DMM Practices and Gap Analysis
draft-zuniga-dmm-gap-analysis-01
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| Document | Type | Active Internet-Draft (individual) | |
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| Authors | Juan-Carlos Zúñiga , Carlos J. Bernardos , Telemaco Melia | ||
| Last updated | 2012-07-16 | ||
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draft-zuniga-dmm-gap-analysis-01
DMM WG JC. Zuniga
Internet-Draft InterDigital
Intended status: Informational CJ. Bernardos
Expires: January 17, 2013 UC3M
T. Melia
Alcatel-Lucent
July 16, 2012
DMM Practices and Gap Analysis
draft-zuniga-dmm-gap-analysis-01
Abstract
This document describes practices for the deployment of existing
mobility protocols in a distributed mobility management environment,
and identifies the limitations in the current practices with respect
to providing the expected functionality.
The practices and gap analysis is performed for IP-based mobility
protocols, dividing them into two main solution families: client- and
network-based.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on January 17, 2013.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
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publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Practices: deployment of existing solutions in a DMM
environment . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Client-based mobility . . . . . . . . . . . . . . . . . . 4
2.1.1. Mobile IPv6 / NEMO B.S. . . . . . . . . . . . . . . . 5
2.1.2. Mobile IPv6 Route Optimization . . . . . . . . . . . . 6
2.1.3. Hierarchical Mobile IPv6 . . . . . . . . . . . . . . . 8
2.1.4. Home Agent switch . . . . . . . . . . . . . . . . . . 9
2.1.5. Flow Mobility . . . . . . . . . . . . . . . . . . . . 9
2.1.6. Source Address selection API . . . . . . . . . . . . . 10
2.2. Network-based mobility . . . . . . . . . . . . . . . . . . 10
2.2.1. Proxy Mobile IPv6 . . . . . . . . . . . . . . . . . . 11
2.2.2. Local Routing . . . . . . . . . . . . . . . . . . . . 12
2.2.3. LMA runtime assignment . . . . . . . . . . . . . . . . 12
2.2.4. Source Address Selection . . . . . . . . . . . . . . . 13
2.2.5. Multihoming in PMIPv6 (as per RFC 5213) . . . . . . . 13
3. Gap Analysis: limitations in current practices . . . . . . . . 14
3.1. Client-based mobility . . . . . . . . . . . . . . . . . . 14
3.1.1. REQ1: Distributed deployment . . . . . . . . . . . . . 14
3.1.2. REQ2: Transparency to Upper Layers when needed . . . . 15
3.1.3. REQ3: IPv6 deployment . . . . . . . . . . . . . . . . 15
3.1.4. REQ4: Compatibility . . . . . . . . . . . . . . . . . 16
3.1.5. REQ5: Existing mobility protocols . . . . . . . . . . 16
3.1.6. REQ6: Security considerations . . . . . . . . . . . . 17
3.2. Network-based mobility . . . . . . . . . . . . . . . . . . 17
3.2.1. REQ1: Distributed deployment . . . . . . . . . . . . . 17
3.2.2. REQ2: Transparency to Upper Layers when needed . . . . 18
3.2.3. REQ3: IPv6 deployment . . . . . . . . . . . . . . . . 18
3.2.4. REQ4: Compatibility . . . . . . . . . . . . . . . . . 19
3.2.5. REQ5: Existing mobility protocols . . . . . . . . . . 19
3.2.6. REQ6: Security considerations . . . . . . . . . . . . 19
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
5. Security Considerations . . . . . . . . . . . . . . . . . . . 19
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6.1. Normative References . . . . . . . . . . . . . . . . . . . 20
6.2. Informative References . . . . . . . . . . . . . . . . . . 21
Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22
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1. Introduction
The Distributed Mobility Management (DMM) approach aims at setting up
IP networks so that traffic is distributed in an optimal way and does
not rely on centrally deployed anchors to manage IP mobility
sessions.
A first step towards the definition of DMM solutions is the
definition of the problem of distributed mobility management and the
identification of the main requirements for a distributed mobility
management solution [I-D.ietf-dmm-requirements], which are summarized
below:
o REQ1: Distributed deployment. IP mobility, network access and
routing solutions provided by DMM must enable a distributed
deployment of mobility management of IP sessions so that the
traffic can be routed in an optimal manner without traversing
centrally deployed mobility anchors.
o REQ2: Transparency to Upper Layers when needed. The DMM solutions
must provide transparency above the IP layer when needed. Such
transparency is needed, when the mobile hosts or entire mobile
networks change their point of attachment to the Internet, for the
application flows that cannot cope with a change of IP address.
Otherwise the support to maintain a stable home IP address or
prefix during handover may be declined.
o REQ3: IPv6 deployment. The DMM solutions should target IPv6 as
primary deployment and should not be tailored specifically to
support IPv4, in particular in situations where private IPv4
addresses and/or NATs are used.
o REQ4: Compatibility. The DMM solution should be able to work
between trusted administrative domains when allowed by the
security measures deployed between these domains. Furthermore,
the DMM solution must be able to co-exist with existing network
deployment and end hosts so that the existing deployment can
continue to be supported. For example, depending on the
environment in which DMM is deployed, the DMM solutions may need
to be compatible with other existing mobility protocols that are
deployed in that environment or may need to be interoperable with
the network or the mobile hosts/routers that do not support the
DMM enabling protocol.
o REQ5: Existing mobility protocols. A DMM solution should first
consider reusing and extending the existing mobility protocols
before specifying new protocols.
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o REQ6: Security considerations. The protocol solutions for DMM
must consider security, for example authentication and
authorization mechanisms that allow a legitimate mobile host/
router to access to the DMM service, protection of signaling
messages of the protocol solutions in terms of authentication,
data integrity, and data confidentiality, opti-in or opt-out data
confidentiality to signaling messages depending on network
environments or user requirements.
We next first analyze existing practices of deployment of IP mobility
solutions in a DMM environment [I-D.perkins-dmm-matrix],
[I-D.patil-dmm-issues-and-approaches2dmm]. After that, a gap
analysis is conducted, identifying what can be achieved with existing
solutions and what is missing in order to meet the DMM requirements
identified in [I-D.ietf-dmm-requirements].
2. Practices: deployment of existing solutions in a DMM environment
This section documents practices for the deployment of existing
mobility protocols in a distributed mobility management (DMM)
environment. This analysis is limited in scope to existing IPv6-
based mobility protocols, such as Mobile IPv6 [RFC6275], NEMO Basic
Support Protocol [RFC3963], Proxy Mobile IPv6 [RFC5213], and their
extensions, such as Hierarchical Mobile IPv6 [RFC5380], Mobile IPv6
Fast Handovers [RFC5568] or Localized Routing for Proxy Mobile IPv6
[I-D.ietf-netext-pmip-lr], among others.
The section is divided in two parts: client-based and network-based
mobility.
2.1. Client-based mobility
Mobile IPv6 (MIPv6) [RFC6275] and its extension to support mobile
networks, the NEMO Basic Support protocol (NEMO B.S.) [RFC3963] are
the main client-based IP mobility protocols. They heavily rely on
the figure of the Home Agent (HA), a centralized anchor, to provide
mobile nodes (hosts and routers) with mobility support. We next
describe how Mobile IPv6/NEMO and several additional protocol
extensions can be deployed to meet some of the DMM requirements
[I-D.ietf-dmm-requirements].
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2.1.1. Mobile IPv6 / NEMO B.S.
+-----+ +-----+
| CN1 | | CN2 |
+-----+ +-----+
| |
+------------------------------------------------+
( )
( ------- ------- )
( | HA1 | MN1 operator's | HA2 | )
( ------- core ------- )
( )
+------------------------------------------------+
/ | | \
/ | | \
/ | | \
/ | | \
-+----- ---+--- - -+--- -----+-
| AR1 | | AR2 | | AR3 | | AR4 |
---+--- ---+--- ---+--- ---+---
| | | |
(o) (o) (o) (o)
x x
x x
x x
(o) (o)
| |
+--+--+ +--+--+
( anchored ) | MN1 | ( anchored ) | MN2 |
( at HA1 ) +-----+ ( at HA2 ) +-----+
Figure 1: Distributed operation of Mobile IPv6 / NEMO B.S.
Due to the heavy dependance on the home agent role, Mobile IPv6 and
NEMO B.S. plain vanilla protocols (i.e., without additional
extensions) cannot be easily deployed in a distributed fashion. One
approach would be to deploy several HAs (like in Figure 1, and assign
to each MN the one closest to its topological location [RFC4640],
[RFC5026], [RFC6611]. In the example shown in Figure 1, MN1 is
assigned HA1 (and a home address anchored by HA1), while MN2 is
assigned HA2. Note that current Mobile IPv6 / NEMO B.S.
specifications do not allow the use of multiple home agents by a
mobile node simultaneously, and therefore the benefits of this
deployment model shown here are limited. For example, if MN1 moves
and attaches to AR4, the path followed by data packets would be
suboptimal, as they have to traverse HA1, which is no longer close to
the topological attachment point of MN1.
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2.1.2. Mobile IPv6 Route Optimization
+-----+ +-----+
| CN1 | | CN2 |
+-----+ +-----+
| |
+------------------------------------------------+
( )
( ------- )
( | HA1 | MN1 operator's )
( ------- core )
( )
+------------------------------------------------+
/ |
/ |
/ |
/ |
-+----- ---+---
| AR1 | | AR2 |
---+--- ---+---
| |
(o) (o)
x
x MN1 AR2 HA1 CN1 CN2
x | | | | |
(o) |<-------+---------------->| | RO mode
| | | | | |
+--+--+ |<=======+=======>|<--------------->| BT mode
| MN1 | | | | | |
+-----+
Figure 2: Mobile IPv6 Route Optimization
One of the main goals of DMM is to avoid the suboptimal routing
caused by centralized anchoring. By default, Mobile IPv6 (and NEMO
B.S.) uses the so-called Bidirectional Tunnel (BT) mode, in which
data traffic is always encapsulated between the MN and its HA.
Mobile IPv6 also specifies the Route Optimization (RO) mode, which
allows the MN to update its current location on the CNs, and then use
the direct path between them An example is shown in Figure 2, in
which MN1 is using BT mode with CN2 and RO mode with CN1. Note that
this RO mode has several drawbacks:
o The RO mode is only supported by Mobile IPv6. There is no route
optimization support standardized for the NEMO B. S. protocol,
although there are many different solution proposed, mainly as
academic exercises.
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o The RO mode requires additional signaling, which adds some
protocol overhead.
o The signaling required to enable RO involves the home agent, and
it is repeated periodically because of security reasons [RFC4225].
This basically means that the HA remains as single point of
failure, because the Mobile IPv6 RO mode does not mean HA-less
operation.
o The RO mode requires additional support on the correspondent node
(CN).
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2.1.3. Hierarchical Mobile IPv6
+-----+ +-----+
| CN1 | | CN2 |
+-----+ +-----+
| |
+------------------------------------------------+
( )
( ------- )
( | HA1 | MN1 operator's )
( ------- core )
( )
+------------------------------------------------+
/ | \
/ | \
/ | \
/ | \
--+----- ---+---- +--+----
| MAP1 | | MAP2 | | MAP3 |
---+---- ---+---- ---+----
/ \ / \ / \
/ \ / \ / \
/ \ / \ / \
--+-- --+-- --+-- --+-- --+-- --+--
|AR1| |AR2| |AR3| |AR4| |AR5| |AR6|
----- ----- ----- ----- ----- -----
|
(o)
x
x MN1 AR2 MAP1 HA1 CN1 CN2
x | | | | | |
(o) |<=====+======+======>+----->| |
| | | | | | |
+--+--+ |<=====+=====>+<------------------->|
| MN1 | | | | | | |
+-----+
Figure 3: Mobile IPv6 Route Optimization
Hierarchical Mobile IPv6 (HMIPv6) [RFC5380] allows reducing the
amount of mobility signaling as well as the overall handover
performance of Mobile IPv6, by introducing a new hierarchy level to
handle local mobility. The Mobility Anchor Point (MAP) entity is
introduced as a local mobility handling node deployed closer to the
mobile node.
When HMIPv6 is used, the MN two different temporal addresses: the
Regional Care-of Address (RCoA) and the Local Care-of Address (LCoA).
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The RCoA is anchored at one MAP, that plays the role of local home
agent, while the LCoA is anchored at the access router level. The
mobile node used the RCoA as the CoA signaled to its home agent.
Therefore, while roaming within a local domain handled by the same
MAP, the mobile node does not need to update its home agent (i.e.,
the mobile node does not change RCoA).
The use of HMIPv6 allows some certain route optimization, as a mobile
node may decide to directly use the RCoA as source address for a
communication with a given correspondent node, if the MN does not
expect to move outside the local domain during the lifetime of the
communication. This can be seen as a potential DMM mode of
operation. In the example shown in Figure 3, MN1 is using its global
HoA to communicate with CN1, while it is using its RCoA to
communicate with CN2.
Additionally, a local domain might have several MAPs deployed,
enabling different kind of HMIPv6 deployments (e.g., flat and
distributed). HMIPv6 specification supports a flexible selection of
the MAP (e.g., based on the distance between the MN and the MAP,
taking into consideration the expected mobility pattern of the MN,
etc.).
2.1.4. Home Agent switch
The Home Agent switch specification [RFC5142] defines a new mobility
header for signaling a mobile node that it should acquire a new home
agent. Although the purposes of this specification do not include
the case of changing the mobile node's home address, as that might
imply loss of connectivity for ongoing connections, it could be used
to force the change of home agent in those situations where there are
no active sessions running that cannot cope themselves with a change
of home address.
2.1.5. Flow Mobility
There exist different protocols meant to support flow mobility with
Mobile IPv6, namely the multiple care-of address registration
[RFC5648], the flow bindings in Mobile IPv6 and NEMO B.S. [RFC6089]
and the traffic selectors for flow bindings [RFC6088]. The use of
these extensions allows a mobile node to associate different flows
with different care-of addresses that the mobile owns at a given
time. This could also be used, combined with the route optimization
support, to improve the paths followed by data packets.
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2.1.6. Source Address selection API
The IPv6 socket API for source address selection [RFC5014], [RFC3484]
can be used by an application running on a mobile node to express its
preference of using a home address or a care-of address in a given
connection. This allows, for example, that an application which can
survive an IP address change to always prefer the use of a care-of
address. Similarly, and as mentioned in [RFC6275], a mobile node can
also prefer the use of a care-of address for sessions that are going
to finish before the mobile node hands off to a different attachment
point (e.g., short-lived connections like DNS dialogs).
2.2. Network-based mobility
Proxy Mobile IPv6 (PMIPv6) [RFC5213] and GPRS Tunneling Protocol
(GTP) [3GPP.29.060] are the main network-based IP mobility protocols.
PMIPv6 relies on the figure of the Local Mobility Anchor (LMA) to
provide mobile nodes with mobility support, without requiring the
involvement of the mobile nodes, and supplying the required
functionality by the Mobile Access Gateway (MAG). We next describe
how PMIPv6 and several additional protocol extensions can be deployed
to meet some of the DMM requirements [I-D.ietf-dmm-requirements].
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2.2.1. Proxy Mobile IPv6
+-----+ +-----+
| CN1 | | CN2 |
+-----+ +-----+
| |
+------------------------------------------------+
( )
( -------- -------- )
( | LMA1 | MN1 operator's | LMA2 | )
( -------- core -------- )
( )
+------------------------------------------------+
/ | | \
/ | | \
/ | | \
/ | | \
--+----- ----+--- ---+---- -----+--
| MAG1 | | MAG2 | | MAG3 | | MAG4 |
---+---- ----+--- ---+---- ---+----
| | | |
(o) (o) (o) (o)
x x
x x
x x
(o) (o)
| |
+--+--+ +--+--+
( anchored ) | MN1 | ( anchored ) | MN2 |
( at LMA1 ) +-----+ ( at LMA2 ) +-----+
Figure 4: Distributed operation of Proxy Mobile IPv6
As with Mobile IPv6, plain Proxy Mobile IPv6 operation cannot be
easily decentralized. One simple, but still suboptimal, approach
would be to deploy several local mobility anchors and use a
topological position based assignment to attaching mobile nodes (an
example is shown in Figure 4. This assignment can be static or
dynamic (as described in Section 2.2.3. The main advantage of this
simple approach is that the IP address anchor (i.e., the LMA) is
placed close to the mobile node, and therefore resulting paths are
close-to-optimal. On the other hand, as soon as the mobile node
moves, the resulting path starts to deviate from the optimal one,
unless an inter-LMA mobility protocol is in place (which is missing
today).
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2.2.2. Local Routing
[I-D.ietf-netext-pmip-lr] enables optimal routing in Proxy Mobile
IPv6 in three cases: two MNs attached to the same MAG and LMA, two
MNs attached to different MAGs but same LMA and two MNs attached to
the same MAG with different LMAs. In these three cases, data traffic
between two mobile nodes does not traverse the LMA(s), thus providing
some form of distribution, since the traffic is locally router at the
edge.
The main disadvantage of this approach is that it only tackles the
MN-to-MN communication scenario, and only under certain
circumstances.
In the context of 3GPP the closest analogy is the use of the X2
interface between two eNBs to directly exchange data traffic during
handover procedures. 3GPP does not foresee the use of local routing
at any other point of the network given the structure of the EPS
bearer model.
2.2.3. LMA runtime assignment
[RFC6463] specifies a runtime local mobility anchor assignment
functionality and corresponding mobility options for Proxy Mobile
IPv6. This runtime local mobility anchor assignment takes place
during a Proxy Binding Update and a Proxy Binding Acknowledgment
message exchange between a mobile access gateway and a local mobility
anchor. While this mechanism mainly aims for load-balancing
purposes, it can also be used to select an optimal LMA from a point
of view of routing. If properly complemented by an inter-LMA
mobility protocol, it could also be used as part of a global DMM
solution. Even without that solution, a runtime LMA assignment can
be used to change the assigned LMA of an MN, for example when no
session is alive (or when those running can survive an IP address
change).
In the context of 3GPP network similar considerations have been
discussed with respect to SIPTO above the RAN or at the macro. When
a MN is allowed to get SIPTO service a geographically close P-GW is
selected during connection time. That is, upon establishment of the
PDN connection, the MN is configured with an IP address belonging to
an optimal P-GW from a routing point of view. The drawback is that
if the MN moves out of the region covered by that P-GW it will need
to disconnect from the network and reconnect again since no seamless
session continuity is provided. In this sense applications that do
not survive and IP address change will result in an unpredictable
behavior.
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2.2.4. Source Address Selection
Also in the context of network based mobility source address
selection API can be considered as a mean to achieve better routing
(or using different anchors) and similar considerations of section
2.1.6 apply here. For instance a MN connected to a PMIPv6 domain
could attach two different wireless network interfaces to two
different MAGs, hence configuring a different set of HNPs on both
interfaces (potentially combining both IPv4 and IPv6). Based on
application requirements or operator's policies the connection
manager logic could instruct the IP stack on the MN to route selected
traffic on a specific wireless interface. It should be noted that
source address selection mostly provides a better routing but not
session continuity in case a session should be anchored and a
different LMA.
In the context of 3GPP networks two ongoing study items are currently
addressing the issue of selecting a wireless interface or an IP
address for a specific application. The study item DIDA (Data
IDentification in ANDSF) is addressing the need to map an application
ID to a specific wireless interface, while the study item OPIIS
(Operator Policies for IP Interface Selection) is addressing the need
of selecting the right APN for a given application. Taking into
account that there is a one to one link between APN and PDN
connection (IP address) the second study item clearly addresses from
a 3GPP perspective the same problem space as RFC 3484.
2.2.5. Multihoming in PMIPv6 (as per RFC 5213)
PMIPv6 provides some multihoming support. RFC 5213 defines that the
LMA can maintain one mobility session per attached interface and that
upon handover the full set of HNPs can be moved to another interface
in case of inter-technology handover (MAGs providing different
wireless access technology) or maintained on the same interface in
case of intra-technology handover (MAGs providing the same wireless
access technology). A MN can also attach (as described in section
2.2.4) two different interfaces to the PMIPv6 domain, hence resulting
in a multihomed device being able to send/receive traffic
sequentially or simultaneously from both network interfaces. [REF to
flow mob draft] extends the base RFC5213 capabilities in the sense
that a mobility session can now be shared across two different access
networks. It derives that a selected flow could be routed through
different paths hence achieving some sort of better routing. Yet all
the traffic is anchored to centralized anchor points.
In the context of 3GPP networks the MAPCON feature addresses the use
of multiple PDN connections, hence the use of multiple wireless
interfaces either sequentially or simultaneously.
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3. Gap Analysis: limitations in current practices
This section identifies the limitations in the current practices
(documented in Section 2) with respect to the requirements listed in
[I-D.ietf-dmm-requirements].
The section is also divided in two parts: client-based and network-
based mobility. Each section analyzes how well the requirements
listed in [I-D.ietf-dmm-requirements] are covered/met by the current
practices, highlighting existing limitations and gaps.
The remaining of this section will be provided in a future version of
this document.
3.1. Client-based mobility
3.1.1. REQ1: Distributed deployment
MIPv6 / NEMO B. S. A careful home agent deployment and policy
configuration of the Mobile IPv6 / NEMO B.S. protocols can achieve
some distribution. However, as soon as the mobile node moves and
changes its initial attachment point, the anchors are no longer
placed optimally, incurring in sub-optimal routes. If the mobile
node is not expected to move within a limited area, this
configuration might be considered sufficient. Otherwise,
additional mechanisms to support dynamic anchoring would be
needed.
Mobile IPv6 RO The use of route optimization support enables a
close-to anchor-less operation, which effectively can be
considered as a fully distributed configuration. However, as
explained before in this document, the home agent is still used
for the signaling and therefore remains as a critical centralized
component. Additionally, there is no RO support for network
mobility standardized.
HMIPv6 The use of hierarchical mobile IPv6 can be seen as a step
forward compared to a careful deployment of multiple home agents
and its proper configuration, as it allows a mobile node to roam
within a local domain, reducing the handover latency as well as
the signaling overhead. If used together with mobile IPv6,
traffic still has to traverse the centralized home agent, and
therefore no distributed operation is achieved.
HA switch The home agent switch specification can be used to enable
obtaining more benefits from a multiple-HA deployment, as the
mobile node could be instructed to switch to a closer home agent.
This switch can only performed without packet connectivity loss,
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if done at periods of time in which the mobile node does not have
any active connection running, and therefore the change of home
address would require sessions reestablishment.
Flow mobility Previous considerations could also apply here, being
the scenario extended by the use of multiple attached interfaces.
SA selection API The use of proper source address selection
decisions, enabled by smart connection managers, or mobility aware
applications using a selection API, would allow to benefit the
most from deployments exhibiting multiple anchors.
3.1.2. REQ2: Transparency to Upper Layers when needed
MIPv6 / NEMO B. S. As a mobility protocol is used, the solution is
transparent to the upper layers. However, as described before,
this transparency comes with the cost of suboptimal routes if the
mobile nodes moves away from its initial attachment point.
Mobile IPv6 RO The use of the route optimization support is
transparent to the upper layers.
HMIPv6 The use of HMIPv6 is transparent to the upper layers.
HA switch The use of the home agent switch functionality is not
transparent to the upper layers, as a change of home agent
normally implies a change of home address. Therefore, it is only
recommended to switch home agent when there is no active session
running on the mobile node.
Flow mobility The use of flow mobility mechanisms is transparent to
the upper layers.
SA selection API The use of an intelligent source address mechanisms
is transparent to the upper layers if performed by the connection
manager. However if the selection is performed by the
applications themselves, via the use of the API, then applications
have to be mobility-aware.
3.1.3. REQ3: IPv6 deployment
MIPv6 / NEMO B. S. Mobile IPv6 / NEMO B.S. protocols primarily
support IPv6, although there are some extensions defined to also
offer some IPv4 support.
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Mobile IPv6 RO Route optimization only supports IPv6.
HMIPv6 HMIPv6 is only defined for IPv6.
HA switch The home agent switch specification supports only IPv6,
although the use of the defined mechanisms to support dual stack
IPv4/IPv6 mobile nodes would also enable some IPv4 support in this
case.
Flow mobility Flow mobility is only defined for IPv6.
SA selection API The use of source address selection mechanisms
support both IPv6 and IPv4.
3.1.4. REQ4: Compatibility
MIPv6 / NEMO B. S. This approach would be compatible with other
protocols and work between trusted administrative domains,
although as described before its operation would not provide the
benefits of a fully distributed mechanism.
Mobile IPv6 RO This approach would be compatible with other
protocols and work between trusted administrative domains, as long
as mobile IPv6 is allowed. However, as highlighted before, mobile
IPv6 route optimization requires specific support on the
correspondent nodes.
HMIPv6 HMIPv6 is compatible with other protocols.
HA switch This approach would be compatible with other protocols and
work between trusted administrative domains.
Flow mobility This approach would be compatible with other protocols
and work between trusted administrative domains.
SA selection API This approach has no impact in terms of
compatibility or use between trusted administrative domains.
3.1.5. REQ5: Existing mobility protocols
MIPv6 / NEMO B. S. This approach is based on existing protocols
[RFC6275] and [RFC3963].
Mobile IPv6 RO This approach is based on existing protocol
[RFC6275].
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HMIPv6 This approach is based on existing protocol [RFC5380].
HA switch This approach is based on existing protocol [RFC5142].
Flow mobility This approach is based on existing protocols
[RFC5648], [RFC6089] and [RFC6088].
SA selection API This approach is based on existing protocols
[RFC3484] and [RFC5014].
3.1.6. REQ6: Security considerations
MIPv6 / NEMO B. S. This approach include security considerations.
Mobile IPv6 RO This approach include security considerations.
HMIPv6 This approach include security considerations.
HA switch This approach include security considerations.
Flow mobility This approach include security considerations.
SA selection API This approach does not have security issues.
3.2. Network-based mobility
3.2.1. REQ1: Distributed deployment
Local Routing As mentioned it enables optimal routing in three
cases: the LMA manages the traffic of two mobile nodes connected
to teh same MAG, the LMA manages the traffic of two mobile nodes
connected to different MAGs, the MAG manages the traffic of two
mobile nodes connected to different LMAs. LR does not consider
the case where the traffic should be optimized considering
different MAGs and different LMAs. Inter LMA communication is not
in scope. LR only enables better routing and does not consider
the distribution of mobility anchors as such.
LMA Runtime Assignment The LMA runtime assignment is used to
allocate an optimal LMA mostly for load balancing purposes (for
instance in scenarios where LMAs run in datacenter alike
infrastructure). It can be used to allocate a different LMA based
on other policies such as routing although is not clear how the
technology can be used to achieve distributed mobility management,
especially considering scalability issues.
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Source Address Selection It can help in selecting a given IP source
address although the specs have many limitations (for instance
prefer IPv6 over IPv4, prefer HoA instead of CoA) and the socket
extensions [RFC5014] require changes in the node. This solution
alone is not sufficient to achieve anchors distribution in case of
session continuity requirements.
Multihoming in PMIPv6 As summarized in the previous section a single
mobility session belongs to a single LMA (at the most the same
mobility session is shared across two access networks). As of
today there is no possibility to distribute anchors and to move
the session between different LMAs.
3.2.2. REQ2: Transparency to Upper Layers when needed
Local Routing During HO the standard mechanisms are used. In this
sense if there is a MAG change while LR is enabled signaling is
exchanged to inform the target MAG that upon handover LR should be
re-established. The inter LMA case is not supported. For this
solution the mobility context is always up, all the traffic
receive seamless service.
LMA Runtime Assignment Seamless support is provided as per RFC 5213.
For this solution the mobility context is always up, all the
traffic receive seamless service.
Source Address Selection No seamless support is provided since it
requires solutions such as IP flow mobility for PMIPv6.
Multihoming in PMIPv6 Seamless support falls back to standard PMIPv6
operations extended for IP flow mobility support. For this
solution the mobility context is always up, all the traffic
receive seamless service.
3.2.3. REQ3: IPv6 deployment
Local Routing It supports both IPv4 and IPv6.
LMA Runtime Assignment It supports both IPv4 and IPv6.
Source Address Selection It supports both IPv4 and IPv6.
Multihoming in PMIPv6 It supports both IPv4 and IPv6.
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3.2.4. REQ4: Compatibility
Local Routing Since it extends RFC 5213 compatibility with previous
technology is provided.
LMA Runtime Assignment Since it extends RFC 5213 compatibility with
previous technology is provided.
Source Address Selection To enable the full set of use cases
mentioned above extensions are required thus impacting the
landscape of mobile devices. The extensions should not impact the
network.
Multihoming in PMIPv6 Since it extends RFC 5213 compatibility is
provided.
3.2.5. REQ5: Existing mobility protocols
Local Routing It reuses RFC 5213.
LMA Runtime Assignment It reuses RFC 5213.
Source Address Selection This is terminal only.
Multihoming in PMIPv6 It reuses RFC 5213.
3.2.6. REQ6: Security considerations
Local Routing It reuses RFC 5213 as such same security
considerations apply.
LMA Runtime Assignment It reuses RFC 5213 as such same security
considerations apply.
Source Address Selection There is not signaling involved here.
Multihoming in PMIPv6 It reuses RFC 5213 as such same security
considerations apply.
4. IANA Considerations
No IANA considerations.
5. Security Considerations
TBD.
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6. References
6.1. Normative References
[RFC3484] Draves, R., "Default Address Selection for Internet
Protocol version 6 (IPv6)", RFC 3484, February 2003.
[RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P.
Thubert, "Network Mobility (NEMO) Basic Support Protocol",
RFC 3963, January 2005.
[RFC5026] Giaretta, G., Kempf, J., and V. Devarapalli, "Mobile IPv6
Bootstrapping in Split Scenario", RFC 5026, October 2007.
[RFC5142] Haley, B., Devarapalli, V., Deng, H., and J. Kempf,
"Mobility Header Home Agent Switch Message", RFC 5142,
January 2008.
[RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.
[RFC5380] Soliman, H., Castelluccia, C., ElMalki, K., and L.
Bellier, "Hierarchical Mobile IPv6 (HMIPv6) Mobility
Management", RFC 5380, October 2008.
[RFC5568] Koodli, R., "Mobile IPv6 Fast Handovers", RFC 5568,
July 2009.
[RFC5648] Wakikawa, R., Devarapalli, V., Tsirtsis, G., Ernst, T.,
and K. Nagami, "Multiple Care-of Addresses Registration",
RFC 5648, October 2009.
[RFC6088] Tsirtsis, G., Giarreta, G., Soliman, H., and N. Montavont,
"Traffic Selectors for Flow Bindings", RFC 6088,
January 2011.
[RFC6089] Tsirtsis, G., Soliman, H., Montavont, N., Giaretta, G.,
and K. Kuladinithi, "Flow Bindings in Mobile IPv6 and
Network Mobility (NEMO) Basic Support", RFC 6089,
January 2011.
[RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support
in IPv6", RFC 6275, July 2011.
[RFC6463] Korhonen, J., Gundavelli, S., Yokota, H., and X. Cui,
"Runtime Local Mobility Anchor (LMA) Assignment Support
for Proxy Mobile IPv6", RFC 6463, February 2012.
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[RFC6611] Chowdhury, K. and A. Yegin, "Mobile IPv6 (MIPv6)
Bootstrapping for the Integrated Scenario", RFC 6611,
May 2012.
6.2. Informative References
[3GPP.29.060]
3GPP, "General Packet Radio Service (GPRS); GPRS
Tunnelling Protocol (GTP) across the Gn and Gp interface",
3GPP TS 29.060 3.19.0, March 2004.
[I-D.ietf-dmm-requirements]
Chan, A., "Requirements of distributed mobility
management", draft-ietf-dmm-requirements-01 (work in
progress), July 2012.
[I-D.ietf-netext-pmip-lr]
Krishnan, S., Koodli, R., Loureiro, P., Wu, W., and A.
Dutta, "Localized Routing for Proxy Mobile IPv6",
draft-ietf-netext-pmip-lr-10 (work in progress), May 2012.
[I-D.patil-dmm-issues-and-approaches2dmm]
Patil, B., Williams, C., and J. Korhonen, "Approaches to
Distributed mobility management using Mobile IPv6 and its
extensions", draft-patil-dmm-issues-and-approaches2dmm-00
(work in progress), March 2012.
[I-D.perkins-dmm-matrix]
Perkins, C., Liu, D., and W. Luo, "DMM Comparison Matrix",
draft-perkins-dmm-matrix-03 (work in progress),
March 2012.
[RFC4225] Nikander, P., Arkko, J., Aura, T., Montenegro, G., and E.
Nordmark, "Mobile IP Version 6 Route Optimization Security
Design Background", RFC 4225, December 2005.
[RFC4640] Patel, A. and G. Giaretta, "Problem Statement for
bootstrapping Mobile IPv6 (MIPv6)", RFC 4640,
September 2006.
[RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6
Socket API for Source Address Selection", RFC 5014,
September 2007.
Appendix A. Acknowledgments
The work of Carlos J. Bernardos and Telemaco Melia has been partially
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supported by the European Community's Seventh Framework Programme
(FP7-ICT-2009-5) under grant agreement n. 258053 (MEDIEVAL project).
The work of Carlos J. Bernardos has also been partially supported by
the Ministry of Science and Innovation of Spain under the QUARTET
project (TIN2009-13992-C02-01).
Authors' Addresses
Juan Carlos Zuniga
InterDigital Communications, LLC
1000 Sherbrooke Street West, 10th floor
Montreal, Quebec H3A 3G4
Canada
Email: JuanCarlos.Zuniga@InterDigital.com
URI: http://www.InterDigital.com/
Carlos J. Bernardos
Universidad Carlos III de Madrid
Av. Universidad, 30
Leganes, Madrid 28911
Spain
Phone: +34 91624 6236
Email: cjbc@it.uc3m.es
URI: http://www.it.uc3m.es/cjbc/
Telemaco Melia
Alcatel-Lucent Bell Labs
Route de Villejust
Nozay, Ile de France 91620
France
Email: telemaco.melia@alcatel-lucent.com
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