draft-ietf-dmm-distributed-mobility-anchoring-11.txt   draft-ietf-dmm-distributed-mobility-anchoring-12.txt 
DMM H. Chan, Ed. DMM H. Chan, Ed.
Internet-Draft X. Wei Internet-Draft X. Wei
Intended status: Informational Huawei Technologies Intended status: Informational Huawei Technologies
Expires: March 2, 2019 J. Lee Expires: August 2, 2019 J. Lee
Sangmyung University Sangmyung University
S. Jeon S. Jeon
Sungkyunkwan University Sungkyunkwan University
CJ. Bernardos, Ed. CJ. Bernardos, Ed.
UC3M UC3M
August 29, 2018 January 29, 2019
Distributed Mobility Anchoring Distributed Mobility Anchoring
draft-ietf-dmm-distributed-mobility-anchoring-11 draft-ietf-dmm-distributed-mobility-anchoring-12
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 the support according to the needs of mobility support. In a distributed
distributed mobility anchoring environment, multiple anchors are mobility anchoring environment, multiple anchors are available for
available for mid-session switching of an IP prefix anchor. To start mid-session switching of an IP prefix anchor. To start a new flow or
a new flow or to handle a flow not requiring IP session continuity as to handle a flow not requiring IP session continuity as a mobile node
a mobile node moves to a new network, the flow can be started or re- moves to a new network, the flow can be started or re-started using
started using a new IP address configured from the new IP prefix an IP address configured from the new IP prefix anchored to the new
which is anchored to the new network. The mobility functions and network. If the flow needs to survive the change of network, there
their operations and parameters are general for different are solutions that can be used to enable IP address mobility. This
configurations. document describes different anchoring approaches, depending on the
IP mobility needs, and how this IP address mobility is handled by the
network.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 2, 2019.
This Internet-Draft will expire on March 2, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
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the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
skipping to change at page 2, line 39 skipping to change at page 2, line 40
Mobility Support Only When Needed . . . . . . . . . . . . . . 7 Mobility Support Only When Needed . . . . . . . . . . . . . . 7
4.1. Nomadic case (no need of IP mobility): Changing to new IP 4.1. Nomadic case (no need of IP mobility): Changing to new IP
prefix/address . . . . . . . . . . . . . . . . . . . . . 8 prefix/address . . . . . . . . . . . . . . . . . . . . . 8
4.2. Mobility case, traffic redirection . . . . . . . . . . . 10 4.2. Mobility case, traffic redirection . . . . . . . . . . . 10
4.3. Mobility case, anchor relocation . . . . . . . . . . . . 12 4.3. Mobility case, anchor relocation . . . . . . . . . . . . 12
5. Security Considerations . . . . . . . . . . . . . . . . . . . 13 5. Security Considerations . . . . . . . . . . . . . . . . . . . 13
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
8.1. Normative References . . . . . . . . . . . . . . . . . . 14 8.1. Normative References . . . . . . . . . . . . . . . . . . 14
8.2. Informative References . . . . . . . . . . . . . . . . . 16 8.2. Informative References . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction 1. Introduction
A key requirement in distributed mobility management [RFC7333] is to A key requirement in distributed mobility management [RFC7333] is to
enable traffic to avoid traversing a single mobility anchor far from enable traffic to avoid traversing a single mobility anchor far from
an optimal route. This document defines different configurations, an optimal route. This document defines different configurations,
functional operations and parameters for distributed mobility functional operations and parameters for distributed mobility
anchoring and explains how to use them to make the route changes to anchoring and explains how to use them to avoid unnecessarily long
avoid unnecessarily long routes. routes when a mobile node moves.
Companion distributed mobility management documents are already Companion distributed mobility management documents are already
addressing the architecture and deployment addressing the architecture and deployment
[I-D.ietf-dmm-deployment-models], source address selection [I-D.ietf-dmm-deployment-models], source address selection
[I-D.ietf-dmm-ondemand-mobility], and control-plane data-plane [I-D.ietf-dmm-ondemand-mobility], and control-plane data-plane
signaling [I-D.ietf-dmm-fpc-cpdp]. A number of distributed mobility signaling [I-D.ietf-dmm-fpc-cpdp]. A number of distributed mobility
solutions have also been proposed, for example, in solutions have also been proposed, for example, in
[I-D.seite-dmm-dma], [I-D.bernardos-dmm-pmipv6-dlif], [I-D.seite-dmm-dma], [I-D.ietf-dmm-pmipv6-dlif],
[I-D.sarikaya-dmm-for-wifi], [I-D.yhkim-dmm-enhanced-anchoring], and [I-D.sarikaya-dmm-for-wifi], [I-D.yhkim-dmm-enhanced-anchoring], and
[I-D.matsushima-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.
skipping to change at page 3, line 33 skipping to change at page 3, line 35
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 a
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 which 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
and the built MN IP address do not belong to the network where the MN does not belong to the network where the MN is currently attached.
is currently attached.
When the MN wants to continue using its assigned prefix and IP When the MN wants to continue using its assigned prefix to complete
address to complete ongoing data sessions after it moved to a new ongoing data sessions after it has moved to a new network, the
network, the network needs to provide support for IP address- and network needs to provide support for the MN's IP address -- and
session continuity, since routing packets to the MN through the new session continuity, since routing packets to the MN through the new
network deviates from applying default routes. The IP session network deviates from applying default routes. The IP session
continuity needs of a flow (application) determines the how the IP continuity needs of a flow (application) determines how the IP
address used by the traffic of this flow has to be anchored. If the address used by this flow has to be anchored. If the ongoing IP flow
ongoing IP flow can cope with an IP prefix/address change, the flow can cope with an IP prefix/address change, the flow can be
can be reinitiated with a new IP address anchored in the new network. reinitiated with a new IP address anchored in the new network. On
On the other hand, if the ongoing IP flow cannot cope with such the other hand, if the ongoing IP flow cannot cope with such change,
change, mobility support is needed. A network supporting a mix of mobility support is needed. A network supporting a mix of flows both
flows both requiring and not requiring IP mobility support will need requiring and not requiring IP mobility support will need to
to distinguish these flows. distinguish these flows.
2. Conventions and Terminology 2. Conventions and Terminology
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 Related Terminologies"
[RFC3753], and the DMM current practices and gap analysis [RFC7429]. [RFC3753], and the DMM current practices and gap analysis [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: In addition, this document uses the following terms:
Home network of a home address: the network that has assigned the Home network of a home address: the network that has assigned the
HoA used as the session identifier by the application running in HoA used as the session identifier by the application running in
an MN. The MN may be running multiple application sessions, and an MN. The MN may be running multiple application sessions, and
each of these sessions can have a different home network. each of these sessions can have a different home network.
Anchor (of an IP prefix/address): An IP prefix, i.e., Home Network Anchoring (of an IP prefix/address): An IP prefix, i.e., Home
Prefix (HNP), or address, i.e., HoA, assigned for use by an MN is Network Prefix (HNP), or address, i.e., HoA, assigned for use by
topologically anchored to an anchor node when the anchor node is an MN is topologically anchored to an anchor node when the anchor
able to advertise a connected route into the routing node is able to advertise a connected route into the routing
infrastructure for the assigned IP prefix. The traffic using the infrastructure for the assigned IP prefix. The traffic using the
assigned IP address/prefix must traverse the anchor node. We can assigned IP address/prefix must traverse the anchor node. We can
refer to the function performed by IP anchor node as anchoring, refer to the function performed by IP anchor node as anchoring,
which is a data plane function. which is a data plane function.
Location Management (LM) function: control plane function that keeps Location Management (LM) function: control plane function that keeps
and manages the network location information of an MN. The 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) providing a mobile network of When the MN is a mobile router (MR), the location information will
mobile network nodes (MNN), the location information will also also include the mobile network prefix (MNP), which is the
include the mobile network prefix (MNP), which is the aggregate IP aggregate IP prefix delegated to the MR to assign IP prefixes for
prefix delegated to the MR to assign IP prefixes for use by the use by the mobile network nodes (MNNs) in the mobile network.
MNNs in the mobile network.
In a client-server protocol model, location query and update In a client-server protocol model, location query and update
messages may be exchanged between a Location Management client messages may be exchanged between a Location Management client
(LMc) and a Location Management server (LMs), where the location (LMc) and a Location Management server (LMs), where the location
information can be updated to or queried from the LMc. information can be updated to or queried from the LMc.
Optionally, there may be a Location Management proxy (LMp) between Optionally, there may be a Location Management proxy (LMp) between
LMc and LMs. 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
skipping to change at page 5, line 44 skipping to change at page 5, line 44
consider architectures in which the control and data planes are consider architectures in which the control and data planes are
separated, as described in [I-D.ietf-dmm-deployment-models]. separated, as described in [I-D.ietf-dmm-deployment-models].
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 (i.e., DPA instances), each o There are multiple data plane anchors, each with a FM-DP function.
with a FM-DP function.
o The control plane may either be distributed (not shown in the o 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 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 -- and Data Plane Anchor -- DPA) may be co-located or not. If the
CPA is co-located with the distributed DPAs, then there are CPA is co-located with the distributed DPAs, then there are
multiple co-located CPA-DPA instances (not shown in the figure). multiple co-located CPA-DPA instances (not shown in the figure).
o An IP prefix/address IP1 (anchored to the DPA with IP address o An IP prefix/address IP1 (anchored to the DPA with IP address
IPa1) is assigned for use to a MN. The MN uses this IP1 address IPa1) is assigned for use to a 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 o The location management (LM) function may be co-located or split
skipping to change at page 7, line 37 skipping to change at page 7, line 37
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 Support Only When Needed Mobility 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 o Nomadic case: no address continuity is required. The IP address
used by the MN changes after movement and traffic using 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 L4 or above.
o Mobility case, traffic redirection: address continuity is o Mobility case, 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
traffic using the old IP address, and forwards it to the new MN's the traffic using the old IP address, and forwards it to the new
location. The MN obtains a new IP address anchored at the new MN's location. The MN obtains a new IP address anchored to the
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. o Mobility case, anchor relocation: address continuity is required.
In this case the route followed by the traffic is optimized, by In this case the route followed by the traffic is optimized, by
using some means for traffic indirection to deviate from default using some means for traffic indirection to deviate from default
routes. 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 of packets belonging to an IP flow, MN's chooses as source IP address for packets belonging to an IP
an address allocated by the network the MN is attached to when the flow, an address allocated by the network the MN is attached to when
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 [I-D.seite-dmm-dma]
[I-D.bernardos-dmm-pmipv6-dlif]. [I-D.ietf-dmm-pmipv6-dlif].
The IP prefix/address at the MN's side of a flow may be anchored at The IP prefix/address at the MN's side of a flow may be anchored to
the access router to which the MN is attached. For example, when a the access router to which the MN is attached. For example, when a
MN attaches to a network (Net1) or moves to a new network (Net2), 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 IP prefix from the attached network is assigned to the MN's
interface. In addition to configuring new link-local addresses, the interface. In addition to configuring new link-local addresses, the
MN configures from this prefix an IP address which is typically a MN configures from this prefix an IP address which is typically a
dynamic IP address. It then uses this IP address when a flow is dynamic IP address. It then uses this IP address when a flow is
initiated. Packets to the MN in this flow are simply forwarded initiated. Packets from this flow addressed to the MN are simply
according to the forwarding table. forwarded 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 [I-D.mccann-dmm-prefixcost] so that the mobile node
may choose the one with the least cost. In addition, these IP may choose the one with the least cost. In addition, these IP
prefixes/addresses may be of different types regarding whether prefixes/addresses may be of different types regarding whether
mobility support is needed [I-D.ietf-dmm-ondemand-mobility]. A flow mobility support is needed [I-D.ietf-dmm-ondemand-mobility]. A MN
will need to choose the appropriate one according to whether it needs will need to choose which IP prefix/address to use for each flow
IP mobility support. according to whether it needs IP mobility support or not.
4.1. Nomadic case (no need of IP mobility): Changing to new IP prefix/ 4.1. Nomadic case (no need of IP mobility): Changing to new IP prefix/
address 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
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.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 Regardless of whether IP mobility is needed, if the flow has not
terminated before the MN moves to a new network, the flow may 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 a flow is ongoing as When IP session continuity is needed, even if a flow is ongoing as
the MN moves, it may still be desirable for the flow to change to the MN moves, it may still be desirable for the flow to change to
using the new IP prefix configured in the new network. The flow may using the new IP prefix configured in the new network. The flow may
then close and then restart using a new IP address configured in the then close and then restart using a new IP address configured in the
new network. Such a change in the IP address of the flow may be new network. Such a change in the IP address of the flow may be
enabled using a higher layer mobility support which is not in the enabled using a higher layer mobility support which is not in the
scope of this document. 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 has IP1 -- anchored to a previous access router AR1 in network Net1 --
terminated before the MN moves to a new network Net2. After moving has terminated before the MN moves to a new network Net2. After
to Net2, the MN uses the new IP prefix IP2 anchored to a new access moving to Net2, the MN uses the new IP prefix IP2 -- anchored to a
router AR2 in network Net2 to start a new flow. The packets may then new access router AR2 in network Net2 -- to start a new flow.
be forwarded without requiring IP layer mobility support. Packets may then be forwarded without requiring IP layer mobility
support.
An example call flow is outlined in Figure 4. MN attaches to a An example call flow is outlined in Figure 4. A MN attaches to AR1,
network and AR1 sends a router advertisement (RA) including which sends a router advertisement (RA) including information about
information about the prefix assigned to MN, from which MN configures the prefix assigned to MN, from which MN configures an IP address
the IP address to use (IP1). This address is used for new (IP1). This address is used for new communications, for example with
communications, for example with a correspondent node (CN). If the a correspondent node (CN). If the MN moves to a new network and
MN moves to a new network and attaches to AR2, the process is attaches to AR2, the process is repeated (MN obtains a new IP
repeated (MN obtains a new IP address, IP2, from AR2). Since the IP address, IP2, from AR2). Since the IP address (IP1) configured at
address (IP1) configured at the previously visited network is not the previously visited network is not valid at the current attachment
valid at the current attachment point, any existing flows have to be point, and any existing flows have to be reestablished using IP2.
reestablished using IP2.
MN AR1 AR2 CN MN AR1 AR2 CN
|MN attaches to AR1: | | | |MN attaches to AR1: | | |
|acquire 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 | |
| | | | | | | |
|<-Flow(IP1,IPcn,...)-+------------------------------------------>| |<-Flow(IP1,IPcn,...)-+------------------------------------------>|
| | | | | | | |
|MN detaches from AR1 | | | |MN detaches from AR1 | | |
skipping to change at page 10, line 47 skipping to change at page 10, line 47
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
initial anchor remains the anchor and forwards traffic to a new initial anchor remains the anchor and forwards traffic to a new
locator in the new network, and (ii) the mobility anchor (data plane locator in the new network, and (ii) 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. The latter enables optimized routes but requires some data prefix. The latter enables optimized routes but requires some data
plane node that enforces rules for traffic indirection. Next, we plane node that enforces rules for traffic indirection. Next, we
focus on the first case. The second one is addressed in Section 4.3. focus on the first case. The second one is addressed in Section 4.3.
Mobility support can be provided by using mobility management methods Mobility support can be provided by using mobility management
such as ([Paper-Distributed.Mobility], methods, such as the several approaches surveyed in the academic
papers ([Paper-Distributed.Mobility],
[Paper-Distributed.Mobility.PMIP] and [Paper-Distributed.Mobility.PMIP] and
[Paper-Distributed.Mobility.Review]). After moving, a certain MN's [Paper-Distributed.Mobility.Review]). After moving, a certain MN's
traffic flow may continue using the IP prefix from the prior network traffic flow may continue using the IP prefix from the prior network
of attachment. Yet some time later, the user application for the of attachment. Yet, some time later, the application generating this
flow may be closed. If the application is started again, the new traffic flow may be closed. If the application is started again, the
flow may not need to use the prior network's IP address to avoid 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 having to invoke IP mobility support. This may be the case where a
dynamic IP prefix/address rather than a permanent one is used. The dynamic IP prefix/address, rather than a permanent one, is used.
flow may then use the new IP prefix in the network where the flow is Packets belonging to this flow may then use the new IP prefix (the
being initiated. Routing is again kept simpler without employing IP one allocated in the network where the flow is being initiated).
mobility and will remain so as long as the MN which is now in the new Routing is again kept simpler without employing IP mobility and will
network has not moved again and left to another new network. remain so as long as the MN which is now in the new network does not
move again to another network.
MN AR1 AR2 CN MN AR1 AR2 CN
|MN attaches to AR1: | | | |MN attaches to AR1: | | |
|acquire 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 | |
| | | | | | | |
|<-Flow(IP1,IPcn,...)-+------------------------------------------>| |<-Flow(IP1,IPcn,...)-+------------------------------------------>|
| | | | | | | |
|MN detach from AR1 | | | |MN detaches from AR1 | | |
|MN attach to AR2 | | | |MN attaches to AR2 | | |
| | | | | | | |
|--RS------------------------------>| | |--RS------------------------------>| |
IP mobility support such as that described in next sub-section (some IP mobility support solution)
|<--------------RA(IP2,IP1)---------| | |<--------------RA(IP2,IP1)---------| |
| | | | | | | |
| +<-Flow(IP1,IPcn,...)---------------------->| | +<-Flow(IP1,IPcn,...)---------------------->|
| +<===========>+ | | +<===========>+ |
|<-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 | |
skipping to change at page 12, line 15 skipping to change at page 12, line 17
to AR1 per default routing). The LM and FM functions are implemented to AR1 per default routing). The LM and FM functions are implemented
as shown in Figure 6. 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 at 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 |
+---------------+ +---------------+ +---------------+ +---------------+
+...............+ +---------------+ +...............+ +---------------+
.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 prefix 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, 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 rules for traffic indirection. node that enforces rules for 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. Here the anchoring of the IP flow as the MN moves to a new network. Here the anchoring of the IP
address of the flow is in the home network of the flow, which is not address of the flow is in the home network of the flow (i.e.,
in the current network of attachment. A centralized mobility different from the current network of attachment). A centralized
management mechanism may employ indirection from the anchor in the mobility management mechanism may employ indirection from the anchor
home network to the current network of attachment. Yet it may be in the home network to the current network of attachment. Yet it may
difficult to avoid unnecessarily long route when the route between be difficult to avoid using an unnecessarily long route (when the
the MN and the CN via the anchor in the home network is significantly route between the MN and the CN via the anchor in the home network is
longer than the direct route between them. An alternative is to significantly longer than the direct route between them). An
switch the IP prefix/address anchoring to the new network. alternative is to move the IP prefix/address anchoring to the new
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. Here the LM and FM functions in Figure 1 prefix/address of the flow. Here the LM and FM functions in Figure 1
in Section 3.1 are implemented as shown in Figure 7. in Section 3.1 are implemented as shown in Figure 7.
Net1 Net2 Net1 Net2
+---------------+ +---------------+
|AR1 | |AR2 |
+---------------+ +---------------+
|CPA: | |CPA: |
|LM:IP1 at IPa1 | |LM:IP1 at IPa2 | +---------------+ +---------------+
| changes to | | | |AR1 | |AR2 |
| IP1 at IPa2 | | | +---------------+ +---------------+
|---------------| |---------------| |CPA: | |CPA: |
|DPA(IPa1): | IP1 anchoring is effectively moved|DPA(IPa2): | |LM:IP1 at IPa1 | |LM:IP1 at IPa2 |
|anchored IP1 | =======> |anchors IP2,IP1| | 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) | .MN(IP1) . MN moves |MN(IP2,IP1) |
.flow(IP1,...) . =======> |flow(IP1,...) | .flow(IP1,...) . =======> |flow(IP1,...) |
+...............+ +---------------+ +...............+ +---------------+
Figure 7: Anchor mobility Figure 7: Anchor mobility
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 presents some scalability concerns and protocol, but such a solution may present some scalability concerns
its applicability is typically limited to small networks. 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]. When a mobile associates with an anchor
the anchor injects the mobile's prefix into the global routing
system. If the mobile moves to a new anchor, the old anchor
withdraws the /64 and the new anchor injects it instead.
5. Security Considerations 5. Security Considerations
Security protocols and mechanisms are employed to secure the network Security protocols and mechanisms are employed to secure the network
and to make continuous security improvements, and a DMM solution is and to make continuous security improvements, and a DMM solution is
required to support them [RFC7333]. required to support them [RFC7333].
In a DMM deployment [I-D.ietf-dmm-deployment-models] various attacks In a DMM deployment [I-D.ietf-dmm-deployment-models] various attacks
such as impersonation, denial of service, man-in-the-middle attacks such as impersonation, denial of service, man-in-the-middle attacks
need to be prevented. need to be prevented.
6. IANA Considerations 6. IANA Considerations
This document presents no IANA considerations. This document presents no IANA considerations.
7. Contributors 7. Contributors
Alexandre Petrescu and Fred L. Templin had contributed to earlier Alexandre Petrescu and Fred Templin had contributed to earlier
versions of this document regarding distributed anchoring for versions of this document regarding distributed anchoring for
hierarchical network and for network mobility, although these hierarchical network and for network mobility, although these
extensions were removed to keep the document within reasonable extensions were removed to keep the document within reasonable
length. length.
This document has benefited from other work on mobility support in This document has benefited from other work on mobility support in
SDN network, on providing mobility support only when needed, and on SDN network, on providing mobility support only when needed, and on
mobility support in enterprise network. These works have been mobility support in enterprise network. These works have been
referenced. While some of these authors have taken the work to referenced. While some of these authors have taken the work to
jointly write this document, others have contributed at least jointly write this document, others have contributed at least
indirectly by writing these drafts. The latter include Philippe indirectly by writing these drafts. The latter include Philippe
Bertin, Dapeng Liu, Satoru Matushima, Pierrick Seite, Jouni Korhonen, Bertin, Dapeng Liu, Satoru Matushima, Pierrick Seite, Jouni Korhonen,
and Sri Gundavelli. and Sri Gundavelli.
Valuable comments have been received from John Kaippallimalil, Valuable comments have been received from John Kaippallimalil,
ChunShan Xiong, and Dapeng Liu. Dirk von Hugo, Byju Pularikkal, ChunShan Xiong, Dapeng Liu and Fred Templin. Dirk von Hugo, Byju
Pierrick Seite have generously provided careful review with helpful Pularikkal, Pierrick Seite have generously provided careful review
corrections and suggestions. Marco Liebsch and Lyle Bertz also with helpful corrections and suggestions. Marco Liebsch and Lyle
performed very detailed and helpful reviews of this document. Bertz also performed very detailed and helpful reviews of this
document.
8. References 8. References
8.1. Normative References 8.1. Normative References
[I-D.bernardos-dmm-pmipv6-dlif] [RFC3753] Manner, J., Ed. and M. Kojo, Ed., "Mobility Related
Bernardos, C., Oliva, A., Giust, F., Zuniga, J., and A. Terminology", RFC 3753, DOI 10.17487/RFC3753, June 2004,
Mourad, "Proxy Mobile IPv6 extensions for Distributed <https://www.rfc-editor.org/info/rfc3753>.
Mobility Management", draft-bernardos-dmm-pmipv6-dlif-01
(work in progress), March 2018. [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>.
8.2. Informative References
[I-D.ietf-dmm-deployment-models] [I-D.ietf-dmm-deployment-models]
Gundavelli, S. and S. Jeon, "DMM Deployment Models and Gundavelli, S. and S. Jeon, "DMM Deployment Models and
Architectural Considerations", draft-ietf-dmm-deployment- Architectural Considerations", draft-ietf-dmm-deployment-
models-04 (work in progress), May 2018. models-04 (work in progress), May 2018.
[I-D.ietf-dmm-fpc-cpdp] [I-D.ietf-dmm-fpc-cpdp]
Matsushima, S., Bertz, L., Liebsch, M., Gundavelli, S., Matsushima, S., Bertz, L., Liebsch, M., Gundavelli, S.,
Moses, D., and C. Perkins, "Protocol for Forwarding Policy Moses, D., and C. Perkins, "Protocol for Forwarding Policy
Configuration (FPC) in DMM", draft-ietf-dmm-fpc-cpdp-12 Configuration (FPC) in DMM", draft-ietf-dmm-fpc-cpdp-12
(work in progress), June 2018. (work in progress), June 2018.
[I-D.ietf-dmm-ondemand-mobility] [I-D.ietf-dmm-ondemand-mobility]
Yegin, A., Moses, D., Kweon, K., Lee, J., Park, J., and S. Yegin, A., Moses, D., Kweon, K., Lee, J., Park, J., and S.
Jeon, "On Demand Mobility Management", draft-ietf-dmm- Jeon, "On Demand Mobility Management", draft-ietf-dmm-
ondemand-mobility-15 (work in progress), July 2018. ondemand-mobility-15 (work in progress), July 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-03 (work
in progress), October 2018.
[I-D.ietf-rtgwg-atn-bgp]
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-01 (work in progress), January 2019.
[I-D.matsushima-stateless-uplane-vepc] [I-D.matsushima-stateless-uplane-vepc]
Matsushima, S. and R. Wakikawa, "Stateless user-plane Matsushima, S. and R. Wakikawa, "Stateless user-plane
architecture for virtualized EPC (vEPC)", draft- architecture for virtualized EPC (vEPC)", draft-
matsushima-stateless-uplane-vepc-06 (work in progress), matsushima-stateless-uplane-vepc-06 (work in progress),
March 2016. March 2016.
[I-D.mccann-dmm-prefixcost] [I-D.mccann-dmm-prefixcost]
McCann, P. and J. Kaippallimalil, "Communicating Prefix McCann, P. and J. Kaippallimalil, "Communicating Prefix
Cost to Mobile Nodes", draft-mccann-dmm-prefixcost-03 Cost to Mobile Nodes", draft-mccann-dmm-prefixcost-03
(work in progress), April 2016. (work in progress), April 2016.
skipping to change at page 15, line 36 skipping to change at page 16, line 25
[I-D.seite-dmm-dma] [I-D.seite-dmm-dma]
Seite, P., Bertin, P., and J. Lee, "Distributed Mobility Seite, P., Bertin, P., and J. Lee, "Distributed Mobility
Anchoring", draft-seite-dmm-dma-07 (work in progress), Anchoring", draft-seite-dmm-dma-07 (work in progress),
February 2014. February 2014.
[I-D.yhkim-dmm-enhanced-anchoring] [I-D.yhkim-dmm-enhanced-anchoring]
Kim, Y. and S. Jeon, "Enhanced Mobility Anchoring in Kim, Y. and S. Jeon, "Enhanced Mobility Anchoring in
Distributed Mobility Management", draft-yhkim-dmm- Distributed Mobility Management", draft-yhkim-dmm-
enhanced-anchoring-05 (work in progress), July 2016. enhanced-anchoring-05 (work in progress), July 2016.
[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>.
[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>.
[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>.
8.2. Informative References
[Paper-Distributed.Mobility] [Paper-Distributed.Mobility]
Lee, J., Bonnin, J., Seite, P., and H. Chan, "Distributed Lee, J., Bonnin, J., Seite, P., and H. Chan, "Distributed
IP Mobility Management from the Perspective of the IETF: IP Mobility Management from the Perspective of the IETF:
Motivations, Requirements, Approaches, Comparison, and Motivations, Requirements, Approaches, Comparison, and
Challenges", IEEE Wireless Communications, October 2013. Challenges", IEEE Wireless Communications, October 2013.
[Paper-Distributed.Mobility.PMIP] [Paper-Distributed.Mobility.PMIP]
Chan, H., "Proxy Mobile IP with Distributed Mobility Chan, H., "Proxy Mobile IP with Distributed Mobility
Anchors", Proceedings of GlobeCom Workshop on Seamless Anchors", Proceedings of GlobeCom Workshop on Seamless
Wireless Mobility, December 2010. Wireless Mobility, December 2010.
[Paper-Distributed.Mobility.Review] [Paper-Distributed.Mobility.Review]
Chan, H., Yokota, H., Xie, J., Seite, P., and D. Liu, Chan, H., Yokota, H., Xie, J., Seite, P., and D. Liu,
"Distributed and Dynamic Mobility Management in Mobile "Distributed and Dynamic Mobility Management in Mobile
Internet: Current Approaches and Issues", February 2011. Internet: Current Approaches and Issues", February 2011.
Authors' Addresses [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>.
Authors' Addresses
H. Anthony Chan (editor) H. Anthony Chan (editor)
Huawei Technologies Huawei Technologies
5340 Legacy Dr. Building 3 5340 Legacy Dr. Building 3
Plano, TX 75024 Plano, TX 75024
USA USA
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 P. R. China
Email: weixinpeng@huawei.com Email: weixinpeng@huawei.com
Jong-Hyouk Lee Jong-Hyouk Lee
Sangmyung University Sangmyung University
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