draft-ietf-dmm-requirements-12.txt   draft-ietf-dmm-requirements-13.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: June 5, 2014 D. Liu Expires: August 4, 2014 D. Liu
China Mobile China Mobile
P. Seite P. Seite
Orange Orange
H. Yokota H. Yokota
KDDI Lab KDDI Lab
J. Korhonen J. Korhonen
Broadcom Communications Broadcom Communications
December 2, 2013 January 31, 2014
Requirements for Distributed Mobility Management Requirements for Distributed Mobility Management
draft-ietf-dmm-requirements-12 draft-ietf-dmm-requirements-13
Abstract Abstract
This document defines the requirements for Distributed Mobility This document defines the requirements for Distributed Mobility
Management (DMM). The hierarchical structure in traditional wireless Management (DMM) at the network layer. The hierarchical structure in
networks has led primarily to centralized deployment models. As some traditional wireless networks has led primarily to centralized
wireless networks are evolving away from the hierarchical structure, deployment models. As some wireless networks are evolving away from
a distributed model for mobility management can be useful to them. the hierarchical structure, a distributed model for mobility
management can be useful to them.
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 RFC 2119 document are to be interpreted as described in RFC 2119 RFC 2119
[RFC2119]. [RFC2119].
Status of this Memo Status of this Memo
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This Internet-Draft will expire on August 4, 2014.
This Internet-Draft will expire on June 5, 2014.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions used in this document . . . . . . . . . . . . . . 4 2. Conventions used in this document . . . . . . . . . . . . . . 5
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
3. Centralized versus distributed mobility management . . . . . . 5 3. Centralized versus distributed mobility management . . . . . . 6
3.1. Centralized mobility management . . . . . . . . . . . . . 6 3.1. Centralized mobility management . . . . . . . . . . . . . 7
3.2. Distributed mobility management . . . . . . . . . . . . . 7 3.2. Distributed mobility management . . . . . . . . . . . . . 8
4. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 8 4. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 9
5. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 10 5. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1. Distributed processing . . . . . . . . . . . . . . . . . . 10 6. Security Considerations . . . . . . . . . . . . . . . . . . . 14
5.2. Transparency to Upper Layers when needed . . . . . . . . . 10 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
5.3. IPv6 deployment . . . . . . . . . . . . . . . . . . . . . 11 8. Co-authors and Contributors . . . . . . . . . . . . . . . . . 14
5.4. Existing mobility protocols . . . . . . . . . . . . . . . 11 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.5. Co-existence . . . . . . . . . . . . . . . . . . . . . . . 11 9.1. Normative References . . . . . . . . . . . . . . . . . . . 14
5.6. Security considerations . . . . . . . . . . . . . . . . . 12
5.7. Multicast . . . . . . . . . . . . . . . . . . . . . . . . 12
6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8. Co-authors and Contributors . . . . . . . . . . . . . . . . . 13
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
9.1. Normative References . . . . . . . . . . . . . . . . . . . 13
9.2. Informative References . . . . . . . . . . . . . . . . . . 14 9.2. Informative References . . . . . . . . . . . . . . . . . . 14
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 network-layer mobility protocols
standardized [RFC6275] [RFC5944] [RFC5380] [RFC6301] [RFC5213]. have been standardized [RFC6275] [RFC5944] [RFC5380] [RFC6301]
Although the protocols differ in terms of functions and associated [RFC5213]. Although the protocols differ in terms of functions and
message formats, they all employ a mobility anchor to allow a mobile associated message formats, they all employ a mobility anchor to
node to remain reachable after it has moved to a different network. allow a mobile node to remain reachable after it has moved to a
The anchor point, among other tasks, ensures connectivity by different network. The anchor point, among other tasks, ensures
forwarding packets destined to, or sent from, the mobile node. It is connectivity by forwarding packets destined to, or sent from, the
a centrally deployed mobility anchor in the sense that the deployed mobile node. It is a centrally deployed mobility anchor in the sense
architectures today have a small number of these anchors and the that the deployed architectures today have a small number of these
traffic of millions of mobile nodes in an operator network are anchors and the traffic of millions of mobile nodes in an operator
typically managed by the same anchor. network are typically managed by the same anchor.
Distributed mobility management (DMM) is an alternative to the above Distributed mobility management (DMM) is an alternative to the above
centralized deployment. The background behind the interests to study centralized deployment. The background behind the interests to study
DMM are primarily in the following. DMM are primarily in the following.
(1) Mobile users are, more than ever, consuming Internet content (1) Mobile users are, more than ever, consuming Internet content
including that of local Content Delivery Networks (CDNs) which including that of local Content Delivery Networks (CDNs) which
had not taken mobility service into account before. Such had not taken mobility service into account before. Such
traffic imposes new requirements on mobile core networks for traffic imposes new requirements on mobile core networks for
data traffic delivery. To prevent exceeding the available core data traffic delivery. To prevent exceeding the available core
network capacity, service providers need to implement new network capacity, service providers need to implement new
strategies such as selective IPv4 traffic offload (e.g. strategies such as selective IPv4 traffic offload (e.g.
[RFC6909], 3GPP work items LIPA/SIPTO [TS.23.401]) through [RFC6909], 3GPP work items Local IP Access (LIPA) and Selected
alternative access networks (e.g. WLAN) [Paper- IP Traffic Offload (SIPTO) [TS.23.401]) through alternative
Mobile.Data.Offloading]. In addition, a gateway selection access networks (e.g. WLAN) [Paper-Mobile.Data.Offloading]. In
mechanism takes the user proximity into account within EPC addition, a gateway selection mechanism takes the user proximity
[TS.29303]. Yet these mechanisms were not pursued in the past into account within EPC [TS.29303]. Yet these mechanisms were
owing to charging and billing which require solutions beyond the not pursued in the past owing to charging and billing which
mobility protocol. Consequently, assigning a gateway anchor require solutions beyond the mobility protocol. Consequently,
node from a visited network in roaming scenario has until assigning a gateway anchor node from a visited network in
recently been done and are limited to voice services only. roaming scenario has until recently been done and are limited to
voice services only.
Both traffic offloading and CDN mechanisms could benefit from Both traffic offloading and CDN mechanisms could benefit from
the development of mobile architectures with fewer levels of the development of mobile architectures with fewer levels of
routing hierarchy introduced into the data path by the mobility routing hierarchy introduced into the data path by the mobility
management system. This trend towards so-called "flat networks" management system. This trend towards so-called "flat networks"
works best for direct communications among peers in the same works best for direct communications among peers in the same
geographical area. Distributed mobility management in a truly geographical area. Distributed mobility management in a truly
flat mobile architecture would anchor the traffic closer to the flat mobile architecture would anchor the traffic closer to the
point of attachment of the user. point of attachment of the user.
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mobility support is designed for always-on operation, mobility support is designed for always-on operation,
maintaining all parameters of the context for each mobile maintaining all parameters of the context for each mobile
subscriber for as long as they are connected to the network. subscriber for as long as they are connected to the network.
This can result in a waste of resources and unnecessary costs This can result in a waste of resources and unnecessary costs
for the service provider. Infrequent node mobility coupled with for the service provider. Infrequent node mobility coupled with
application intelligence suggest that mobility support could be application intelligence suggest that mobility support could be
provided selectively such as in [I-D.bhandari-dhc-class-based- provided selectively such as in [I-D.bhandari-dhc-class-based-
prefix] and [I-D.korhonen-6man-prefix-properties], thus reducing prefix] and [I-D.korhonen-6man-prefix-properties], thus reducing
the amount of context maintained in the network. the amount of context maintained in the network.
The distributed mobility management (DMM) charter addresses two DMM may distribute the mobility anchors in the data-plane towards a
complementary aspects of mobility management procedures: the more flat network such that the mobility anchors are positioned
distribution of mobility anchors in the data-plane towards a more
flat network and the selective activation/deactivation of mobility
protocol support as an enabler to distributed mobility management.
The former aims at positioning mobility anchors (e.g., HA, LMA)
closer to the user; ideally, mobility agents could be collocated with closer to the user; ideally, mobility agents could be collocated with
the first-hop router. The latter, facilitated by the distribution of the first-hop router. Facilitated by the distribution of mobility
mobility anchors, identifies when mobility support must be activated anchors, DMM may also selectively activate/deactivate mobility
and when sessions do not require mobility management support -- thus protocol support. There is need to identify when mobility support
reducing the amount of state information that must be maintained in must be activated and when sessions do not require mobility
various mobility agents of the mobile network. It can then avoid the management support. It can thus reduce the amount of state
unnecessary establishment of mechanisms to forward traffic from an information that must be maintained in various mobility agents of the
old to a new mobility anchor. mobile network. It can then avoid the unnecessary establishment of
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 mandatory be addressed with DMM are summarized in Section 4. The mandatory
requirements as well as the optional requirements are given in requirements as well as the optional requirements for network-layer
Section 5. Finally, security considerations are discussed in Section distributed mobility management are given in Section 5. Finally,
6. 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
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
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has few levels of routing hierarchy introduced into the data path has few levels of routing hierarchy introduced into the data path
by the mobility management system. by the mobility management system.
Mobility context Mobility context
is the collection of information required to provide mobility is the collection of information required to provide mobility
management support for a given mobile node. management support for a given mobile node.
3. Centralized versus distributed mobility management 3. Centralized versus distributed mobility management
Mobility management functions may be implemented at different layers Mobility management is needed because the IP address of a mobile node
of the protocol stack. At the IP (network) layer, mobility may change as the node moves. Mobility management functions may be
management can be client-based or network-based. implemented at different layers of the protocol stack. At the IP
(network) layer, mobility management can be client-based or network-
based.
An IP-layer mobility management protocol is typically based on the An IP-layer mobility management protocol is typically based on the
principle of distinguishing between session identifier and routing principle of distinguishing between a session identifier and a
address and maintaining a mapping between the two. In Mobile IP, the routing address and maintaining a mapping between the two. In Mobile
home address serves as the session identifier whereas the care-of- IP, the new IP address of the mobile node after the node has moved is
address (CoA) takes the role of the routing address. The binding the routing address, whereas the original IP address before the
between these two is maintained at the home agent (mobility anchor). mobile node moves serves as the session identifier. The location
If packets addressed to the home address of a mobile node can be management (LM) information is kept by associating the routing
continuously delivered to the node, then all sessions using that home address with the session identifier. Packets addressed to the
address are unaffected even though the routing address (CoA) changes. session identifier will first route to the original network which re-
directs them using the routing address to deliver to the session.
Re-directing packets this way can result in long routes. An existing
optimization routes directly using the routing address of the host,
and such is a host-based solution.
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 location information in terms
the session identifier and the locator IP address of a mobile node of a mapping between the session identifier and the routing address
(MN) is kept at a single mobility anchor. At the same time, packets is kept at a single mobility anchor, and packets destined to the
destined to the MN are routed via this anchor. In other words, such session identifier are routed via this anchor. In other words, such
mobility management systems are centralized in both the control plane mobility management systems are centralized in both the control plane
and the data plane (mobile node IP traffic). 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 are the home agent (HA) and local mobility
home agent (HA) and local mobility anchor (LMA) in Mobile IPv6 anchor (LMA) serving as the anchors for the mobile node (MN) and
[RFC6275] and Proxy Mobile IPv6 [RFC5213], respectively. Current Mobile Access Gateway (MAG) in Mobile IPv6 [RFC6275] and in Proxy
cellular networks such as the Third Generation Partnership Project Mobile IPv6 [RFC5213] respectively. Cellular networks such as the
(3GPP) GPRS networks, CDMA networks, and 3GPP Evolved Packet System Third Generation Partnership Project (3GPP) General Packet Radio
(EPS) networks employ centralized mobility management too. In System (GPRS) networks and 3GPP Evolved Packet System (EPS) networks
particular, the Gateway GPRS Support Node (GGSN), Serving GPRS employ centralized mobility management too. In the 3GPP GPRS
Support Node (SGSN) and Radio Network Controller (RNC) in the 3GPP network, the Gateway GPRS Support Node (GGSN), Serving GPRS Support
GPRS hierarchical network, and the Packet Data Network Gateway (P-GW) Node (SGSN) and Radio Network Controller (RNC) constitute a hierarchy
and Serving Gateway (S-GW) in the 3GPP EPS network all act as anchors of anchors. In the 3GPP EPS network, the Packet Data Network Gateway
in a hierarchy. (P-GW) and Serving Gateway (S-GW) constitute another hierarchy of
anchors.
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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+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
|RNC| |RNC| |RNC| |RNC| |RNC| |RNC| |RNC| |RNC|
+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
Figure 1. Centralized mobility management. Figure 1. Centralized mobility management.
3.2. Distributed mobility management 3.2. Distributed mobility management
Mobility management functions may also be distributed to multiple Mobility management functions may also be distributed to multiple
networks as shown in Figure 2, so that a mobile node in any of these networks as shown in Figure 2, so that a mobile node in any of these
networks may be served by a nearby function with appropriate routing/ networks may be served by a nearby function with appropriate
mobility management (RM) capability. mobility/routing management (RM) capability.
+------+ +------+ +------+ +------+ +------+ +------+ +------+ +------+
| RM | | RM | | RM | | RM | | RM | | RM | | RM | | RM |
+------+ +------+ +------+ +------+ +------+ +------+ +------+ +------+
| |
+----+ +----+
| MN | | MN |
+----+ +----+
Figure 2. Distributed mobility management. Figure 2. Distributed mobility management.
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PS1: Non-optimal routes PS1: Non-optimal routes
Routing via a centralized anchor often results in non-optimal Routing via a centralized anchor often results in non-optimal
routes, thereby increasing the end-to-end delay. The problem routes, thereby increasing the end-to-end delay. The problem
is manifested, for example, when accessing a nearby server or is manifested, for example, when accessing a nearby server or
servers of a Content Delivery Network (CDN), or when receiving servers of a Content Delivery Network (CDN), or when receiving
locally available IP multicast or sending IP multicast packets. locally available IP multicast or sending IP multicast packets.
(Existing route optimization is only a host-based solution. On (Existing route optimization is only a host-based solution. On
the other hand, localized routing with PMIPv6 [RFC6705] the other hand, localized routing with PMIPv6 [RFC6705]
addresses only a part of the problem where both the MN and the addresses only a part of the problem where both the MN and the
CN are attached to the same MAG, and it is not applicable when correspondent node (CN) are attached to the same MAG, and it is
the CN does not behave like an MN.) not applicable when the CN does not behave like an MN.)
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.
Mobile networks have generally been evolving towards a flat Mobile networks have generally been evolving towards a flat
network. Centralized mobility management, which is non-optimal network. Centralized mobility management, which is non-optimal
with a flat network architecture, does not support this with a flat network architecture, does not support this
evolution. evolution.
PS3: Scalability of centralized tunnel management and mobility PS3: Lack of scalability of centralized tunnel management and
context maintenance mobility 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 usually requires more concentrated mobility context for each MN usually requires more concentrated
resources in a centralized design, thus reducing scalability. resources in a centralized design, thus reducing scalability.
Distributing the tunnel maintenance function and the mobility Distributing the tunnel maintenance function and the mobility
context maintenance function among different network entities context maintenance function among different network entities
with proper signaling protocol design can avoid increasing the with proper signaling protocol design can avoid increasing the
concentrated resources with an increasing number of MNs. concentrated resources with an increasing number of MNs.
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: Unnecessary mobility support to clients that do not need it PS5: Unnecessary mobility support to clients that do not need it
IP mobility support is usually provided to all MNs. Yet it is IP mobility support is usually provided to all MNs. Yet it is
not always required, and not every parameter of mobility not always required, and not every parameter of mobility
context is always used. For example, some applications do not context is always used. For example, some applications or
need a stable IP address during a handover to maintain session nodes do not need a stable IP address during a handover to
continuity. Sometimes, the entire application session runs maintain session continuity. Sometimes, the entire application
while the terminal does not change the point of attachment. session runs while the MN does not change the point of
Besides, some sessions, e.g. SIP-based sessions, can handle attachment. Besides, some sessions, e.g. SIP-based sessions,
mobility at the application layer and hence do not need IP can handle mobility at the application layer and hence do not
mobility support; it is then unnecessary to provide IP mobility need IP mobility support; it is then unnecessary to provide IP
support for such sessions. mobility support for such sessions.
PS6: (Related problem) Mobility signaling overhead with peer-to-peer PS6: 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 communication.
PS7: (Related problem) Deployment with multiple mobility solutions PS7: Deployment with multiple mobility solutions
There are already many variants and extensions of MIP. There are already many variants and extensions of MIP as well
Deployment of new mobility management solutions can be mobility solutions at other layers. Deployment of new mobility
challenging, and debugging difficult, when they co-exist with management solutions can be challenging, and debugging
solutions already deployed in the field. difficult, when they co-exist with solutions already deployed
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 solutions (e.g., [RFC6224]) may lead to convergence of
duplicated multicast subscriptions towards the downstream duplicated multicast subscriptions towards the downstream
tunnel entity (e.g. MAG in PMIPv6). Concretely, when tunnel entity (e.g. MAG in PMIPv6). Concretely, when
multicast subscription for individual mobile nodes is coupled multicast subscription for individual mobile nodes is coupled
with mobility tunnels (e.g. PMIPv6 tunnel), duplicate with mobility tunnels (e.g. PMIPv6 tunnel), duplicate
multicast subscription(s) is prone to be received through multicast subscription(s) is prone to be received through
different upstream paths. This problem may also exist or be different upstream paths. This problem may also exist or be
more severe in a distributed mobility environment. more severe in a distributed 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 and describing the problems in Section 4,
requirements: this section identifies the following requirements:
5.1. Distributed processing
REQ1: Distributed processing 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 processing for mobility management DMM MUST enable distributed processing for mobility management
so that traffic can avoid traversing single mobility anchor so that traffic can avoid traversing single mobility anchor
far from the optimal route. far from the optimal route.
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 contents, and the caching (e.g., CDN) servers are
anchors with caching systems (e.g., CDN); (b) the distributed so that each user in any location can be close to
significantly larger number of mobile nodes and flows call for one of the servers; (b) the significantly larger number of
improved scalability; (c) single points of failure are avoided mobile nodes and flows call for improved scalability; (c)
in a distributed system; (d) threats against centrally single points of failure are avoided in a distributed system;
deployed anchors, e.g., home agent and local mobility anchor, (d) threats against centrally deployed anchors, e.g., home
are mitigated in a distributed system. agent and local mobility anchor, are mitigated in a
distributed system.
This requirement addresses the problems PS1, PS2, PS3, and PS4 This requirement addresses the problems PS1, PS2, PS3, and PS4
described in Section 4. described in Section 4.
5.2. Transparency to Upper Layers when needed REQ2: Bypassable network-layer mobility support
REQ2: Transparency to Upper Layers when needed
DMM solutions MUST provide transparent mobility support above DMM solutions MUST enable network-layer mobility but it MUST
the IP layer when needed. Such transparency is needed, for be possible to not use it. Mobility support is needed, for
example, when, upon change of point of attachment to the example, when a mobile host moves and an application cannot
network, an application flow cannot cope with a change in the cope with a change in the IP address. Mobility support is
IP address. However, it is not always necessary to maintain a also needed, for example, when a mobile router moves together
stable home IP address or prefix for every application or at with a host and an application in the host is interrupted by a
all times for a mobile node. change of IP address of the mobile router. However mobility
support at the network-layer is not always needed; a mobile
node can often be stationary, and mobility support can also be
provided at other layers. It is then not always necessary to
maintain a stable IP address or prefix.
Motivation: The motivation of this requirement is to enable Motivation: The motivation of this requirement is to enable
more efficient routing and more efficient use of network more efficient routing and more efficient use of network
resources by selecting an IP address or prefix according to resources by selecting an IP address or prefix according to
whether mobility support is needed and by not maintaining whether mobility support is needed and by not maintaining
context at the mobility anchor when there is no such need. context at the mobility anchor when there is no such need.
This requirement addresses the problem PS5 as well as the related This requirement addresses the problems PS5 and PS6 described in
problem PS6 stated in Section 4. Section 4.
5.3. IPv6 deployment
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. common than today.
This requirement avoids the unnecessarily complexity in solving the This requirement avoids the unnecessarily complexity in solving the
problems in Section 4 for IPv4, which will not be able to use some of problems in Section 4 for IPv4, which will not be able to use some of
the IPv6-specific features. the IPv6-specific features.
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 MUST first consider reusing and extending IETF-
IETF-standardized protocols before specifying new protocols. standardized protocols before specifying new protocols.
Motivation: Reuse of existing IETF work is more efficient and Motivation: Reuse of existing IETF work is more efficient and
less error-prone. less error-prone.
This requirement attempts to avoid the need of new protocols This requirement attempts to avoid the need of new protocols
development and therefore their potential problems of being time- development and therefore their potential problems of being time-
consuming and error-prone. consuming and error-prone.
5.5. Co-existence REQ5: Coexistence 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 may require loose, tight or no integration
network deployments and end hosts. For example, depending on into existing mobility protocols and host IP stack.
the environment in which DMM is deployed, DMM solutions may Regardless of the integration level, the DMM solution MUST be
need to be compatible with other deployed mobility protocols able to coexist with existing network deployments, end hosts
or may need to co-exist with a network or mobile hosts/routers and routers that may or may not implement existing mobility
that do not support DMM protocols. The mobile node may also protocols. Furthermore, a DMM solution SHOULD work across
move between different access networks, where some of them may different networks, possibly operated as separate
support neither DMM nor another mobility protocol. administrative domains, when allowed by the trust relationship
Furthermore, a DMM solution SHOULD work across different between them.
networks, possibly operated as separate administrative
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 related problem PS7 described in This requirement addresses the problem PS7 described in Section 4.
Section 4.
5.6. Security considerations
REQ6: Security considerations REQ6: Security considerations
A DMM solution MUST NOT introduce new security risks or A DMM solution MUST NOT introduce new security risks, or
amplify existing security risks against which the existing amplify existing security risks, that cannot be mitigated by
security mechanisms/protocols cannot offer sufficient existing security mechanisms or protocols.
protection.
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, may be launched service, man-in-the-middle attacks, and so on, may be launched
in a DMM deployment. For instance, an illegitimate node may in a DMM deployment. For instance, an illegitimate node may
attempt to access a network providing DMM. Another example is attempt to access a network providing DMM. Another example is
that a malicious node can forge a number of signaling messages that a malicious node can forge a number of signaling messages
thus redirecting traffic from its legitimate path. thus redirecting traffic from its legitimate path.
Consequently, the specific node is under a denial of service Consequently, the specific node is under a denial of service
attack, whereas other nodes do not receive their traffic. attack, whereas other nodes do not receive their traffic.
Accordingly, security mechanisms/protocols providing access Accordingly, security mechanisms/protocols providing access
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confidentiality, etc. can be used to protect the DMM entities confidentiality, etc. can be used to protect the DMM entities
as they are already used to protect against existing networks as they are already used to protect against existing networks
and existing mobility protocols defined in IETF. and existing mobility protocols defined in IETF.
This requirement prevents a DMM solution from introducing This requirement prevents a DMM solution from introducing
uncontrollable problems of potentially insecure mobility management uncontrollable problems of potentially insecure mobility management
protocols which make deployment infeasible because platforms protocols which make deployment infeasible because platforms
conforming to the protocols are at risk for data loss and numerous conforming to the protocols are at risk for data loss and numerous
other dangers, including financial harm to the users. other dangers, including financial harm to the users.
5.7. Multicast
REQ7: Multicast considerations REQ7: Multicast considerations
DMM SHOULD enable multicast solutions to be developed to avoid DMM SHOULD enable multicast solutions to be developed to avoid
network inefficiency in multicast traffic delivery. network inefficiency in multicast traffic delivery.
Motivation: Existing multicast deployment have been introduced Motivation: Existing multicast deployment have been introduced
after completing the design of the reference mobility after completing the design of the reference mobility
protocol, often leading to network inefficiency and non- protocol, often leading to network inefficiency and non-
optimal routing for the multicast traffic. Instead DMM should optimal routing for the multicast traffic. Instead DMM should
consider multicast early so that the multicast solutions can consider multicast early so that the multicast solutions can
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Broadcom Communications Broadcom Communications
Porkkalankatu 24, FIN-00180 Helsinki, Finland Porkkalankatu 24, FIN-00180 Helsinki, Finland
Email: jouni.nospam@gmail.com Email: jouni.nospam@gmail.com
- -
Charles E. Perkins Charles E. Perkins
Huawei Technologies Huawei Technologies
Email: charliep@computer.org Email: charliep@computer.org
- -
Melia Telemaco Melia Telemaco
Alcatel-Lucent Bell Labs Alcatel-Lucent Bell Labs
Email: telemaco.melia@alcatel-lucent.com Email: telemaco.melia@googlemail.com
- -
Elena Demaria Elena Demaria
Telecom Italia Telecom Italia
via G. Reiss Romoli, 274, TORINO, 10148, Italy via G. Reiss Romoli, 274, TORINO, 10148, Italy
Email: elena.demaria@telecomitalia.it Email: elena.demaria@telecomitalia.it
- -
Jong-Hyouk Lee Jong-Hyouk Lee
Sangmyung University Sangmyung University, Korea
Email: hurryon@gmail.com Email: jonghyouk@smu.ac.kr
- -
Kostas Pentikousis Kostas Pentikousis
EICT GmbH EICT GmbH
Email: k.pentikousis@eict.de Email: k.pentikousis@eict.de
- -
Tricci So Tricci So
ZTE ZTE
Email: tso@zteusa.com Email: tso@zteusa.com
- -
Carlos J. Bernardos Carlos J. Bernardos
skipping to change at page 18, line 43 skipping to change at page 19, line 26
- -
Alexandru Petrescu Alexandru Petrescu
Email: alexandru.petrescu@gmail.com Email: alexandru.petrescu@gmail.com
- -
Georgios Karagiannis Georgios Karagiannis
University of Twente University of Twente
Email: g.karagiannis@utwente.nl Email: g.karagiannis@utwente.nl
- -
Julien Laganier Julien Laganier
Juniper Juniper
jlaganier@juniper.net julien.ietf@gmail.com
- -
Wassim Michel Haddad Wassim Michel Haddad
Ericsson Ericsson
Wassam.Haddad@ericsson.com Wassim.Haddad@ericsson.com
- -
Dirk von Hugo Dirk von Hugo
Deutsche Telekom Laboratories Deutsche Telekom Laboratories
Dirk.von-Hugo@telekom.de Dirk.von-Hugo@telekom.de
- -
Ahmad Muhanna Ahmad Muhanna
Award Solutions Award Solutions
amuhanna@awardsolutions.com asmuhanna@yahoo.com
- -
Byoung-Jo Kim Byoung-Jo Kim
ATT Labs ATT Labs
macsbug@research.att.com macsbug@research.att.com
- -
Hassan Ali-Ahmad Hassan Ali-Ahmad
Orange Orange
hassan.aliahmad@orange.com hassan.aliahmad@orange.com
- -
Alper Yegin Alper Yegin
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