draft-ietf-dmm-requirements-04.txt   draft-ietf-dmm-requirements-05.txt 
Network Working Group H. Chan (Ed.) Network Working Group H. Chan (Ed.)
Internet-Draft Huawei Technologies (more Internet-Draft Huawei Technologies (more
Intended status: Informational co-authors on P. 17) Intended status: Informational co-authors on P. 17)
Expires: November 9, 2013 D. Liu Expires: December 7, 2013 D. Liu
China Mobile China Mobile
P. Seite P. Seite
France Telecom - Orange Orange
H. Yokota H. Yokota
KDDI Lab KDDI Lab
J. Korhonen J. Korhonen
Nokia Siemens Networks Nokia Siemens Networks
May 8, 2013 June 5, 2013
Requirements for Distributed Mobility Management Requirements for Distributed Mobility Management
draft-ietf-dmm-requirements-04 draft-ietf-dmm-requirements-05
Abstract Abstract
This document defines the requirements for Distributed Mobility This document defines the requirements for Distributed Mobility
Management (DMM) in IPv6 deployments. The hierarchical structure in Management (DMM) in IPv6 deployments. The hierarchical structure in
traditional wireless networks has led to deployment models which are traditional wireless networks has led to deployment models which are
in practice centralized. Mobility management with logically in practice centralized. Mobility management with logically
centralized mobility anchoring in current mobile networks is prone to centralized mobility anchoring in current mobile networks is prone to
suboptimal routing and raises scalability issues. Such centralized suboptimal routing and raises scalability issues. Such centralized
functions can lead to single points of failure and inevitably functions can lead to single points of failure and inevitably
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network evolution, i.e., improve scalability, avoid single points of network evolution, i.e., improve scalability, avoid single points of
failure, enable transparent mobility support to upper layers only failure, enable transparent mobility support to upper layers only
when needed, and so on. Distributed mobility management must be when needed, and so on. Distributed mobility management must be
secure and may co-exist with existing network deployments and end secure and may co-exist with existing network deployments and end
hosts. hosts.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 RFC 2119
[RFC2119].
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 http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 9, 2013. This Internet-Draft will expire on December 7, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions used in this document . . . . . . . . . . . . . . 6 2. Conventions used in this document . . . . . . . . . . . . . . 6
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 6 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 6
3. Centralized versus distributed mobility management . . . . . . 7 3. Centralized versus distributed mobility management . . . . . . 6
3.1. Centralized mobility management . . . . . . . . . . . . . 7 3.1. Centralized mobility management . . . . . . . . . . . . . 7
3.2. Distributed mobility management . . . . . . . . . . . . . 8 3.2. Distributed mobility management . . . . . . . . . . . . . 8
4. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 9 4. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 9
5. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 11 5. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1. Distributed deployment . . . . . . . . . . . . . . . . . . 11 5.1. Distributed processing . . . . . . . . . . . . . . . . . . 11
5.2. Transparency to Upper Layers when needed . . . . . . . . . 11 5.2. Transparency to Upper Layers when needed . . . . . . . . . 11
5.3. IPv6 deployment . . . . . . . . . . . . . . . . . . . . . 12 5.3. IPv6 deployment . . . . . . . . . . . . . . . . . . . . . 12
5.4. Existing mobility protocols . . . . . . . . . . . . . . . 12 5.4. Existing mobility protocols . . . . . . . . . . . . . . . 12
5.5. Co-existence . . . . . . . . . . . . . . . . . . . . . . . 12 5.5. Co-existence . . . . . . . . . . . . . . . . . . . . . . . 12
5.6. Security considerations . . . . . . . . . . . . . . . . . 13 5.6. Security considerations . . . . . . . . . . . . . . . . . 13
5.7. Multicast considerations . . . . . . . . . . . . . . . . . 13 5.7. Multicast . . . . . . . . . . . . . . . . . . . . . . . . 14
6. Security Considerations . . . . . . . . . . . . . . . . . . . 14 6. Security Considerations . . . . . . . . . . . . . . . . . . . 14
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
8. Co-authors and Contributors . . . . . . . . . . . . . . . . . 14 8. Co-authors and Contributors . . . . . . . . . . . . . . . . . 15
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . . 14 9.1. Normative References . . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . . 14 9.2. Informative References . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction 1. Introduction
In the past decade a fair number of mobility protocols have been In the past decade a fair number of mobility protocols have been
standardized [RFC6275] [RFC5944] [RFC5380] [RFC6301] [RFC5213]. standardized [RFC6275] [RFC5944] [RFC5380] [RFC6301] [RFC5213].
Although the protocols differ in terms of functions and associated Although the protocols differ in terms of functions and associated
message formats, we can identify a few key common features: message formats, we can identify a few key common features:
o a centralized mobility anchor providing global reachability and an o a centralized mobility anchor providing global reachability and an
always-on experience to the user; always-on experience to the user;
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for multi-mode terminals (e.g. smartphones). for multi-mode terminals (e.g. smartphones).
The presence of the centralized mobility anchor allows a mobile node The presence of the centralized mobility anchor allows a mobile node
to remain reachable after it has moved to a different network. The to remain reachable after it has moved to a different network. The
anchor point, among other tasks, ensures connectivity by forwarding anchor point, among other tasks, ensures connectivity by forwarding
packets destined to, or sent from, the mobile node. In practice, packets destined to, or sent from, the mobile node. In practice,
most of the deployed architectures today have a small number of most of the deployed architectures today have a small number of
centralized anchors managing the traffic of millions of mobile nodes. centralized anchors managing the traffic of millions of mobile nodes.
Compared with a distributed approach, a centralized approach is Compared with a distributed approach, a centralized approach is
likely to have several issues or limitations affecting performance likely to have several issues or limitations affecting performance
and scalability, which require costly network dimensioning and and scalability, which require costly network engineering to resolve.
engineering to resolve.
To optimize handovers from the perspective of mobile nodes, the base To optimize handovers from the perspective of mobile nodes, the base
protocols have been extended to efficiently handle packet forwarding protocols have been extended to efficiently handle packet forwarding
between the previous and new points of attachment. These extensions between the previous and new points of attachment. These extensions
are necessary when applications have stringent requirements in terms are necessary when applications have stringent requirements in terms
of delay. Notions of localization and distribution of local agents of delay. Notions of localization and distribution of local agents
have been introduced to reduce signaling overhead [Paper- have been introduced to reduce signaling overhead at the centralized
Distributed.Centralized.Mobility]. Unfortunately, today we witness routing anchor point [Paper-Distributed.Centralized.Mobility].
difficulties in getting such protocols deployed, resulting in sub- Unfortunately, today we witness difficulties in getting such
optimal choices for the network operators. protocols deployed, resulting in sub-optimal choices for the network
operators.
Moreover, the availability of multiple-interface host and the Moreover, the availability of multiple-interface host and the
possibility of using several network interfaces simultaneously have possibility of using several network interfaces simultaneously have
motivated the development of even more protocol extensions to add motivated the development of even more protocol extensions to add
more capabilities to the mobility management protocol. In the end, more capabilities to the mobility management protocol. In the end,
deployment is further complicated with the multitude of extensions. deployment is further complicated with the multitude of extensions.
As an effective transport method for multimedia data delivery, IP As an effective transport method for multimedia data delivery, IP
multicast support, including optimizations, have been introduced but multicast support, including optimizations, have been introduced but
by "patching-up" procedure after completing the design of reference by "patching-up" procedure after completing the design of reference
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the user proximity into account within EPC [TS.29303]. These the user proximity into account within EPC [TS.29303]. These
mechanisms were not pursued in the past owing to charging and billing mechanisms were not pursued in the past owing to charging and billing
reasons. Assigning a gateway anchor node from a visited network in reasons. Assigning a gateway anchor node from a visited network in
roaming scenario has until recently been done and are limited to roaming scenario has until recently been done and are limited to
voice services only. Charging and billing require solutions beyond voice services only. Charging and billing require solutions beyond
the mobility protocol. the mobility protocol.
Both traffic offloading and CDN mechanisms could benefit from the Both traffic offloading and CDN mechanisms could benefit from the
development of mobile architectures with fewer levels of routing development of mobile architectures with fewer levels of routing
hierarchy introduced into the data path by the mobility management hierarchy introduced into the data path by the mobility management
system. This trend towards so-called "flat networks" is reinforced system. This trend towards so-called "flat networks" works best for
by a shift in user traffic behavior. In particular, there are direct direct communications among peers in the same geographical area.
communications among peers in the same geographical area.
Distributed mobility management in a truly flat mobile architecture Distributed mobility management in a truly flat mobile architecture
would anchor the traffic closer to the point of attachment of the would anchor the traffic closer to the point of attachment of the
user. user.
Today's mobile networks present service providers with new Today's mobile networks present service providers with new
challenges. Mobility patterns indicate that mobile nodes remain challenges. Mobility patterns indicate that mobile nodes often
attached to the same point of attachment for considerable periods of remain attached to the same point of attachment for considerable
time [Paper-Locating.User]. Specific IP mobility management support periods of time [Paper-Locating.User]. Specific IP mobility
is not required for applications that launch and complete their management support is not required for applications that launch and
sessions while the mobile node is connected to the same point of complete their sessions while the mobile node is connected to the
attachment. However, currently, IP mobility support is designed for same point of attachment. However, currently, IP mobility support is
always-on operation, maintaining all parameters of the context for designed for always-on operation, maintaining all parameters of the
each mobile subscriber for as long as they are connected to the context for each mobile subscriber for as long as they are connected
network. This can result in a waste of resources and unnecessary to the network. This can result in a waste of resources and
costs for the service provider. Infrequent node mobility coupled unnecessary costs for the service provider. Infrequent node mobility
with application intelligence suggest that mobility support could be coupled with application intelligence suggest that mobility support
provided selectively, thus reducing the amount of context maintained could be provided selectively, thus reducing the amount of context
in the network. maintained in the network.
The distributed mobility managemetn (DMM) charter addresses two The distributed mobility management (DMM) charter addresses two
complementary aspects of mobility management procedures: the complementary aspects of mobility management procedures: the
distribution of mobility anchors towards a more flat network and the distribution of mobility anchors towards a more flat network and the
dynamic activation/deactivation of mobility protocol support as an dynamic activation/deactivation of mobility protocol support as an
enabler to distributed mobility management. The former aims at enabler to distributed mobility management. The former aims at
positioning mobility anchors (e.g., HA, LMA) closer to the user; positioning mobility anchors (e.g., HA, LMA) closer to the user;
ideally, mobility agents could be collocated with the first-hop ideally, mobility agents could be collocated with the first-hop
router. The latter, facilitated by the distribution of mobility router. The latter, facilitated by the distribution of mobility
anchors, aims at identifying when mobility support must be activated anchors, aims at identifying when mobility support must be activated
and identifying sessions that do not require mobility management and identifying sessions that do not require mobility management
support -- thus reducing the amount of state information that must be support -- thus reducing the amount of state information that must be
maintained in various mobility agents of the mobile network. The key maintained in various mobility agents of the mobile network. The key
idea is that dynamic mobility management relaxes some of the idea is that dynamic mobility management relaxes some of the
constraints of previously-standardized mobility management solutions constraints of previously-standardized mobility management solutions
and, by doing so, it can avoid the unnecessary establishment of and, by doing so, it can avoid the unnecessary establishment of
mechanisms to forward traffic from an old to a new mobility anchor. mechanisms to forward traffic from an old to a new mobility anchor.
This document compares distributed mobility management with This document compares distributed mobility management with
centralized mobility management in Section 3. The problems that can centralized mobility management in Section 3. The problems that can
be addressed with DMM are summarized in Section 4. The requirements be addressed with DMM are summarized in Section 4. The mandatory
to address various problems are given in Section 5. Finally, requirements as well as the optional requirements are given in
security considerations are discussed in Section 6. Section 5. Finally, security considerations are discussed in Section
6.
The problem statement and the use cases [I-D.yokota-dmm-scenario] can The problem statement and the use cases [I-D.yokota-dmm-scenario] can
be found in [Paper-Distributed.Mobility.Review]. be found in [Paper-Distributed.Mobility.Review].
2. Conventions used in this document 2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL","SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2.1. Terminology 2.1. Terminology
All the general mobility-related terms and their acronyms used in All the general mobility-related terms and their acronyms used in
this document are to be interpreted as defined in the Mobile IPv6 this document are to be interpreted as defined in the Mobile IPv6
base specification [RFC6275], in the Proxy mobile IPv6 specification base specification [RFC6275], in the Proxy mobile IPv6 specification
[RFC5213], and in Mobility Related Terminology [RFC3753]. These [RFC5213], and in Mobility Related Terminology [RFC3753]. These
terms include the following: mobile node (MN), correspondent node terms include the following: mobile node (MN), correspondent node
(CN), and home agent (HA) as per [RFC6275]; local mobility anchor (CN), and home agent (HA) as per [RFC6275]; local mobility anchor
(LMA) and mobile access gateway (MAG) as per [RFC5213], and context (LMA) and mobile access gateway (MAG) as per [RFC5213], and context
as per [RFC3753]. as per [RFC3753].
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The next two subsections explain centralized and distributed mobility The next two subsections explain centralized and distributed mobility
management functions in the network. management functions in the network.
3.1. Centralized mobility management 3.1. Centralized mobility management
In centralized mobility management, the mapping information between In centralized mobility management, the mapping information between
the persistent node identifier and the locator IP address of a mobile the persistent node identifier and the locator IP address of a mobile
node (MN) is kept at a single mobility anchor. At the same time, node (MN) is kept at a single mobility anchor. At the same time,
packets destined to the MN are routed via this anchor. In other packets destined to the MN are routed via this anchor. In other
words, such mobility management systems are centralized in both the words, such mobility management systems are centralized in both the
control plane and the data plane. control plane and the data plane (mobile node IP traffic).
Many existing mobility management deployments make use of centralized Many existing mobility management deployments make use of centralized
mobility anchoring in a hierarchical network architecture, as shown mobility anchoring in a hierarchical network architecture, as shown
in Figure 1. Examples of such centralized mobility anchors are the in Figure 1. Examples of such centralized mobility anchors are the
home agent (HA) and local mobility anchor (LMA) in Mobile IPv6 home agent (HA) and local mobility anchor (LMA) in Mobile IPv6
[RFC6275] and Proxy Mobile IPv6 [RFC5213], respectively. Current [RFC6275] and Proxy Mobile IPv6 [RFC5213], respectively. Current
cellular networks such as the Third Generation Partnership Project cellular networks such as the Third Generation Partnership Project
(3GPP) GPRS networks, CDMA networks, and 3GPP Evolved Packet System (3GPP) GPRS networks, CDMA networks, and 3GPP Evolved Packet System
(EPS) networks employ centralized mobility management too. In (EPS) networks employ centralized mobility management too. In
particular, the Gateway GPRS Support Node (GGSN), Serving GPRS particular, the Gateway GPRS Support Node (GGSN), Serving GPRS
Support Node (SGSN) and Radio Network Controller (RNC) in the 3GPP Support Node (SGSN) and Radio Network Controller (RNC) in the 3GPP
GPRS hierarchical network, and the Packet Data Network Gateway (P-GW) GPRS hierarchical network, and the Packet Data Network Gateway (P-GW)
and Serving Gateway (S-GW) in the 3GPP EPS network, respectively, act and Serving Gateway (S-GW) in the 3GPP EPS network all act as anchors
as anchors in a hierarchy. in a hierarchy.
3G GPRS 3GPP EPS MIP/PMIP 3G GPRS 3GPP EPS MIP/PMIP
+------+ +------+ +------+ +------+ +------+ +------+
| GGSN | | P-GW | |HA/LMA| | GGSN | | P-GW | |HA/LMA|
+------+ +------+ +------+ +------+ +------+ +------+
/\ /\ /\ /\ /\ /\
/ \ / \ / \ / \ / \ / \
/ \ / \ / \ / \ / \ / \
/ \ / \ / \ / \ / \ / \
/ \ / \ / \ / \ / \ / \
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PS2: Divergence from other evolutionary trends in network PS2: Divergence from other evolutionary trends in network
architectures such as distribution of content delivery. architectures such as distribution of content delivery.
Centralized mobility management can become non-optimal with a Centralized mobility management can become non-optimal with a
flat network architecture. flat network architecture.
PS3: Low scalability of centralized tunnel management and mobility PS3: Low scalability of centralized tunnel management and mobility
context maintenance context maintenance
Setting up tunnels through a central anchor and maintaining Setting up tunnels through a central anchor and maintaining
mobility context for each MN requires more resources in a mobility context for each MN usually requires more concentrated
centralized design, thus reducing scalability. Distributing resources in a centralized design, thus reducing scalability.
the tunnel maintenance function and the mobility context Distributing the tunnel maintenance function and the mobility
maintenance function among different network entities with context maintenance function among different network entities
proper signaling protocol design can increase scalability. with proper signaling protocol design can increase scalability.
PS4: Single point of failure and attack PS4: Single point of failure and attack
Centralized anchoring designs may be more vulnerable to single Centralized anchoring designs may be more vulnerable to single
points of failures and attacks than a distributed system. The points of failures and attacks than a distributed system. The
impact of a successful attack on a system with centralized impact of a successful attack on a system with centralized
mobility management can be far greater as well. mobility management can be far greater as well.
PS5: Unnecessarily reserving resources to provide mobility support PS5: Unnecessarily reserving resources to provide mobility support
to nodes that do not need such support to nodes that do not need such support
IP mobility support is not always required, and not every IP mobility support is not always required, and not every
parameter of mobility context is always used. For example, parameter of mobility context is always used. For example,
some applications do not need a stable IP address during a some applications do not need a stable IP address during a
handover to maintain session continuity. Sometimes, the entire handover to maintain session continuity. Sometimes, the entire
application session runs while the terminal does not change the application session runs while the terminal does not change the
point of attachment. Besides, some sessions, e.g. SIP-based point of attachment. Besides, some sessions, e.g. SIP-based
sessions, can handle mobility at the application layer and sessions, can handle mobility at the application layer and
hence do not need IP mobility support; it is then more hence do not need IP mobility support; it is then more
efficient to deactivate IP mobility support for such sessions." efficient to deactivate IP mobility support for such sessions.
PS6: (Related problem) Mobility signaling overhead with peer-to-peer PS6: (Related problem) Mobility signaling overhead with peer-to-peer
communication communication
Wasting resources when mobility signaling (e.g., maintenance of Wasting resources when mobility signaling (e.g., maintenance of
the tunnel, keep alive signaling, etc.) is not turned off for the tunnel, keep alive signaling, etc.) is not turned off for
peer-to-peer communication. Peer-to-peer communications have peer-to-peer communication. Peer-to-peer communications have
particular traffic patterns that often do not benefit from particular traffic patterns that often do not benefit from
mobility support from the network. Thus, the associated mobility support from the network. Thus, the associated
mobility support signaling (e.g., maintenance of the tunnel, mobility support signaling (e.g., maintenance of the tunnel,
keep alive signaling, etc.) wastes network resources for no keep alive signaling, etc.) wastes network resources for no
application gain. In such a case, it is better to enable application gain. In such a case, it is better to enable
mobility support selectively. mobility support selectively.
PS7: (Related problem) Complicated deployment with many MIP variants PS7: (Related problem) Deployment with multiple mobility solutions
and extensions
Deployment is complicated with many variants and extensions of There are already many variants and extensions of MIP.
MIP. When introducing new functions which may add to the Deployment of new mobility management solutions can be
complexity, existing solutions are more vulnerable to break. challenging, and debugging difficult, when they must co-exist
with solutions already in the field.
PS8: Duplicate multicast traffic PS8: Duplicate multicast traffic
IP multicast distribution over architectures using IP mobility IP multicast distribution over architectures using IP mobility
solutions (e.g. RFC6224) may lead to convergence of duplicated solutions (e.g. RFC6224) may lead to convergence of duplicated
multicast subscriptions towards the downstream tunnel entity multicast subscriptions towards the downstream tunnel entity
(e.g. MAG in PMIPv6). Concretely, when multicast subscription (e.g. MAG in PMIPv6). Concretely, when multicast subscription
for individual mobile nodes is coupled with mobility tunnels for individual mobile nodes is coupled with mobility tunnels
(e.g. PMIPv6 tunnel), duplicate multicast subscription(s) is (e.g. PMIPv6 tunnel), duplicate multicast subscription(s) is
prone to be received through different upstream paths. This prone to be received through different upstream paths. This
problem may also exist or be more severe in a distributed problem may also exist or be more severe in a distributed
mobility environment. mobility environment.
5. Requirements 5. Requirements
After comparing distributed mobility management against centralized After comparing distributed mobility management against centralized
deployment in Section 3, this section identifies the following deployment in Section 3, this section identifies the following
requirements: requirements:
5.1. Distributed deployment 5.1. Distributed processing
REQ1: Distributed deployment REQ1: Distributed processing
IP mobility, network access and routing solutions provided by IP mobility, network access and routing solutions provided by
DMM MUST enable distributed deployment for mobility management DMM MUST enable distributed processing for mobility management
of some flows so that traffic does not need to traverse of some flows so that traffic does not need to traverse
centrally deployed mobility anchors and thus can be routed in centrally deployed mobility anchors and thereby avoid non-
an optimal manner. optimal routes.
Motivation: This requirement is motivated by current trends in Motivation: This requirement is motivated by current trends in
network evolution: (a) it is cost- and resource-effective to network evolution: (a) it is cost- and resource-effective to
cache and distribute content by combining distributed mobility cache and distribute content by combining distributed mobility
anchors with caching systems (e.g., CDN); (b) the anchors with caching systems (e.g., CDN); (b) the
significantly larger number of mobile nodes and flows call for significantly larger number of mobile nodes and flows call for
improved scalability; (c) single points of failure are avoided improved scalability; (c) single points of failure are avoided
in a distributed system; (d) threats against centrally in a distributed system; (d) threats against centrally
deployed anchors, e.g., home agent and local mobility anchor, deployed anchors, e.g., home agent and local mobility anchor,
are mitigated in a distributed system. are mitigated in a distributed system.
This requirement addresses problems PS1, PS2, PS3, and PS4 in Section This requirement addresses problems PS1, PS2, PS3, and PS4 in Section
4. 4. (Existing route optimization is only a host-based solution. On
the other hand, localized routing with PMIPv6 addresses only a part
of the problem where both the MN and the CN are located in the PMIP
domain and attached to a MAG, and is not applicable when the CN is
outside the PMIP domain.)
5.2. Transparency to Upper Layers when needed 5.2. Transparency to Upper Layers when needed
REQ2: Transparency to Upper Layers when needed REQ2: Transparency to Upper Layers when needed
DMM solutions MUST provide transparent mobility support above DMM solutions MUST provide transparent mobility support above
the IP layer when needed. Such transparency is needed, for the IP layer when needed. Such transparency is needed, for
example, when, upon change of point of attachment to the example, when, upon change of point of attachment to the
network, an application flow cannot cope with a change in the network, an application flow cannot cope with a change in the
IP address. However, it is not always necessary to maintain a IP address. However, it is not always necessary to maintain a
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REQ3: IPv6 deployment REQ3: IPv6 deployment
DMM solutions SHOULD target IPv6 as the primary deployment DMM solutions SHOULD target IPv6 as the primary deployment
environment and SHOULD NOT be tailored specifically to support environment and SHOULD NOT be tailored specifically to support
IPv4, in particular in situations where private IPv4 addresses IPv4, in particular in situations where private IPv4 addresses
and/or NATs are used. and/or NATs are used.
Motivation: This requirement conforms to the general Motivation: This requirement conforms to the general
orientation of IETF work. DMM deployment is foreseen in mid- orientation of IETF work. DMM deployment is foreseen in mid-
to long-term horizon, when IPv6 is expected to be far more to long-term horizon, when IPv6 is expected to be far more
common than today. It is also unnecessarily complex to solve common than today.
this problem for IPv4, as we will not be able to use some of
the IPv6-specific features/tools. This requirement avoids the unnecessarily complexity in solving the
problems in Section 4 for IPv4, which will not be able to use some of
the IPv6-specific features.
5.4. Existing mobility protocols 5.4. Existing mobility protocols
REQ4: Existing mobility protocols REQ4: Existing mobility protocols
A DMM solution SHOULD first consider reusing and extending A DMM solution SHOULD first consider reusing and extending
IETF-standardized protocols before specifying new protocols. IETF-standardized protocols before specifying new protocols.
5.5. Co-existence Motivation: Reuse of existing IETF work is more efficient and
less error-prone.
This requirement attempts to avoid the need of new protocols
development and therefore their potential problems of being time-
consuming and error-prone.
5.5. Co-existence
REQ5: Co-existence with deployed networks and hosts REQ5: Co-existence with deployed networks and hosts
The DMM solution MUST be able to co-exist with existing The DMM solution MUST be able to co-exist with existing
network deployments and end hosts. For example, depending on network deployments and end hosts. For example, depending on
the environment in which DMM is deployed, DMM solutions may the environment in which DMM is deployed, DMM solutions may
need to be compatible with other deployed mobility protocols need to be compatible with other deployed mobility protocols
or may need to co-exist with a network or mobile hosts/routers or may need to co-exist with a network or mobile hosts/routers
that do not support DMM protocols. The mobile node may also that do not support DMM protocols. The mobile node may also
move between different access networks, where some of them may move between different access networks, where some of them may
neither support DMM nor another mobility protocol. support neither DMM nor another mobility protocol.
Furthermore, a DMM solution SHOULD work across different Furthermore, a DMM solution SHOULD work across different
networks, possibly operated as separate administrative networks, possibly operated as separate administrative
domains, when allowed by the trust relationship between them. domains, when allowed by the trust relationship between them.
Motivation: (a) to preserve backwards compatibility so that Motivation: (a) to preserve backwards compatibility so that
existing networks and hosts are not affected and continue to existing networks and hosts are not affected and continue to
function as usual, and (b) enable inter-domain operation if function as usual, and (b) enable inter-domain operation if
desired. desired.
This requirement addresses the following related problem PS7 in This requirement addresses the following related problem PS7 in
Section 4. Section 4.
5.6. Security considerations 5.6. Security considerations
REQ6: Security considerations REQ6: Security considerations
DMM protocol solutions MUST consider security risks introduced DMM protocol solutions MUST consider security risks introduced
by DMM into the network. Examples of such risks to be by DMM into the network. Such considerations may include
considered are authentication and authorization mechanisms authentication and authorization mechanisms that allow a
that allow a legitimate mobile host/router to use the mobility mobile host/router to use the mobility support provided by the
support provided by the DMM solution; redirecting traffic to DMM solution; measures against redirecting traffic to the
the wrong host when providing DMM support; signaling message wrong host when providing DMM support; signaling message
protection in terms of authentication, encryption, data protection for authentication, integrity and confidentiality.
integrity and confidentiality.
Motivation: Various attacks such as impersonation, denial of Motivation: Various attacks such as impersonation, denial of
service, man-in-the-middle attacks, and so on, can be mounted service, man-in-the-middle attacks, and so on, may become
against a DMM network and need to be protected against. Proof newly possible or easier to mount due to the introduction of
of possession of past and new IP addresses may be needed. DMM. Proof of possession of past and new IP addresses may be
needed.
Signaling messages can be subject to various attacks since Signaling messages can be subject to various attacks since
they carry critical context information about a mobile node/ they carry critical context information about a mobile node/
router. For instance, a malicious node can forge a number of router. For instance, a malicious node can forge a number of
signaling messages thus redirecting traffic from its signaling messages thus redirecting traffic from its
legitimate path. Consequently, the specific node is under a legitimate path. Consequently, the specific node is under a
denial of service attack, whereas other nodes do not receive denial of service attack, whereas other nodes do not receive
their traffic. As signaling messages may travel over the their traffic. As signaling messages may travel over the
Internet, end-to-end security between communicating hosts must Internet, end-to-end security between communicating hosts must
be required. be required.
5.7. Multicast considerations This requirement addresses the problems of potentially insecure
mobility management protocols which make deployment infeasible
because platforms conforming to the protocols are at risk for data
loss and numerous other dangers, including financial harm to the
user.
REQ7: DMM should enable multicast solutions in flexible distribution 5.7. Multicast
REQ7: DMM SHOULD enable multicast solutions in flexible distribution
scenario. This flexibility pertains to the preservation of IP scenario. This flexibility pertains to the preservation of IP
multicast nature from the perspective of a mobility entiry and multicast nature from the perspective of a mobility entity and
transmission of mulitcast packets to/from varius multicast- transmission of multicast packets to/from various multicast-
enabled entities. Therefore, this flexibility enables enabled entities. Therefore, this flexibility enables
different IP multicast flows with respect to a mobile host to different IP multicast flows with respect to a mobile host to
be managed (e.g., subscribed, received and/or transmitted) be managed (e.g., subscribed, received and/or transmitted)
using multiple multicast-enabled endpoints. using multiple multicast-enabled endpoints.
Motivation: The motivation of this requirement is to consider Motivation: to consider multicast early so that solutions can
multicast early so that solutions can be developed to avoid be developed to avoid network inefficiency issues in multicast
network inefficiency issues in multicast traffic delivery. traffic delivery. The multicast solution should therefore
The multicast solution should therefore avoid restricting the avoid restricting the management of all IP multicast traffic
managment of all IP multicast traffic relative to a host relative to a host through a dedicated interface on multicast-
through a dedicated interface on multicast-capable access capable access routers.
routers.
This requirement addresses the problems PS1 and PS8 in Section 4. This requirement addresses the problems PS1 and PS8 in Section 4.
6. Security Considerations 6. Security Considerations
Distributed mobility management (DMM) requires two kinds of security Distributed mobility management (DMM) requires two kinds of security
considerations: First, access network security that only allows a considerations. The first consideration is on access network
legitimate mobile host/router to use DMM; Second, end-to-end security security required between the mobile host/router and the access
between the end hosts, which protects signaling messages for DMM. network deploying DMM. It allows only a legitimate mobile host/
Access network security is required between the mobile host/router router to use DMM. The second consideration is on end-to-end
and the access network deploying DMM. End-to-end security is security required between nodes that participate in the DMM protocol.
required between nodes that participate in the DMM protocol. It protects the DMM signaling messages.
It is necessary to provide sufficient defense against possible It is necessary to provide sufficient defense against possible
security attacks, or to adopt existing security mechanisms and security attacks, or to adopt existing security mechanisms and
protocols to provide sufficient security protections. For instance, protocols to provide sufficient security protections. For instance,
EAP-based authentication can be used for access network security, EAP-based authentication can be used for access network security,
while IPsec can be used for end-to-end security. while IPsec can be used for end-to-end security.
7. IANA Considerations 7. IANA Considerations
None None
skipping to change at page 17, line 4 skipping to change at page 17, line 23
[TS.29303] [TS.29303]
3GPP, "Domain Name System Procedures; Stage 3", 3GPP 3GPP, "Domain Name System Procedures; Stage 3", 3GPP
TR 23.303 11.2.0, September 2012. TR 23.303 11.2.0, September 2012.
Authors' Addresses Authors' Addresses
H Anthony Chan (editor) H Anthony Chan (editor)
Huawei Technologies (more co-authors on P. 17) Huawei Technologies (more co-authors on P. 17)
5340 Legacy Dr. Building 3, Plano, TX 75024, USA 5340 Legacy Dr. Building 3, Plano, TX 75024, USA
Email: h.a.chan@ieee.org Email: h.a.chan@ieee.org
Dapeng Liu Dapeng Liu
China Mobile China Mobile
Unit2, 28 Xuanwumenxi Ave, Xuanwu District, Beijing 100053, China Unit2, 28 Xuanwumenxi Ave, Xuanwu District, Beijing 100053, China
Email: liudapeng@chinamobile.com Email: liudapeng@chinamobile.com
Pierrick Seite Pierrick Seite
France Telecom - Orange Orange
4, rue du Clos Courtel, BP 91226, Cesson-Sevigne 35512, France 4, rue du Clos Courtel, BP 91226, Cesson-Sevigne 35512, France
Email: pierrick.seite@orange-ftgroup.com Email: pierrick.seite@orange.com
Hidetoshi Yokota Hidetoshi Yokota
KDDI Lab KDDI Lab
2-1-15 Ohara, Fujimino, Saitama, 356-8502 Japan 2-1-15 Ohara, Fujimino, Saitama, 356-8502 Japan
Email: yokota@kddilabs.jp Email: yokota@kddilabs.jp
Jouni Korhonen Jouni Korhonen
Nokia Siemens Networks Nokia Siemens Networks
Email: jouni.korhonen@nsn.com Email: jouni.korhonen@nsn.com
- -
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