DMM
Internet Engineering Task Force (IETF) H. Chan, Ed.
Internet-Draft
Request for Comments: 8818 CIHE
Category: Informational X. Wei
Intended status: Informational
ISSN: 2070-1721 Huawei Technologies
Expires: September 8, 2020
J. Lee
Sangmyung
Sejong University
S. Jeon
Sungkyunkwan University
CJ. Bernardos, Ed.
UC3M
March 7,
August 2020
Distributed Mobility Anchoring
draft-ietf-dmm-distributed-mobility-anchoring-15
Abstract
This document defines distributed mobility anchoring in terms of the
different configurations and functions to provide IP mobility
support. A network may be configured with distributed mobility
anchoring functions for both network-based or host-based mobility
support according to
support, depending on the needs of mobility support. network's needs. In a distributed mobility
anchoring environment, multiple anchors are available for mid-session
switching of an IP prefix anchor. To start a new flow or to handle a
flow not requiring IP session continuity as a mobile node moves to a
new network, the flow can be started or re-started restarted using an IP address
configured from the new IP prefix anchored to the new network. If
the flow needs to survive the change of network, there are solutions
that can be used to enable IP address mobility. This document
describes different anchoring approaches, depending on the IP
mobility needs, and how this IP address mobility is handled by the
network.
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This Internet-Draft will expire on September 8, 2020.
https://www.rfc-editor.org/info/rfc8818.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 3
3. Distributed Mobility Anchoring . . . . . . . . . . . . . . . 6
3.1. Configurations for Different Networks . . . . . . . . . . 6
3.1.1. Network-based Network-Based DMM . . . . . . . . . . . . . . . . . . 7
3.1.2. Client-based Client-Based DMM . . . . . . . . . . . . . . . . . . 8
4. IP Mobility Handling in Distributed Anchoring Environments - Environments:
Mobility Support Only When Needed . . . . . . . . . . . . . . 9
4.1. Nomadic case (no need of IP mobility): Changing to new IP
prefix/address . . . . . . . . . . . . . . . . . . . . . 10 Case
4.2. Mobility case, traffic redirection . . . . . . . . . . . 12 Case with Traffic Redirection
4.3. Mobility case, anchor relocation . . . . . . . . . . . . 15 Case with Anchor Relocation
5. Security Considerations . . . . . . . . . . . . . . . . . . . 16
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 17
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 18
8.1.
7.1. Normative References . . . . . . . . . . . . . . . . . . 18
8.2.
7.2. Informative References . . . . . . . . . . . . . . . . . 19
Acknowledgements
Contributors
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20
1. Introduction
A key requirement in distributed mobility management (DMM) [RFC7333]
is to enable traffic to avoid traversing a single mobility anchor far
from an optimal route. This document defines different
configurations, functional operations operations, and parameters for distributed
mobility anchoring and explains how to use them to avoid
unnecessarily long routes when a mobile node moves.
Companion
Other distributed mobility management documents are already
addressing address
source address selection [RFC8653], [RFC8653] and control-plane and data-plane
signaling [I-D.ietf-dmm-fpc-cpdp]. [FPC-DMM-PROTOCOL]. A number of distributed mobility
solutions have also been proposed, for example, in [I-D.seite-dmm-dma], [I-D.ietf-dmm-pmipv6-dlif],
[I-D.sarikaya-dmm-for-wifi], [I-D.yhkim-dmm-enhanced-anchoring], [DMM-DMA],
[IPV6-DMM-EXT], [DMM-WIFI], [DMM-ENHANCED-ANCHORING], and
[I-D.matsushima-stateless-uplane-vepc].
[STATELESS-UPLANE-VEPC].
Distributed mobility anchoring employs multiple anchors in the data
plane. In general, control plane control-plane functions may be separated from
data plane
data-plane functions and be centralized but may also be co-located
with the data plane data-plane functions at the distributed anchors. Different
configurations of distributed mobility anchoring are described in
Section 3.1.
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
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
as the source IP address in a flow to communicate with its
Correspondent Node (CN). When there are multiple mobility anchors
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 an
MN's network of attachment has the advantage that the packets can
simply be forwarded according to the forwarding table. However,
after the flow has been initiated, the MN may later move to another
network which that assigns a new mobility anchor to the MN. Since the new
anchor is located in a different network, the MN's assigned prefix
does not belong to the network where the MN is currently attached.
When the MN wants to continue using its assigned prefix to complete
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
continuity, since routing packets to the MN through the new network
deviates from applying default routes. The IP session continuity
needs of a flow (application) determines determine how the IP address used by
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
IP address anchored in the new network. On the other hand, if the
ongoing IP flow cannot cope with such change, mobility support is
needed. A network supporting a mix of flows both requiring and not
requiring IP mobility support will need to distinguish these flows.
2. Conventions and Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
All general mobility-related terms and their acronyms used in this
document are to be interpreted as defined in the Mobile IPv6 (MIPv6)
base specification [RFC6275], the Proxy Mobile IPv6 (PMIPv6)
specification [RFC5213], the "Mobility Related Terminologies" Mobility Terminology document [RFC3753],
and the DMM current practices Current Practices and gap analysis Gap Analysis document [RFC7429].
These include terms such as Mobile Node (MN), Correspondent Node
(CN), Home Agent (HA), Home Address (HoA), Care-of-Address (CoA),
Local Mobility Anchor (LMA), and Mobile Access Gateway (MAG).
In addition, this document uses the following terms and definitions:
IP session continuity: The ability to maintain an ongoing transport
interaction by keeping the same local endpoint IP address
throughout the lifetime of the IP socket despite the mobile host
changing its point of attachment within the IP network topology.
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
ability of applications using these IP sockets to work flawlessly.
Session continuity is essential for mobile hosts to maintain
ongoing flows without any interruption [RFC8653].
Higher layer
Higher-layer session continuity: The ability to maintain an ongoing
transport
transport- or higher layer higher-layer (e.g., application) interaction by
keeping the session indentifiers identifiers throughout the lifetime of the
session despite the mobile host changing its point of attachment
within the IP network topology. This can be achieved by using
mechanisms at the transport or higher layers.
IP address reachability: The ability to maintain the same IP address
for an extended period of time. The IP address stays the same
across independent sessions, even in the absence of any session.
The IP address may be published in a long-term registry (e.g.,
DNS) and is made available for serving incoming (e.g., TCP)
connections. IP address reachability is essential for mobile
hosts to use specific/published IP addresses [RFC8653].
IP mobility: Combination The combination of IP address reachability and session
continuity.
Anchoring (of an IP prefix/address): An IP prefix (i.e., Home network of a home address: the network that has assigned the
HoA used as the session identifier by the application running in
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,
Network Prefix (HNP)) or address (i.e., HoA) assigned for use by
an MN is topologically anchored to an anchor node when the anchor
node is able to advertise a route into the routing infrastructure
for the assigned IP prefix. The traffic using the assigned IP
address/prefix must traverse the anchor node. We can refer to the
function performed by the IP anchor node as anchoring, which is a data
plane
data-plane function.
Location Management (LM) function: control plane A control-plane function that
keeps and manages the network location information of an MN. The
location information may be a binding of the advertised IP
address/prefix, e.g.,
address/prefix (e.g., HoA or HNP, HNP) to the IP routing address of the
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
also include the Mobile Network Prefix (MNP), which is the
aggregate IP prefix delegated to the MR to assign IP prefixes for
use by the Mobile Network Nodes (MNNs) in the mobile network.
In a client-server protocol model, secure (i.e., authenticated and
authorized) location query and update messages may be exchanged
between a Location Management client (LMc) and a Location
Management server (LMs), where the location information can be
updated or queried from the LMc. Optionally, there may be a
Location Management proxy (LMp) between LMc and LMs.
With separation of control plane and data plane, the LM function
is in the control plane. It may be a logical function at the
control plane
control-plane node, control plane control-plane anchor, or mobility controller.
It may be distributed or centralized.
Forwarding Management (FM) function: packet Packet interception and
forwarding to/from the IP address/prefix assigned for use by the
MN, based on the internetwork location information, either to the
destination or to some other network element that knows how to
forward the packets to their destination.
This function may be used to achieve traffic indirection. With
separation of control plane and data plane, the FM function may
split into a an FM function in the data plane (FM-DP) and a an FM
function in the control plane (FM-CP).
FM-DP may be distributed with distributed mobility management. It
may be a function in a data plane data-plane anchor or data plane data-plane node.
FM-CP may be distributed or centralized. It may be a function in
a control plane control-plane node, control plane anchor control-plane anchor, or mobility
controller.
Home Control-Plane Anchor (Home-CPA or H-CPA): The Home-CPA function
hosts the mobile node (MN)'s MN's mobility session. There can be more than one
mobility session for a mobile node node, and those sessions may be
anchored on the same or different Home-CPA's. The home-CPA Home-CPA will
interface with the home-DPA Home-DPA for managing the forwarding state.
Home Data Plane Data-Plane Anchor (Home-DPA or H-DPA): The Home-DPA is the
topological anchor for the MN's IP address/ prefix(es). address/prefix(es). The Home-
DPA is chosen by the Home-CPA on a session- session basis. The Home-DPA is
in the forwarding path for all the mobile node's IP traffic.
Access Control Plane Control-Plane Node (Access-CPN or A-CPN): The Access-CPN is
responsible for interfacing with the mobile node's Home-CPA and
with the Access-DPN. The Access-CPN has a protocol interface to
the Home-CPA.
Access Data Plane Data-Plane Node (Access-DPN or A-DPN): The Access-DPN
function is hosted on the first-hop router where the mobile node
is attached. This function is not hosted on a layer-2 Layer 2 bridging
device such as a an eNode(B) or Access Point.
3. Distributed Mobility Anchoring
3.1. Configurations for Different Networks
We next describe some configurations with multiple distributed
anchors. To cover the widest possible spectrum of scenarios, we
consider architectures in which the control and data planes are
separated. We analyze where LM and FM functions -- functions, which are specific
sub-functions involved in mobility management -- management, can be placed when
looking at the different scenarios with distributed anchors.
3.1.1. Network-based Network-Based DMM
Figure 1 shows a general scenario for network-based distributed
mobility management.
The main characteristics of a network-based DMM solution are:
o
* There are multiple data plane data-plane anchors, each with a an FM-DP
function.
o
* The control plane may either be distributed (not shown in the
figure) or centralized (as shown in the figure).
o
* The control plane and the data plane (Control Plane Control-Plane Anchor -- CPA
-- (CPA) and the Data Plane Anchor -- DPA) (DPA) may be co-located
or not. may not be co-located. If the CPA is co-located with the
distributed DPAs, then there are multiple co-located CPA-DPA
instances (not shown in the figure).
o
* An IP prefix/address IP1 (anchored to the DPA with IP address
IPa1) is assigned for use to a an MN. The MN uses this IP1 address
to communicate with CNs (not shown in the figure).
o
* The location management (LM) function may be co-located or split
(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
may be distributed or centralized.
____________ Network
___/ \___________
/ +-----+ \___
( |LMs | Control Control- \
/ +-.---+ plane \
/ +--------.---+ functions \
( |CPA: . | in the )
( |FM-CP, LMc | network )
( +------------+ \
/ . . \
( . . )
( . . )
( . . \
\ +------------+ +------------+Distributed )
( |DPA(IPa1): | |DPA(IPa2): |DPAs )
( |anchors IP1 | |anchors IP2 | _/
\ |FM-DP | |FM-DP | etc. /
\ +------------+ +------------+ /
\___ Data plane Data-plane _____/
\______ functions /
\__________________/
+------------+
|MN(IP1) | Mobile node attached
|flow(IP1,..)| to the network
+------------+
Figure 1: Network-based Network-Based DMM configuration Configuration
3.1.2. Client-based Client-Based DMM
Figure 2 shows a general scenario for client-based distributed
mobility management. In this configuration, the mobile node performs
Control Plane
Control-Plane Node (CPN) and Data Plane Data-Plane Node (DPN) mobility
functions, namely the forwarding management and location management
(client) roles.
+-----+
|LMs |
+-.---+
+--------.---+
|CPA: . |
|FM-CP, LMp |
+------------+
. .
. .
. .
. .
+------------+ +------------+ Distributed
|DPA(IPa1): | |DPA(IPa2): | DPAs
|anchors IP1 | |anchors IP2 |
|FM-DP | |FM-DP | etc.
+------------+ +------------+
+------------+
|MN(IP1) |Mobile node
|flow(IP1,..)|using IP1
|FM, LMc |anchored to
+------------+DPA(IPa1)
Figure 2: Client-based Client-Based DMM configuration Configuration
4. IP Mobility Handling in Distributed Anchoring Environments - Environments: Mobility
Support Only When Needed
IP mobility support may be provided only when needed instead of being
provided by default. Three cases can be considered:
o
* Nomadic case: no No address continuity is required. The IP address
used by the MN changes after a movement and traffic using the old
address is disrupted. If session continuity is required, then it
needs to be provided by a solution running at L4 Layer 4 or above.
o
* Mobility case, case with traffic redirection: address Address continuity is
required. When the MN moves, the previous anchor still anchors
the traffic using the old IP address, address and forwards it to the new
MN's location. The MN obtains a new IP address anchored to the
new location, location and preferably uses it for new communications, communications
established while connected at the new location.
o
* Mobility case, case with anchor relocation: address Address continuity is
required. In this case case, the route followed by the traffic is optimized,
optimized by using some means for traffic indirection to deviate
from default routes.
A straightforward choice of mobility anchoring is the following: the
MN's chooses
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
the flow was initiated. As such, traffic belonging to this flow
traverses the MN's mobility anchor [I-D.seite-dmm-dma]
[I-D.ietf-dmm-pmipv6-dlif]. [DMM-DMA] [IPV6-DMM-EXT].
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,
when a 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
MN's interface. In addition to configuring new link-local addresses,
the MN configures from this prefix an IP address which that is typically a
dynamic IP address (meaning that this address is only used while the
MN is attached to this access router, and therefore so the IP address configured by
the MN dynamically changes when attaching to a different access
network). It then uses this IP address when a flow is initiated.
Packets from this flow addressed to the MN are simply forwarded
according to the forwarding table.
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
different access networks. The network may advertise these prefixes
with cost options [I-D.mccann-dmm-prefixcost] [PREFIX-COST] so that the mobile node may choose
the one with the least cost. In addition, the IP prefixes/addresses
provided by the network may be of different types regarding whether
mobility support is supported [RFC8653]. A An MN will need to choose
which IP prefix/address to use for each flow according to whether or
not it needs IP mobility support or not, using support, for example example, using the mechanisms
described in [RFC8653].
4.1. Nomadic case (no need of IP mobility): Changing to new IP prefix/
address Case
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
are simplified as shown in Figure 3.
Net1 Net2
+---------------+ +---------------+
|AR1 | AR is changed |AR2 |
+---------------+ -------> +---------------+
|CPA: | |CPA: |
|---------------| |---------------|
|DPA(IPa1): | |DPA(IPa2): |
|anchors IP1 | |anchors IP2 |
+---------------+ +---------------+
+...............+ +---------------+
.MN(IP1) . MN moves |MN(IP2) |
.flow(IP1,...) . =======> |flow(IP2,...) |
+...............+ +---------------+
Figure 3: Changing to a new New IP address/prefix Address/Prefix
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
the new network.
Regardless of whether or not IP mobility is needed, if the flow has
not terminated before the MN moves to a new network, the flow may
subsequently restart using the new IP address assigned from the new
network.
When IP session continuity is needed, even if an application flow is
ongoing as the MN moves, it may still be desirable for the
application flow to change to using the new IP prefix configured in
the new network. The application flow may then be closed at the IP
level and then be restarted using a new IP address configured in the
new network. Such a change in the IP address used by the application
flow may be enabled using a higher layer higher-layer mobility support which that is not
in the scope of this document.
In Figure 3, a flow initiated while the MN was using the IP prefix
IP1 --
IP1, anchored to a previous access router AR1 in network Net1 -- Net1, has
terminated before the MN moves to a new network Net2. After moving
to Net2, the MN uses the new IP prefix IP2 -- IP2, anchored to a new access
router AR2 in network Net2 -- Net2, to start a new flow. Packets may then be
forwarded without requiring IP layer IP-layer mobility support.
An example call flow is outlined in Figure 4. A An MN attaches to AR1,
which sends a router advertisement (RA) including information about
the prefix assigned to the MN, from which the MN configures an IP
address (IP1). This address is used for new communications, for example
example, with a correspondent node (CN). If the MN moves to a new
network and attaches to AR2, the process is repeated (MN (the MN obtains
a new IP address, IP2, from AR2). Since the IP address (IP1)
configured at the previously visited network is not valid at the
current attachment point, and any existing flows have to be reestablished
using IP2.
Note that in these scenarios, if there is no mobility support
provided by L4 Layer 4 or above, application traffic would stop.
MN AR1 AR2 CN
|MN attaches to AR1: | | |
|acquires MN-ID and profile | |
|--RS---------------->| | |
| | | |
|<----------RA(IP1)---| | |
| | | |
Assigned prefix IP1 | | |
IP1 address configuration | |
| | | |
|<-Flow(IP1,IPcn,...)-+------------------------------------------>|
| | | |
|MN detaches from AR1 | | |
|MN attaches to AR2 | | |
| | | |
|--RS------------------------------>| |
| | | |
|<--------------RA(IP2)-------------| |
| | | |
Assigned prefix IP2 | | |
IP2 address configuration | |
| | | |
|<-new Flow(IP2,IPcn,...)-----------+---------------------------->|
| | | |
Figure 4: Re-starting Restarting a flow Flow with new New IP prefix/address Prefix/Address
4.2. Mobility case, traffic redirection Case with Traffic Redirection
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
mobility anchor remains playing that role and forwards traffic to a
new locator in the new network, and (ii) the mobility anchor (data (data-
plane function) is changed but binds the MN's transferred IP address/
prefix. The latter enables optimized routes but requires some data data-
plane node that enforces traffic indirection. Next, we We focus on the first case.
case in this section. The second one case is addressed in Section 4.3.
Mobility support can be provided by using mobility management
methods, such as the several approaches surveyed in the following academic
papers ([Paper-Distributed.Mobility],
[Paper-Distributed.Mobility.PMIP]
papers: [IEEE-DISTRIBUTED-MOBILITY], [PMIP-DMA], and
[Paper-Distributed.Mobility.Review]).
[DMM-MOBILE-INTERNET]. After moving, a certain MN's traffic flow may
continue using the IP prefix from the prior network of attachment.
Yet, some time later, the application generating this traffic flow
may be closed. If the application is started again, the new flow may
not need to use the prior network's IP address to avoid having to
invoke IP mobility support. This may be the case where a dynamic IP
prefix/address, rather than a permanent one, is used. Packets
belonging to this flow may then use the new IP prefix (the one
allocated in the network where the flow is being initiated). Routing
is again kept simpler without employing IP mobility and will remain
so as long as the MN MN, which is now in the new network network, does not 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 attaches to AR1: | | |
|acquires MN-ID and profile | |
|--RS---------------->| | |
| | | |
|<----------RA(IP1)---| | |
| | | |
Assigned prefix IP1 | | |
IP1 address configuration | |
| | | |
|<-Flow(IP1,IPcn,...)-+------------------------------------------>|
| | | |
|MN detaches from AR1 | | |
|MN attaches to AR2 | | |
| | | |
|--RS------------------------------>| |
(some IP mobility support solution)
|<--------------RA(IP2,IP1)---------| |
| | | |
| +<-Flow(IP1,IPcn,...)---------------------->|
| +<===========>+ |
|<-Flow(IP1,IPcn,...)-------------->+ |
| | | |
Assigned prefix IP2 | | |
IP2 address configuration | |
| | | |
Flow(IP1,IPcn) terminates | |
| | | |
|<-new Flow(IP2,IPcn,...)-----------+---------------------------->|
| | | |
Figure 5: A flow continues to use the Flow Using IP prefix Prefix from its home network Home Network after MN has moved to a new network
An example call flow in this case is outlined in Figure 5. In this
example, the AR1 plays the role of FM-DP entity and redirects the
traffic (e.g., using an IP tunnel) to AR2. Moved
Another solution could be to place an FM-DP entity closer to the CN
network to perform traffic 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
+---------------+ +---------------+
|AR1 | |AR2 |
+---------------+ +---------------+
|CPA: | |CPA: |
| | |LM:IP1 at IPa1 |
|---------------| IP1 (anchored to Net1) |---------------|
|DPA(IPa1): | is redirected to Net2 |DPA(IPa2): |
|anchors IP1 | =======> |anchors IP2 |
|FM:IP1 via IPa2| |FM:IP1 via IPa1|
+---------------+ +---------------+
+...............+ +---------------+
.MN(IP1) . MN moves |MN(IP2,IP1) |
.flow(IP1,...) . =======> |flow(IP1,...) |
. . |flow(IP2,...) |
+...............+ +---------------+
Figure 6: Anchor redirection Redirection
Multiple instances of DPAs (at access routers), which are providing
IP prefixes to the MNs, are needed to provide distributed mobility
anchoring in an appropriate configuration such as those described 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.
4.3. Mobility case, anchor relocation Case with Anchor Relocation
We focus next on the case where the mobility anchor (data plane (data-plane
function) is changed but binds the MN's transferred IP address/
prefix. This enables optimized routes but requires some data plane data-plane
node that enforces traffic indirection.
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
address of the flow is in the home network of the flow (i.e.,
different from the current network of attachment). A centralized
mobility management mechanism may employ indirection from the anchor
in the home network to the current network of attachment. Yet Yet, it
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
significantly longer than the direct route between them). An
alternative is to move the IP prefix/address anchoring to the new
network.
The IP prefix/address anchoring may move without changing the IP
prefix/address of the flow. The LM function in Figure 1 in of
Section 3.1.1 is implemented as shown in Figure 7.
Net1 Net2
+---------------+ +---------------+
|AR1 | |AR2 |
+---------------+ +---------------+
|CPA: | |CPA: |
|LM:IP1 at IPa1 | |LM:IP1 at IPa2 |
| changes to | | |
| IP1 at IPa2 | | |
|---------------| |---------------|
|DPA(IPa1): | IP1 anchoring effectively moved |DPA(IPa2): |
|anchored IP1 | =======> |anchors IP2,IP1|
+---------------+ +---------------+
+...............+ +---------------+
.MN(IP1) . MN moves |MN(IP2,IP1) |
.flow(IP1,...) . =======> |flow(IP1,...) |
+...............+ +---------------+
Figure 7: Anchor relocation Relocation
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
original IP prefix/address of the flow to the new network.
One way to accomplish such a move is to use a centralized routing
protocol, but such a solution may present some scalability concerns
and its applicability is typically limited to small networks. One
example of this type of solution is described in
[I-D.ietf-rtgwg-atn-bgp]. [BGP-ATN-IPS]. When a
an MN associates with an anchor anchor, the anchor injects the mobile's MN's prefix
into the global routing system. If the MN moves to a new anchor, the
old anchor withdraws the /64 and the new anchor injects it instead.
5. Security Considerations
As stated in [RFC7333], "a DMM solution MUST support any security
protocols and mechanisms needed to secure the network and to make
continuous security improvements". It "MUST NOT introduce new
security risks".
There are different potential deployment models of a DMM solution.
The present document has presented 3 three different scenarios for
distributed anchoring: (i) nomadic case, (ii) mobility case with
traffic redirection, and (iii) mobility case with anchor relocation.
Each of them these cases has different security requirements, and the
actual security mechanisms would depend on the specifics of each solution/
scenario.
As general rules, for the first distributed anchoring scenario
(nomadic case), no additional security consideration is needed, as
this does not involve any additional mechanism at L3. Layer 3. If
session connectivity is required, the L4 Layer 4 or above solution used
to provide it MUST also provide the required authentication and
security.
The second and third distributed anchoring scenarios (mobility case)
involve mobility signalling signaling among the mobile node and the control and
data control-
plane and data-plane anchors. The control-plane messages exchanged
between these entitites entities MUST be protected using end-to-end security
associations with data-integrity and data-origination capabilities.
IPsec [RFC8221] ESP Encapsulating Security Payload (ESP) in transport
mode with mandatory integrity protection SHOULD be used for
protecting the signaling messages.
IKEv2 Internet Key Exchange Protocol
Version 2 (IKEv2) [RFC8247] SHOULD be used to set up security
associations between the data data-plane and control plane control-plane anchors. Note
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
commands or updates that are made by the control-plane protocol.
6. IANA Considerations
This document presents has no IANA considerations. actions.
7. Contributors
Alexandre Petrescu and Fred Templin had contributed to earlier
versions of this document regarding distributed anchoring for
hierarchical network and References
7.1. Normative References
[RFC2119] Bradner, S., "Key words 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 use in enterprise network. These works have been
referenced. While some of these authors have taken the work RFCs 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
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3753] Manner, J., Ed. Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related
Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004,
<https://www.rfc-editor.org/info/rfc3753>.
[RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
RFC 5213, DOI 10.17487/RFC5213, August 2008,
<https://www.rfc-editor.org/info/rfc5213>.
[RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July
2011, <https://www.rfc-editor.org/info/rfc6275>.
[RFC7333] Chan, H., Ed., Liu, D., Seite, P., Yokota, H., and J.
Korhonen, "Requirements for Distributed Mobility
Management", RFC 7333, DOI 10.17487/RFC7333, August 2014,
<https://www.rfc-editor.org/info/rfc7333>.
[RFC7429] Liu, D., Ed., Zuniga, JC., Ed., Seite, P., Chan, H., and
CJ. Bernardos, "Distributed Mobility Management: Current
Practices and Gap Analysis", RFC 7429,
DOI 10.17487/RFC7429, January 2015,
<https://www.rfc-editor.org/info/rfc7429>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8221] Wouters, P., Migault, D., Mattsson, J., Nir, Y., and T.
Kivinen, "Cryptographic Algorithm Implementation
Requirements and Usage Guidance for Encapsulating Security
Payload (ESP) and Authentication Header (AH)", RFC 8221,
DOI 10.17487/RFC8221, October 2017,
<https://www.rfc-editor.org/info/rfc8221>.
[RFC8247] Nir, Y., Kivinen, T., Wouters, P., and D. Migault,
"Algorithm Implementation Requirements and Usage Guidance
for the Internet Key Exchange Protocol Version 2 (IKEv2)",
RFC 8247, DOI 10.17487/RFC8247, September 2017,
<https://www.rfc-editor.org/info/rfc8247>.
8.2.
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.
Moreno, "A Simple BGP-based Mobile Routing System for the
Aeronautical Telecommunications Network", draft-ietf-
rtgwg-atn-bgp-05 (work in progress), January 2020.
[I-D.matsushima-stateless-uplane-vepc]
Matsushima, S. and R. Wakikawa, "Stateless user-plane
architecture for virtualized EPC (vEPC)", draft-
matsushima-stateless-uplane-vepc-06 (work in progress),
March 2016.
[I-D.mccann-dmm-prefixcost]
McCann, P. and J. Kaippallimalil, "Communicating Prefix
Cost to Mobile Nodes", draft-mccann-dmm-prefixcost-03
(work in progress), April 2016.
[I-D.sarikaya-dmm-for-wifi]
Sarikaya, B. and L. Li, "Distributed Mobility Management
Protocol for WiFi Users in Fixed Network", draft-sarikaya-
dmm-for-wifi-05 (work Work in progress), October 2017.
[I-D.seite-dmm-dma]
Progress, Internet-Draft, draft-ietf-rtgwg-atn-bgp-06, 30
June 2020,
<https://tools.ietf.org/html/draft-ietf-rtgwg-atn-bgp-06>.
[DMM-DMA] Seite, P., Bertin, P., and J. Lee, "Distributed Mobility
Anchoring", draft-seite-dmm-dma-07 (work Work in progress), Progress, Internet-Draft, draft-seite-
dmm-dma-07, 6 February 2014.
[I-D.yhkim-dmm-enhanced-anchoring] 2014,
<https://tools.ietf.org/html/draft-seite-dmm-dma-07>.
[DMM-ENHANCED-ANCHORING]
Kim, Y. and S. Jeon, "Enhanced Mobility Anchoring in
Distributed Mobility Management", draft-yhkim-dmm-
enhanced-anchoring-05 (work Work in progress), Progress,
July 2016.
[Paper-Distributed.Mobility]
Lee, J., Bonnin, J., Seite, P., and H. Chan, "Distributed
IP Mobility Management from the Perspective of the IETF:
Motivations, Requirements, Approaches, Comparison, and
Challenges", IEEE Wireless Communications, October 2013.
[Paper-Distributed.Mobility.PMIP]
Chan, H., "Proxy Mobile IP with Distributed Mobility
Anchors", Proceedings of GlobeCom Workshop on Seamless
Wireless Mobility, December 2010.
[Paper-Distributed.Mobility.Review] 2016, <https://tools.ietf.org/html/draft-yhkim-dmm-
enhanced-anchoring-05>.
[DMM-MOBILE-INTERNET]
Chan, H., Yokota, H., Xie, J., Seite, P., and D. Liu,
"Distributed and Dynamic Mobility Management in Mobile
Internet: Current Approaches and Issues", Journal of
Communications, Vol. 6, No. 1, February 2011.
[RFC6459] Korhonen, J., Ed., Soininen, J., Patil, B., Savolainen,
T., Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation
Partnership Project (3GPP) Evolved Packet System (EPS)",
RFC 6459, DOI 10.17487/RFC6459, January 2012,
<https://www.rfc-editor.org/info/rfc6459>.
[RFC8653] Yegin, A., Moses, D.,
[DMM-WIFI] Sarikaya, B. and S. Jeon, "On-Demand L. Li, "Distributed Mobility
Management", RFC 8653, DOI 10.17487/RFC8653, October 2019,
<https://www.rfc-editor.org/info/rfc8653>.
Authors' Addresses Management
Protocol for WiFi Users in Fixed Network", Work in
Progress, Internet-Draft, draft-sarikaya-dmm-for-wifi-05,
30 October 2017, <https://tools.ietf.org/html/draft-
sarikaya-dmm-for-wifi-05>.
[FPC-DMM-PROTOCOL]
Matsushima, S., Bertz, L., Liebsch, M., Gundavelli, S.,
Moses, D., and C. Perkins, "Protocol for Forwarding Policy
Configuration (FPC) in DMM", Work in Progress, Internet-
Draft, draft-ietf-dmm-fpc-cpdp-13, 8 March 2020,
<https://tools.ietf.org/html/draft-ietf-dmm-fpc-cpdp-13>.
[IEEE-DISTRIBUTED-MOBILITY]
Lee, J., Bonnin, J., Seite, P., and H. A. Chan,
"Distributed IP mobility management from the perspective
of the IETF: motivations, requirements, approaches,
comparison, and challenges", IEEE Wireless Communications,
vol. 20, no. 5, pp. 159-168, October 2013.
[IPV6-DMM-EXT]
Bernardos, CJ., Oliva, A., Giust, F., Zuniga, JC., and A.
Mourad, "Proxy Mobile IPv6 extensions for Distributed
Mobility Management", Work in Progress, Internet-Draft,
draft-ietf-dmm-pmipv6-dlif-06, March 2020,
<https://tools.ietf.org/html/draft-ietf-dmm-pmipv6-dlif-
06>.
[PMIP-DMA] Chan, H., "Proxy mobile IP with distributed mobility
anchors", IEEE Globecom Workshops Miami, FL, 2010, pp.
16-20, December 2010.
[PREFIX-COST]
McCann, P. and J. Kaippallimalil, "Communicating Prefix
Cost to Mobile Nodes", Work in Progress, Internet-Draft,
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,
T., Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation
Partnership Project (3GPP) Evolved Packet System (EPS)",
RFC 6459, DOI 10.17487/RFC6459, January 2012,
<https://www.rfc-editor.org/info/rfc6459>.
[RFC8653] Yegin, A., Moses, D., and S. Jeon, "On-Demand Mobility
Management", RFC 8653, DOI 10.17487/RFC8653, October 2019,
<https://www.rfc-editor.org/info/rfc8653>.
[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
H. Anthony Chan (editor)
Huawei Technologies
5340 Legacy Dr. Building 3
Plano, TX 75024
USA
Caritas Institute of Higher Education
2 Chui Ling Lane, Tseung Kwan O
N.T.
Hong Kong
Email: h.a.chan@ieee.org
Xinpeng Wei
Huawei Technologies
Xin-Xi Rd. No. 3, Haidian District
Beijing, 100095
P. R.
China
Email: weixinpeng@huawei.com
Jong-Hyouk Lee
Sangmyung
Sejong University
31, Sangmyeongdae-gil, Dongnam-gu
Cheonan 31066
209, Neungdong-ro, Gwangjin-gu
Seoul
05006
Republic of Korea
Email: jonghyouk@smu.ac.kr jonghyouk@sejong.ac.kr
Seil Jeon
Sungkyunkwan University
2066 Seobu-ro, Jangan-gu
Suwon, Gyeonggi-do
Republic of Korea
Email: seiljeon@skku.edu seiljeon.ietf@gmaiil.com
Carlos J. Bernardos (editor)
Universidad Carlos III de Madrid
Av. Universidad, 30
28911 Leganes, Madrid 28911
Spain
Phone: +34 91624 6236
Email: cjbc@it.uc3m.es
URI: http://www.it.uc3m.es/cjbc/