communications, for example with		address (IP1). This address is used for new communications, for
	a correspondent node (CN). If the MN moves to a new network and		example, with a correspondent node (CN). If the MN moves to a new
	attaches to AR2, the process is repeated (MN obtains a new IP		network and attaches to AR2, the process is repeated (the MN obtains
	address, IP2, from AR2). Since the IP address (IP1) configured at		a new IP address, IP2, from AR2). Since the IP address (IP1)
	the previously visited network is not valid at the current attachment		configured at the previously visited network is not valid at the
	point, and any existing flows have to be reestablished using IP2.		current attachment point, any existing flows have to be reestablished
			using IP2.
	Note that in these scenarios, if there is no mobility support		Note that in these scenarios, if there is no mobility support
	provided by L4 or above, application traffic would stop.		provided by Layer 4 or above, application traffic would stop.
	MN AR1 AR2 CN		MN AR1 AR2 CN
	|MN attaches to AR1: | | |		|MN attaches to AR1: | | |
	|acquires MN-ID and profile | |		|acquires MN-ID and profile | |
	|--RS---------------->| | |		|--RS---------------->| | |
	| | | |		| | | |
	|<----------RA(IP1)---| | |		|<----------RA(IP1)---| | |
	| | | |		| | | |
	Assigned prefix IP1 | | |		Assigned prefix IP1 | | |
	IP1 address configuration | |		IP1 address configuration | |
	skipping to change at page 12, line 38 ¶		skipping to change at line 498 ¶
	|--RS------------------------------>| |		|--RS------------------------------>| |
	| | | |		| | | |
	|<--------------RA(IP2)-------------| |		|<--------------RA(IP2)-------------| |
	| | | |		| | | |
	Assigned prefix IP2 | | |		Assigned prefix IP2 | | |
	IP2 address configuration | |		IP2 address configuration | |
	| | | |		| | | |
	|<-new Flow(IP2,IPcn,...)-----------+---------------------------->|		|<-new Flow(IP2,IPcn,...)-----------+---------------------------->|
	| | | |		| | | |
	Figure 4: Re-starting a flow with new IP prefix/address		Figure 4: Restarting a Flow with New IP Prefix/Address
	4.2. Mobility case, traffic redirection		4.2. Mobility Case with Traffic Redirection
	When IP mobility is needed for a flow, the LM and FM functions in		When IP mobility is needed for a flow, the LM and FM functions in
	Section 3.1 are utilized. There are two possible cases: (i) the		Section 3.1 are utilized. There are two possible cases: (i) the
	mobility anchor remains playing that role and forwards traffic to a		mobility anchor remains playing that role and forwards traffic to a
	new locator in the new network, and (ii) the mobility anchor (data		new locator in the new network, and (ii) the mobility anchor (data-
	plane function) is changed but binds the MN's transferred IP address/		plane function) is changed but binds the MN's transferred IP address/
	prefix. The latter enables optimized routes but requires some data		prefix. The latter enables optimized routes but requires some data-
	plane node that enforces traffic indirection. Next, we focus on the		plane node that enforces traffic indirection. We focus on the first
	first case. The second one is addressed in Section 4.3.		case in this section. The second case is addressed in Section 4.3.
	Mobility support can be provided by using mobility management		Mobility support can be provided by using mobility management
	methods, such as the several approaches surveyed in the academic		methods, such as the approaches surveyed in the following academic
	papers ([Paper-Distributed.Mobility],		papers: [IEEE-DISTRIBUTED-MOBILITY], [PMIP-DMA], and
	[Paper-Distributed.Mobility.PMIP] and		[DMM-MOBILE-INTERNET]. After moving, a certain MN's traffic flow may
	[Paper-Distributed.Mobility.Review]). After moving, a certain MN's		continue using the IP prefix from the prior network of attachment.
	traffic flow may continue using the IP prefix from the prior network		Yet, some time later, the application generating this traffic flow
	of attachment. Yet, some time later, the application generating this		may be closed. If the application is started again, the new flow may
	traffic flow may be closed. If the application is started again, the		not need to use the prior network's IP address to avoid having to
	new flow may not need to use the prior network's IP address to avoid		invoke IP mobility support. This may be the case where a dynamic IP
	having to invoke IP mobility support. This may be the case where a		prefix/address, rather than a permanent one, is used. Packets
	dynamic IP prefix/address, rather than a permanent one, is used.		belonging to this flow may then use the new IP prefix (the one
	Packets belonging to this flow may then use the new IP prefix (the		allocated in the network where the flow is being initiated). Routing
	one allocated in the network where the flow is being initiated).		is again kept simpler without employing IP mobility and will remain
	Routing is again kept simpler without employing IP mobility and will		so as long as the MN, which is now in the new network, does not move
	remain so as long as the MN which is now in the new network does not		again to another network.
	move again to another network.
			An example call flow in this case is outlined in Figure 5. In this
			example, the AR1 plays the role of the FM-DP entity and redirects the
			traffic (e.g., using an IP tunnel) to AR2.
	MN AR1 AR2 CN		MN AR1 AR2 CN
	|MN attaches to AR1: | | |		|MN attaches to AR1: | | |
	|acquires MN-ID and profile | |		|acquires MN-ID and profile | |
	|--RS---------------->| | |		|--RS---------------->| | |
	| | | |		| | | |
	|<----------RA(IP1)---| | |		|<----------RA(IP1)---| | |
	| | | |		| | | |
	Assigned prefix IP1 | | |		Assigned prefix IP1 | | |
	IP1 address configuration | |		IP1 address configuration | |
	skipping to change at page 14, line 36 ¶		skipping to change at line 562 ¶
	|<-Flow(IP1,IPcn,...)-------------->+ |		|<-Flow(IP1,IPcn,...)-------------->+ |
	| | | |		| | | |
	Assigned prefix IP2 | | |		Assigned prefix IP2 | | |
	IP2 address configuration | |		IP2 address configuration | |
	| | | |		| | | |
	Flow(IP1,IPcn) terminates | |		Flow(IP1,IPcn) terminates | |
	| | | |		| | | |
	|<-new Flow(IP2,IPcn,...)-----------+---------------------------->|		|<-new Flow(IP2,IPcn,...)-----------+---------------------------->|
	| | | |		| | | |
	Figure 5: A flow continues to use the IP prefix from its home network		Figure 5: Flow Using IP Prefix from Home Network after MN has Moved
	after MN has moved to a new network
	An example call flow in this case is outlined in Figure 5. In this		Another solution could be to place an FM-DP entity closer to the CN
	example, the AR1 plays the role of FM-DP entity and redirects the		network to perform traffic steering to deviate from default routes
	traffic (e.g., using an IP tunnel) to AR2. Another solution could be		(which will bring the packet to AR1 per default routing). The LM and
	to place an FM-DP entity closer to the CN network to perform traffic		FM functions are implemented as shown in Figure 6.
	steering to deviate from default routes (which will bring the packet
	to AR1 per default routing). The LM and FM functions are implemented
	as shown in Figure 6.
	Net1 Net2		Net1 Net2
	+---------------+ +---------------+		+---------------+ +---------------+
	|AR1 | |AR2 |		|AR1 | |AR2 |
	+---------------+ +---------------+		+---------------+ +---------------+
	|CPA: | |CPA: |		|CPA: | |CPA: |
	| | |LM:IP1 at IPa1 |		| | |LM:IP1 at IPa1 |
	|---------------| IP1 (anchored to Net1) |---------------|		|---------------| IP1 (anchored to Net1) |---------------|
	|DPA(IPa1): | is redirected to Net2 |DPA(IPa2): |		|DPA(IPa1): | is redirected to Net2 |DPA(IPa2): |
	|anchors IP1 | =======> |anchors IP2 |		|anchors IP1 | =======> |anchors IP2 |
	|FM:IP1 via IPa2| |FM:IP1 via IPa1|		|FM:IP1 via IPa2| |FM:IP1 via IPa1|
	+---------------+ +---------------+		+---------------+ +---------------+
	+...............+ +---------------+		+...............+ +---------------+
	.MN(IP1) . MN moves |MN(IP2,IP1) |		.MN(IP1) . MN moves |MN(IP2,IP1) |
	.flow(IP1,...) . =======> |flow(IP1,...) |		.flow(IP1,...) . =======> |flow(IP1,...) |
	. . |flow(IP2,...) |		. . |flow(IP2,...) |
	+...............+ +---------------+		+...............+ +---------------+
	Figure 6: Anchor redirection		Figure 6: Anchor Redirection
	Multiple instances of DPAs (at access routers), which are providing		Multiple instances of DPAs (at access routers), which are providing
	IP prefixes to the MNs, are needed to provide distributed mobility		IP prefixes to the MNs, are needed to provide distributed mobility
	anchoring in an appropriate configuration such as those described in		anchoring in an appropriate configuration such as those described in
	Figure 1 (Section 3.1.1) for network-based distributed mobility or in		Figure 1 (Section 3.1.1) for network-based distributed mobility or in
	Figure 2 (Section 3.1.2) for client-based distributed mobility.		Figure 2 (Section 3.1.2) for client-based distributed mobility.
	4.3. Mobility case, anchor relocation		4.3. Mobility Case with Anchor Relocation
	We focus next on the case where the mobility anchor (data plane		We focus next on the case where the mobility anchor (data-plane
	function) is changed but binds the MN's transferred IP address/		function) is changed but binds the MN's transferred IP address/
	prefix. This enables optimized routes but requires some data plane		prefix. This enables optimized routes but requires some data-plane
	node that enforces traffic indirection.		node that enforces traffic indirection.
	IP mobility is invoked to enable IP session continuity for an ongoing		IP mobility is invoked to enable IP session continuity for an ongoing
	flow as the MN moves to a new network. The anchoring of the IP		flow as the MN moves to a new network. The anchoring of the IP
	address of the flow is in the home network of the flow (i.e.,		address of the flow is in the home network of the flow (i.e.,
	different from the current network of attachment). A centralized		different from the current network of attachment). A centralized
	mobility management mechanism may employ indirection from the anchor		mobility management mechanism may employ indirection from the anchor
	in the home network to the current network of attachment. Yet it may		in the home network to the current network of attachment. Yet, it
	be difficult to avoid using an unnecessarily long route (when the		may be difficult to avoid using an unnecessarily long route (when the
	route between the MN and the CN via the anchor in the home network is		route between the MN and the CN via the anchor in the home network is
	significantly longer than the direct route between them). An		significantly longer than the direct route between them). An
	alternative is to move the IP prefix/address anchoring to the new		alternative is to move the IP prefix/address anchoring to the new
	network.		network.
	The IP prefix/address anchoring may move without changing the IP		The IP prefix/address anchoring may move without changing the IP
	prefix/address of the flow. The LM function in Figure 1 in		prefix/address of the flow. The LM function in Figure 1 of
	Section 3.1.1 is implemented as shown in Figure 7.		Section 3.1.1 is implemented as shown in Figure 7.
	Net1 Net2		Net1 Net2
	+---------------+ +---------------+		+---------------+ +---------------+
	|AR1 | |AR2 |		|AR1 | |AR2 |
	+---------------+ +---------------+		+---------------+ +---------------+
	|CPA: | |CPA: |		|CPA: | |CPA: |
	|LM:IP1 at IPa1 | |LM:IP1 at IPa2 |		|LM:IP1 at IPa1 | |LM:IP1 at IPa2 |
	| changes to | | |		| changes to | | |
	skipping to change at page 16, line 28 ¶		skipping to change at line 638 ¶
	|---------------| |---------------|		|---------------| |---------------|
	|DPA(IPa1): | IP1 anchoring effectively moved |DPA(IPa2): |		|DPA(IPa1): | IP1 anchoring effectively moved |DPA(IPa2): |
	|anchored IP1 | =======> |anchors IP2,IP1|		|anchored IP1 | =======> |anchors IP2,IP1|
	+---------------+ +---------------+		+---------------+ +---------------+
	+...............+ +---------------+		+...............+ +---------------+
	.MN(IP1) . MN moves |MN(IP2,IP1) |		.MN(IP1) . MN moves |MN(IP2,IP1) |
	.flow(IP1,...) . =======> |flow(IP1,...) |		.flow(IP1,...) . =======> |flow(IP1,...) |
	+...............+ +---------------+		+...............+ +---------------+
	Figure 7: Anchor relocation		Figure 7: Anchor Relocation
	As an MN with an ongoing session moves to a new network, the flow may		As an MN with an ongoing session moves to a new network, the flow may
	preserve IP session continuity by moving the anchoring of the		preserve IP session continuity by moving the anchoring of the
	original IP prefix/address of the flow to the new network.		original IP prefix/address of the flow to the new network.
	One way to accomplish such a move is to use a centralized routing		One way to accomplish such a move is to use a centralized routing
	protocol, but such a solution may present some scalability concerns		protocol, but such a solution may present some scalability concerns
	and its applicability is typically limited to small networks. One		and its applicability is typically limited to small networks. One
	example of this type of solution is described in		example of this type of solution is described in [BGP-ATN-IPS]. When
	[I-D.ietf-rtgwg-atn-bgp]. When a MN associates with an anchor the		an MN associates with an anchor, the anchor injects the MN's prefix
	anchor injects the mobile's prefix into the global routing system.		into the global routing system. If the MN moves to a new anchor, the
	If the MN moves to a new anchor, the old anchor withdraws the /64 and		old anchor withdraws the /64 and the new anchor injects it instead.
	the new anchor injects it instead.
	5. Security Considerations		5. Security Considerations
	As stated in [RFC7333], "a DMM solution MUST support any security		As stated in [RFC7333], "a DMM solution MUST support any security
	protocols and mechanisms needed to secure the network and to make		protocols and mechanisms needed to secure the network and to make
	continuous security improvements". It "MUST NOT introduce new		continuous security improvements". It "MUST NOT introduce new
	security risks".		security risks".
	There are different potential deployment models of a DMM solution.		There are different potential deployment models of a DMM solution.
	The present document has presented 3 different scenarios for		The present document has presented three different scenarios for
	distributed anchoring: (i) nomadic case, (ii) mobility case with		distributed anchoring: (i) nomadic case, (ii) mobility case with
	traffic redirection, and (iii) mobility case with anchor relocation.		traffic redirection, and (iii) mobility case with anchor relocation.
	Each of them has different security requirements, and the actual		Each of these cases has different security requirements, and the
	security mechanisms would depend on the specifics of each solution/		actual security mechanisms depend on the specifics of each solution/
	scenario.		scenario.
	As general rules, for the first distributed anchoring scenario		As general rules, for the first distributed anchoring scenario
	(nomadic case), no additional security consideration is needed, as		(nomadic case), no additional security consideration is needed, as
	this does not involve any additional mechanism at L3. If session		this does not involve any additional mechanism at Layer 3. If
	connectivity is required, the L4 or above solution used to provide it		session connectivity is required, the Layer 4 or above solution used
	MUST also provide the required authentication and security.		to provide it MUST also provide the required authentication and
			security.
	The second and third distributed anchoring scenarios (mobility case)		The second and third distributed anchoring scenarios (mobility case)
	involve mobility signalling among the mobile node and the control and		involve mobility signaling among the mobile node and the control-
	data plane anchors. The control-plane messages exchanged between		plane and data-plane anchors. The control-plane messages exchanged
	these entitites MUST be protected using end-to-end security		between these entities MUST be protected using end-to-end security
	associations with data-integrity and data-origination capabilities.		associations with data-integrity and data-origination capabilities.
	IPsec [RFC8221] ESP in transport mode with mandatory integrity		IPsec [RFC8221] Encapsulating Security Payload (ESP) in transport
	protection SHOULD be used for protecting the signaling messages.		mode with mandatory integrity protection SHOULD be used for
	IKEv2 [RFC8247] SHOULD be used to set up security associations		protecting the signaling messages. Internet Key Exchange Protocol
	between the data and control plane anchors. Note that in scenarios		Version 2 (IKEv2) [RFC8247] SHOULD be used to set up security
	in which traffic indirection mechanisms are used to relocate an		associations between the data-plane and control-plane anchors. Note
	anchor, authentication and authorization mechanisms MUST be used.		that in scenarios in which traffic indirection mechanisms are used to
			relocate an anchor, authentication and authorization mechanisms MUST
			be used.
	Control-plane functionality MUST apply authorization checks to any		Control-plane functionality MUST apply authorization checks to any
	commands or updates that are made by the control-plane protocol.		commands or updates that are made by the control-plane protocol.
	6. IANA Considerations		6. IANA Considerations
	This document presents no IANA considerations.		This document has no IANA actions.
	7. Contributors
	Alexandre Petrescu and Fred Templin had contributed to earlier
	versions of this document regarding distributed anchoring for
	hierarchical network and for network mobility, although these
	extensions were removed to keep the document within reasonable
	length.
	This document has benefited from other work on mobility support in
	SDN network, on providing mobility support only when needed, and on
	mobility support in enterprise network. These works have been
	referenced. While some of these authors have taken the work to
	jointly write this document, others have contributed at least
	indirectly by writing these drafts. The latter include Philippe
	Bertin, Dapeng Liu, Satoru Matushima, Pierrick Seite, Jouni Korhonen,
	and Sri Gundavelli.
	Some terminology has been incorporated for completeness from draft-
	ietf-dmm-deployment-models-04 document.
	Valuable comments have been received from John Kaippallimalil,
	ChunShan Xiong, Dapeng Liu, Fred Templin, Paul Kyzivat, Joseph
	Salowey, Yoshifumi Nishida, Carlos Pignataro, Mirja Kuehlewind, Eric
	Vyncke, Qin Wu, Warren Kumari, Benjamin Kaduk, Roman Danyliw and
	Barry Leiba. Dirk von Hugo, Byju Pularikkal, Pierrick Seite have
	generously provided careful review with helpful corrections and
	suggestions. Marco Liebsch and Lyle Bertz also performed very
	detailed and helpful reviews of this document.
	8. References		7. References
	8.1. Normative References		7.1. 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,		Requirement Levels", BCP 14, RFC 2119,
	DOI 10.17487/RFC2119, March 1997,		DOI 10.17487/RFC2119, March 1997,
	<https://www.rfc-editor.org/info/rfc2119>.		<https://www.rfc-editor.org/info/rfc2119>.
	[RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related		[RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related
	Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004,		Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004,
	<https://www.rfc-editor.org/info/rfc3753>.		<https://www.rfc-editor.org/info/rfc3753>.
	skipping to change at page 19, line 18 ¶		skipping to change at line 745 ¶
	Payload (ESP) and Authentication Header (AH)", RFC 8221,		Payload (ESP) and Authentication Header (AH)", RFC 8221,
	DOI 10.17487/RFC8221, October 2017,		DOI 10.17487/RFC8221, October 2017,
	<https://www.rfc-editor.org/info/rfc8221>.		<https://www.rfc-editor.org/info/rfc8221>.
	[RFC8247] Nir, Y., Kivinen, T., Wouters, P., and D. Migault,		[RFC8247] Nir, Y., Kivinen, T., Wouters, P., and D. Migault,
	"Algorithm Implementation Requirements and Usage Guidance		"Algorithm Implementation Requirements and Usage Guidance
	for the Internet Key Exchange Protocol Version 2 (IKEv2)",		for the Internet Key Exchange Protocol Version 2 (IKEv2)",
	RFC 8247, DOI 10.17487/RFC8247, September 2017,		RFC 8247, DOI 10.17487/RFC8247, September 2017,
	<https://www.rfc-editor.org/info/rfc8247>.		<https://www.rfc-editor.org/info/rfc8247>.
	8.2. Informative References		7.2. Informative References
	[I-D.ietf-dmm-fpc-cpdp]
	Matsushima, S., Bertz, L., Liebsch, M., Gundavelli, S.,
	Moses, D., and C. Perkins, "Protocol for Forwarding Policy
	Configuration (FPC) in DMM", draft-ietf-dmm-fpc-cpdp-12
	(work in progress), June 2018.
	[I-D.ietf-dmm-pmipv6-dlif]
	Bernardos, C., Oliva, A., Giust, F., Zuniga, J., and A.
	Mourad, "Proxy Mobile IPv6 extensions for Distributed
	Mobility Management", draft-ietf-dmm-pmipv6-dlif-05 (work
	in progress), November 2019.
	[I-D.ietf-rtgwg-atn-bgp]		[BGP-ATN-IPS]
	Templin, F., Saccone, G., Dawra, G., Lindem, A., and V.		Templin, F., Saccone, G., Dawra, G., Lindem, A., and V.
	Moreno, "A Simple BGP-based Mobile Routing System for the		Moreno, "A Simple BGP-based Mobile Routing System for the
	Aeronautical Telecommunications Network", draft-ietf-		Aeronautical Telecommunications Network", Work in
	rtgwg-atn-bgp-05 (work in progress), January 2020.		Progress, Internet-Draft, draft-ietf-rtgwg-atn-bgp-06, 30
			June 2020,
			<https://tools.ietf.org/html/draft-ietf-rtgwg-atn-bgp-06>.
	[I-D.matsushima-stateless-uplane-vepc]		[DMM-DMA] Seite, P., Bertin, P., and J. Lee, "Distributed Mobility
	Matsushima, S. and R. Wakikawa, "Stateless user-plane		Anchoring", Work in Progress, Internet-Draft, draft-seite-
	architecture for virtualized EPC (vEPC)", draft-		dmm-dma-07, 6 February 2014,
	matsushima-stateless-uplane-vepc-06 (work in progress),		<https://tools.ietf.org/html/draft-seite-dmm-dma-07>.
	March 2016.
	[I-D.mccann-dmm-prefixcost]		[DMM-ENHANCED-ANCHORING]
	McCann, P. and J. Kaippallimalil, "Communicating Prefix		Kim, Y. and S. Jeon, "Enhanced Mobility Anchoring in
	Cost to Mobile Nodes", draft-mccann-dmm-prefixcost-03		Distributed Mobility Management", Work in Progress,
	(work in progress), April 2016.		Internet-Draft, draft-yhkim-dmm-enhanced-anchoring-05, 8
			July 2016, <https://tools.ietf.org/html/draft-yhkim-dmm-
			enhanced-anchoring-05>.
	[I-D.sarikaya-dmm-for-wifi]		[DMM-MOBILE-INTERNET]
	Sarikaya, B. and L. Li, "Distributed Mobility Management		Chan, H., Yokota, H., Xie, J., Seite, P., and D. Liu,
	Protocol for WiFi Users in Fixed Network", draft-sarikaya-		"Distributed and Dynamic Mobility Management in Mobile
	dmm-for-wifi-05 (work in progress), October 2017.		Internet: Current Approaches and Issues", Journal of
			Communications, Vol. 6, No. 1, February 2011.
	[I-D.seite-dmm-dma]		[DMM-WIFI] Sarikaya, B. and L. Li, "Distributed Mobility Management
	Seite, P., Bertin, P., and J. Lee, "Distributed Mobility		Protocol for WiFi Users in Fixed Network", Work in
	Anchoring", draft-seite-dmm-dma-07 (work in progress),		Progress, Internet-Draft, draft-sarikaya-dmm-for-wifi-05,
	February 2014.		30 October 2017, <https://tools.ietf.org/html/draft-
			sarikaya-dmm-for-wifi-05>.
	[I-D.yhkim-dmm-enhanced-anchoring]		[FPC-DMM-PROTOCOL]
	Kim, Y. and S. Jeon, "Enhanced Mobility Anchoring in		Matsushima, S., Bertz, L., Liebsch, M., Gundavelli, S.,
	Distributed Mobility Management", draft-yhkim-dmm-		Moses, D., and C. Perkins, "Protocol for Forwarding Policy
	enhanced-anchoring-05 (work in progress), July 2016.		Configuration (FPC) in DMM", Work in Progress, Internet-
			Draft, draft-ietf-dmm-fpc-cpdp-14, 22 September 2020,
			<https://tools.ietf.org/html/draft-ietf-dmm-fpc-cpdp-14>.
	[Paper-Distributed.Mobility]		[IEEE-DISTRIBUTED-MOBILITY]
	Lee, J., Bonnin, J., Seite, P., and H. Chan, "Distributed		Lee, J., Bonnin, J., Seite, P., and H. A. Chan,
	IP Mobility Management from the Perspective of the IETF:		"Distributed IP mobility management from the perspective
	Motivations, Requirements, Approaches, Comparison, and		of the IETF: motivations, requirements, approaches,
	Challenges", IEEE Wireless Communications, October 2013.		comparison, and challenges", IEEE Wireless Communications,
			vol. 20, no. 5, pp. 159-168, October 2013.
	[Paper-Distributed.Mobility.PMIP]		[PMIP-DMA] Chan, H., "Proxy mobile IP with distributed mobility
	Chan, H., "Proxy Mobile IP with Distributed Mobility		anchors", IEEE Globecom Workshops Miami, FL, 2010, pp.
	Anchors", Proceedings of GlobeCom Workshop on Seamless		16-20, December 2010.
	Wireless Mobility, December 2010.
	[Paper-Distributed.Mobility.Review]		[PREFIX-COST]
	Chan, H., Yokota, H., Xie, J., Seite, P., and D. Liu,		McCann, P. and J. Kaippallimalil, "Communicating Prefix
	"Distributed and Dynamic Mobility Management in Mobile		Cost to Mobile Nodes", Work in Progress, Internet-Draft,
	Internet: Current Approaches and Issues", February 2011.		draft-mccann-dmm-prefixcost-03, 11 April 2016,
			<https://tools.ietf.org/html/draft-mccann-dmm-prefixcost-
			03>.
	[RFC6459] Korhonen, J., Ed., Soininen, J., Patil, B., Savolainen,		[RFC6459] Korhonen, J., Ed., Soininen, J., Patil, B., Savolainen,
	T., Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation		T., 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, DOI 10.17487/RFC6459, January 2012,		RFC 6459, DOI 10.17487/RFC6459, January 2012,
	<https://www.rfc-editor.org/info/rfc6459>.		<https://www.rfc-editor.org/info/rfc6459>.
	[RFC8653] Yegin, A., Moses, D., and S. Jeon, "On-Demand Mobility		[RFC8653] Yegin, A., Moses, D., and S. Jeon, "On-Demand Mobility
	Management", RFC 8653, DOI 10.17487/RFC8653, October 2019,		Management", RFC 8653, DOI 10.17487/RFC8653, October 2019,
	<https://www.rfc-editor.org/info/rfc8653>.		<https://www.rfc-editor.org/info/rfc8653>.
			[RFC8885] Bernardos, CJ., de la Oliva, A., Giust, F., Zúñiga, JC.,
			and A. Mourad, "Proxy Mobile IPv6 Extensions for
			Distributed Mobility Management", RFC 8885,
			DOI 10.17487/RFC8885, October 2020,
			<https://www.rfc-editor.org/info/rfc8885>.
			[STATELESS-UPLANE-VEPC]
			Matsushima, S. and R. Wakikawa, "Stateless user-plane
			architecture for virtualized EPC (vEPC)", Work in
			Progress, Internet-Draft, draft-matsushima-stateless-
			uplane-vepc-06, 21 March 2016,
			<https://tools.ietf.org/html/draft-matsushima-stateless-
			uplane-vepc-06>.
			Acknowledgements
			The work of Jong-Hyouk Lee was supported by the MSIT (Ministry of
			Science and ICT), Korea, under the ITRC (Information Technology
			Research Center) support program (IITP-2020-2015-0-00403) supervised
			by the IITP (Institute for Information & communications Technology
			Planning & Evaluation).
			Contributors
			Alexandre Petrescu and Fred Templin had contributed to earlier draft
			versions of this document regarding distributed anchoring for
			hierarchical networks and for network mobility, although these
			extensions were removed to keep the document within reasonable
			length.
			This document has benefited from other work on mobility support in
			SDN networks, on providing mobility support only when needed, and on
			mobility support in enterprise networks. These works have been
			referenced. While some of these authors have taken the work to
			jointly write this document, others have contributed at least
			indirectly by writing these works. The latter include Philippe
			Bertin, Dapeng Liu, Satoru Matushima, Pierrick Seite, Jouni Korhonen,
			and Sri Gundavelli.
			For completeness, some terminology from draft-ietf-dmm-deployment-
			models-04 has been incorporated into this document.
			Valuable comments have been received from John Kaippallimalil,
			ChunShan Xiong, Dapeng Liu, Fred Templin, Paul Kyzivat, Joseph
			Salowey, Yoshifumi Nishida, Carlos Pignataro, Mirja Kuehlewind, Eric
			Vyncke, Qin Wu, Warren Kumari, Benjamin Kaduk, Roman Danyliw, and
			Barry Leiba. Dirk von Hugo, Byju Pularikkal, and Pierrick Seite have
			generously provided careful review with helpful corrections and
			suggestions. Marco Liebsch and Lyle Bertz also performed very
			detailed and helpful reviews of this document.
	Authors' Addresses		Authors' Addresses
	H. Anthony Chan (editor)		H. Anthony Chan (editor)
	Huawei Technologies		Caritas Institute of Higher Education
	5340 Legacy Dr. Building 3		2 Chui Ling Lane, Tseung Kwan O
	Plano, TX 75024		N.T.
	USA		Hong Kong
	Email: h.a.chan@ieee.org		Email: h.a.chan@ieee.org
	Xinpeng Wei		Xinpeng Wei
	Huawei Technologies		Huawei Technologies
	Xin-Xi Rd. No. 3, Haidian District		Xin-Xi Rd. No. 3, Haidian District
	Beijing, 100095		Beijing, 100095
	P. R. China		China
	Email: weixinpeng@huawei.com		Email: weixinpeng@huawei.com
	Jong-Hyouk Lee		Jong-Hyouk Lee
	Sangmyung University		Sejong University
	31, Sangmyeongdae-gil, Dongnam-gu		209, Neungdong-ro, Gwangjin-gu
	Cheonan 31066		Seoul
			05006
	Republic of Korea		Republic of Korea
	Email: jonghyouk@smu.ac.kr		Email: jonghyouk@sejong.ac.kr
	Seil Jeon		Seil Jeon
	Sungkyunkwan University		Sungkyunkwan University
	2066 Seobu-ro, Jangan-gu		2066 Seobu-ro, Jangan-gu
	Suwon, Gyeonggi-do		Suwon, Gyeonggi-do
	Republic of Korea		Republic of Korea
	Email: seiljeon@skku.edu		Email: seiljeon.ietf@gmail.com
	Carlos J. Bernardos (editor)		Carlos J. Bernardos (editor)
	Universidad Carlos III de Madrid		Universidad Carlos III de Madrid
	Av. Universidad, 30		Av. Universidad, 30
	Leganes, Madrid 28911		28911 Leganes, Madrid
	Spain		Spain
	Phone: +34 91624 6236		Phone: +34 91624 6236
	Email: cjbc@it.uc3m.es		Email: cjbc@it.uc3m.es
	URI: http://www.it.uc3m.es/cjbc/		URI: http://www.it.uc3m.es/cjbc/
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