Re: I-D Action: draft-ietf-dmm-requirements-07.txt
h chan <[email protected]>
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After checking the definitions section, the following definition is changed as follows:
Distributed mobility management
is not centralized so that traffic does not need to traverse
centrally deployed mobility anchors.
Change to:
Distributed mobility management
is not centralized so that traffic does not need to traverse
centrally deployed mobility anchors far from the optimal route.
H Anthony Chan
From: h chan
Sent: Tuesday, November 19, 2013 8:12 PM
To: 'Sri Gundavelli (sgundave)'; [email protected]
Subject: RE: [DMM] I-D Action: draft-ietf-dmm-requirements-07.txt
Sri,
Suggested revisions are shown in blue below.
Not sure about what improvements are desired for the definitions though.
H Anthony Chan
From: Sri Gundavelli (sgundave) [mailto:[email protected]]
Sent: Sunday, November 17, 2013 4:27 PM
To: h chan; [email protected]<mailto:[email protected]>
Subject: Re: [DMM] I-D Action: draft-ietf-dmm-requirements-07.txt
Hi Anthony,
Thanks for revising the draft. Following are some more comments on the document. I'm not holding this document any more. What ever comments you can address ... or you can choose not to revise ...
Please see inline.
Regards
Sri
From: h chan <[email protected]<mailto:[email protected]>>
Date: Wednesday, September 25, 2013 9:49 PM
To: Sri Gundavelli <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Subject: RE: [DMM] I-D Action: draft-ietf-dmm-requirements-07.txt
Sri,
Thanks for the comments. We are replying under different sections in separate emails.
Network Working Group H. Chan (Ed.)
Internet-Draft Huawei Technologies (more
Intended status: Informational co-authors on P. 17)
Expires: May 11, 2014 D. Liu
China Mobile
P. Seite
Orange
H. Yokota
KDDI Lab
J. Korhonen
Renesas Mobile
November 7, 2013
Requirements for Distributed Mobility Management
draft-ietf-dmm-requirements-10
Abstract
This document defines the requirements for Distributed Mobility
Management (DMM). The hierarchical structure in traditional wireless
networks has led primarily to centralized deployment models. As some
wireless networks are evolving away from the hierarchical structure,
such as in moving the content delivery servers closer to the users, a
distributed model for mobility management can be useful to them.
[Sri] Not sure, what the "hierarchical structure in traditional wireless" means.
There are two aspects here:
1.) There is the aspect of distributed mobility deployment model for all the reasons that the document talks about
2.) There is the other aspect of hosting content servers closer to the subscriber
I'm not able to draw the relation between "moving content to the access" and the shift from centralized to distributed model. I understand you want to say today there are central anchors where subscriber sessions are hosted. All the traffic from the mobile node's is brought to the central location/anchor for service enablement and including content access. An alternative model is to distribute the anchors, localize the traffic and enable the associated services to local anchors. You may want to re-write the text if you want to get that right.
Let us delete "such as in moving the content delivery servers closer to the users,"
Then the abstract becomes:
Abstract
This document defines the requirements for Distributed Mobility
Management (DMM). The hierarchical structure in traditional wireless
networks has led primarily to centralized deployment models. As some
wireless networks are evolving away from the hierarchical structure,
a
distributed model for mobility management can be useful to them.
Requirements Language
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 RFC 2119 RFC 2119
[RFC2119].
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
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This Internet-Draft will expire on May 11, 2014.
Copyright Notice
Copyright (c) 2013 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
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions used in this document . . . . . . . . . . . . . . 6
2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 6
3. Centralized versus distributed mobility management . . . . . . 7
3.1. Centralized mobility management . . . . . . . . . . . . . 7
3.2. Distributed mobility management . . . . . . . . . . . . . 8
4. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 9
5. Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1. Distributed processing . . . . . . . . . . . . . . . . . . 11
5.2. Transparency to Upper Layers when needed . . . . . . . . . 11
5.3. IPv6 deployment . . . . . . . . . . . . . . . . . . . . . 12
5.4. Existing mobility protocols . . . . . . . . . . . . . . . 12
5.5. Co-existence . . . . . . . . . . . . . . . . . . . . . . . 13
5.6. Security considerations . . . . . . . . . . . . . . . . . 13
5.7. Multicast . . . . . . . . . . . . . . . . . . . . . . . . 14
6. Security Considerations . . . . . . . . . . . . . . . . . . . 14
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
8. Co-authors and Contributors . . . . . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
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1. Introduction
In the past decade a fair number of mobility protocols have been
standardized [RFC6275] [RFC5944] [RFC5380] [RFC6301] [RFC5213].
Although the protocols differ in terms of functions and associated
message formats, they all employ a mobility anchor to allow a mobile
node to remain reachable after it has moved to a different network.
The anchor point, among other tasks, ensures connectivity by
forwarding packets destined to, or sent from, the mobile node. It is
a centrally deployed mobility anchor in the sense that the deployed
architectures today have a small number of these anchors and the
traffic of millions of mobile nodes in an operator network are
typically managed by the same anchor.
Distributed mobility management (DMM) is an alternative to the above
centralized deployment. The background behind the interests to study
DMM are primarily in the following.
(1) Mobile users are, more than ever, consuming Internet content;
such traffic imposes new requirements on mobile core networks
for data traffic delivery. The presence of content providers
closer to Internet Service Providers (ISP) network requires
taking into account local Content Delivery Networks (CDNs) while
providing mobility services. Moreover, when the traffic demand
exceeds available capacity, service providers need to implement
new strategies such as selective IPv4 traffic offload (e.g.
[RFC6909], 3GPP work items LIPA/SIPTO [TS.23.401]) through
alternative access networks (e.g. WLAN) [Paper-
Mobile.Data.Offloading]. A gateway selection mechanism also
takes the user proximity into account within EPC [TS.29303].
These mechanisms were not pursued in the past owing to charging
and billing reasons. Assigning a gateway anchor node from a
visited network in roaming scenario has until recently been done
and are limited to voice services only. Charging and billing
require solutions beyond the mobility protocol.
[Sri] Some valid points above. But, IMHO, its not organized correctly.
My only comment with this document is that this has text from multiple people with different goals, but is not organized poorly.
Reminds me of some SDO documents. There the document starts with a blank template, every company spits a line or two and in no time, the document grows like a monster, but there is no relation between two lines of text in the same paragraph. No offense.
Rearrange as follows:
(1) Mobile users are, more than ever, consuming Internet content
including that of local Content Delivery Networks (CDNs) which
had not taken mobility service into account before. Such
traffic imposes new requirements on mobile core networks for
data traffic delivery. To prevent exceeding the available core
network capacity, service providers need to implement new
strategies such as selective IPv4 traffic offload (e.g.
[RFC6909], 3GPP work items LIPA/SIPTO [TS.23.401]) through
alternative access networks (e.g. WLAN) [Paper-
Mobile.Data.Offloading]. In addition, a gateway selection
mechanism takes the user proximity into account within EPC
[TS.29303]. Yet these mechanisms were not pursued in the past
owing to charging and billing which require solutions beyond the
mobility protocol. Consequently, assigning a gateway anchor
node from a visited network in roaming scenario has until
recently been done and are limited to voice services only.
Both traffic offloading and CDN mechanisms could benefit from
the development of mobile architectures with fewer levels of
routing hierarchy introduced into the data path by the mobility
management system. This trend towards so-called "flat networks"
works best for direct communications among peers in the same
geographical area. Distributed mobility management in a truly
flat mobile architecture would anchor the traffic closer to the
point of attachment of the user.
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(2) Today's mobile networks present service providers with new
challenges. Mobility patterns indicate that mobile nodes often
remain attached to the same point of attachment for considerable
periods of time [Paper-Locating.User]. Specific IP mobility
management support is not required for applications that launch
and complete their sessions while the mobile node is connected
to the same point of attachment. However, currently, IP
mobility support is designed for always-on operation,
maintaining all parameters of the context for each mobile
subscriber for as long as they are connected to the network.
This can result in a waste of resources and unnecessary costs
for the service provider. Infrequent node mobility coupled with
application intelligence suggest that mobility support could be
provided selectively such as in [I-D.bhandari-dhc-class-based-
prefix] and [I-D.korhonen-6man-prefix-properties], thus reducing
the amount of context maintained in the network.
Let us delete the following, which don't seem necessary. The requirements already have the problem statements to support them.
In addition, considerations in the study of DMM are in the following.
(1) To optimize handovers from the perspective of mobile nodes, the
base protocols have been extended to efficiently handle packet
forwarding between the previous and new points of attachment.
These extensions are necessary when applications have stringent
requirements in terms of delay. Notions of localization and
distribution of local agents have been introduced to reduce
signaling overhead at the centralized routing anchor point
[Paper-Distributed.Centralized.Mobility]. Unfortunately, such
protocols have not been deployed today.
(2) Most existing mobility protocols have not been designed for
multiple-interface hosts which are capable to use multiple
interfaces simultaneously. Retrofitting the required
functionality can result in an unnecessary increase in the
protocol complexity.
RFC5648.
Not sure. I agree about the complexity. Any case, this is not a DMM requirement
(3) IP multicast support, including optimizations, have been
introduced as an effective transport method for multimedia data
delivery, but by "patching-up" procedure after completing the
design of reference mobility protocol, leading to network
inefficiency and non-optimal routing.
I dont understand this.
The distributed mobility management (DMM) charter addresses two
complementary aspects of mobility management procedures: the
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
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the first-hop router. The latter, facilitated by the distribution of
mobility anchors, identifies when mobility support must be activated
and when sessions do not require mobility management support -- thus
reducing the amount of state information that must be maintained in
various mobility agents of the 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
centralized mobility management in Section 3. The problems that can
be addressed with DMM are summarized in Section 4. The mandatory
requirements as well as the optional requirements are given in
Section 5. Finally, security considerations are discussed in Section
6.
The problem statement and the use cases [I-D.yokota-dmm-scenario] can
be found in [Paper-Distributed.Mobility.Review].
2. Conventions used in this document
2.1. Terminology
All the general mobility-related terms and their acronyms used in
this document are to be interpreted as defined in the Mobile IPv6
base specification [RFC6275], in the Proxy mobile IPv6 specification
[RFC5213], and in Mobility Related Terminology [RFC3753]. These
terms include the following: mobile node (MN), correspondent node
(CN), and home agent (HA) as per [RFC6275]; local mobility anchor
(LMA) and mobile access gateway (MAG) as per [RFC5213], and context
as per [RFC3753].
In addition, this draft introduces the following terms.
Centrally deployed mobility anchors
refer to the mobility management deployments in which there are
very few mobility anchors and the traffic of millions of mobile
nodes in an operator network are managed by the same anchor.
Centralized mobility management
makes use of centrally deployed mobility anchors.
Distributed mobility management
is not centralized so that traffic does not need to traverse
centrally deployed mobility anchors.
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Flat mobile network
has few levels of routing hierarchy introduced into the data path
by the mobility management system.
Mobility context
is the collection of information required to provide mobility
management support for a given mobile node.
You can improve the terminology section
Not sure whether you want to better define these terms or whether some definitions are missing?
3. Centralized versus distributed mobility management
Mobility management functions may be 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
principle of distinguishing between session identifier and routing
address and maintaining a mapping between the two. In Mobile IP, the
home address serves as the session identifier whereas the care-of-
address (CoA) takes the role of the routing address. The binding
between these two is maintained at the home agent (mobility anchor).
If packets addressed to the home address of a mobile node can be
continuously delivered to the node, then all sessions using that home
address are unaffected even though the routing address (CoA) changes.
The next two subsections explain centralized and distributed mobility
management functions in the network.
3.1. Centralized mobility management
In centralized mobility management, the mapping information between
the session identifier and the locator IP address of a mobile 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 words, such
mobility management systems are centralized in both the control plane
and the data plane (mobile node IP traffic).
Many existing mobility management deployments make use of centralized
mobility anchoring in a hierarchical network architecture, as shown
in Figure 1. Examples of such centralized mobility anchors are the
home agent (HA) and local mobility anchor (LMA) in Mobile IPv6
[RFC6275] and Proxy Mobile IPv6 [RFC5213], respectively. Current
cellular networks such as the Third Generation Partnership Project
(3GPP) GPRS networks, CDMA networks, and 3GPP Evolved Packet System
(EPS) networks employ centralized mobility management too. In
particular, the Gateway GPRS Support Node (GGSN), Serving GPRS
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Support Node (SGSN) and Radio Network Controller (RNC) in the 3GPP
GPRS hierarchical network, and the Packet Data Network Gateway (P-GW)
and Serving Gateway (S-GW) in the 3GPP EPS network all act as anchors
in a hierarchy.
3G GPRS 3GPP EPS MIP/PMIP
+------+ +------+ +------+
| GGSN | | P-GW | |HA/LMA|
+------+ +------+ +------+
/\ /\ /\
/ \ / \ / \
/ \ / \ / \
/ \ / \ / \
/ \ / \ / \
/ \ / \ / \
/ \ / \ / \
+------+ +------+ +------+ +------+ +------+ +------+
| SGSN | | SGSN | | S-GW | | S-GW | |MN/MAG| |MN/MAG|
+------+ +------+ +------+ +------+ +------+ +------+
/\ /\
/ \ / \
/ \ / \
+---+ +---+ +---+ +---+
|RNC| |RNC| |RNC| |RNC|
+---+ +---+ +---+ +---+
Figure 1. Centralized mobility management.
3.2. Distributed mobility management
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 may be served by a nearby mobility function (MF).
+------+ +------+ +------+ +------+
| MF | | MF | | MF | | MF |
+------+ +------+ +------+ +------+
|
+----+
| MN |
+----+
Figure 2. Distributed mobility management.
Mobility management may be partially or fully distributed
[I-D.yokota-dmm-scenario]. In the former case only the data plane is
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distributed, implicitly assuming separation of data and control
planes as described in [I-D.wakikawa-netext-pmip-cp-up-separtion].
Fully distributed mobility management implies that both the data
plane and the control plane are distributed. While mobility
management can be distributed, it is not necessary for other
functions such as subscription management, subscription database, and
network access authentication to be similarly distributed.
A distributed mobility management scheme for a flat mobile network of
access nodes is proposed in [Paper-Distributed.Dynamic.Mobility].
Its benefits over centralized mobility management are shown through
simulations in [Paper-Distributed.Centralized.Mobility]. Moreover,
the (re)use and extension of existing protocols in the design of both
fully distributed mobility management [Paper-Migrating.Home.Agents]
[Paper-Distributed.Mobility.SAE] and partially distributed mobility
management [Paper-Distributed.Mobility.PMIP] [Paper-
Distributed.Mobility.MIP] have been reported in the literature.
Therefore, before designing new mobility management protocols for a
future distributed architecture, it is recommended to first consider
whether existing mobility management protocols can be extended.
4. Problem Statement
The problems that can be addressed with DMM are summarized in the
following:
PS1: Non-optimal routes
Routing via a centralized anchor often results in non-optimal
routes, thereby increasing the end-to-end delay. The problem
is manifested, for example, when accessing a nearby server or
servers of a Content Delivery Network (CDN), or when receiving
locally available IP multicast or sending IP multicast packets.
(Existing route optimization is only a host-based solution. On
the other hand, localized routing with PMIPv6 [RFC6705]
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 or does
not behave like an MN.)
You argue for optimized route when accessing a CDN server in the local network. But you say that the localized routing schemes don't work when the CN is outside the PMIP domain. What is the point ? When the CN is outside the PMIP domain, where is optimized route possibility ?
So, PS1 is about optimized routing requirement in DMM. Even though the document fails to make the case that the current models have an issue, I'm OK with optimized routing goal for DMM in general terms.
Revise as follows:
Routing via a centralized anchor often results in non-optimal
routes, thereby increasing the end-to-end delay. The problem
is manifested, for example, when accessing a nearby server or
servers of a Content Delivery Network (CDN), or when receiving
locally available IP multicast or sending IP multicast packets.
(Existing route optimization is only a host-based solution. On
the other hand, localized routing with PMIPv6 [RFC6705]
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
the CN does not behave like an MN.)
PS2: Divergence from other evolutionary trends in network
architectures such as distribution of content delivery.
Centralized mobility management can become non-optimal with a
flat network architecture.
So, this is "non-optimizal" because traffic has to hit the central anchor ? Is it not same as PS1 ? Please add few lines of text
Revise as follows:
Mobile networks have generally been evolving towards a flat
network. Centralized mobility management, which is non-optimal
with a flat network architecture, does not support this
evolution.
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PS3: Low scalability of centralized tunnel management and mobility
context maintenance
Setting up tunnels through a central anchor and maintaining
mobility context for each MN usually requires more concentrated
resources in a centralized design, thus reducing scalability.
Distributing the tunnel maintenance function and the mobility
context maintenance function among different network entities
with proper signaling protocol design can increase scalability.
Its not scalable because it requires lot of "concentrated resources" ? But, distributing them allows it to scale. Not very convincing argument
We can revise as follows:
PS3: Scalability of centralized tunnel management and mobility
context maintenance
Setting up tunnels through a central anchor and maintaining
mobility context for each MN usually requires more concentrated
resources in a centralized design, thus reducing scalability.
Distributing the tunnel maintenance function and the mobility
context maintenance function among different network entities
with proper signaling protocol design can avoid increasing the
concentrated resources with an increasing number of MNs.
PS4: Single point of failure and attack
Centralized anchoring designs may be more vulnerable to single
points of failures and attacks than a distributed system. The
impact of a successful attack on a system with centralized
mobility management can be far greater as well.
PS5: Unnecessary mobility support to nodes that do not need it
IP mobility support is not always required, and not every
parameter of mobility context is always used. For example,
some applications do not need a stable IP address during a
handover to maintain session continuity. Sometimes, the entire
application session runs while the terminal does not change the
point of attachment. Besides, some sessions, e.g. SIP-based
sessions, can handle mobility at the application layer and
hence do not need IP mobility support; it is then more
efficient to deactivate IP mobility support for such sessions.
PS5 is about enabling mobility support only to clients that need it ?
Yes.
PS5: Unnecessary mobility support to clients that do not need it
IP mobility support is usually provided to all MNs. Yet it is
not always required, and not every parameter of mobility
context is always used. For example, some applications do not
need a stable IP address during a handover to maintain session
continuity. Sometimes, the entire application session runs
while the terminal does not change the point of attachment.
Besides, some sessions, e.g. SIP-based sessions, can handle
mobility at the application layer and hence do not need IP
mobility support; it is then unnecessary to provide IP mobility
support for such sessions.
PS6: (Related problem) Mobility signaling overhead with peer-to-peer
communication
Wasting resources when mobility signaling (e.g., maintenance of
the tunnel, keep alive signaling, etc.) is not turned off for
peer-to-peer communication. Peer-to-peer communications have
particular traffic patterns that often do not benefit from
mobility support from the network. Thus, the associated
mobility support signaling (e.g., maintenance of the tunnel,
keep alive signaling, etc.) wastes network resources for no
application gain.
So, the problem is about signaling load in the network. You want to minimize the signaling load in the mobility network because of the Peer-to-Peer application traffic ? Ok.
Delete as shown above
PS7: (Related problem) Deployment with multiple mobility solutions
There are already many variants and extensions of MIP.
Deployment of new mobility management solutions can be
challenging, and debugging difficult, when they must co-exist
with solutions already in the field.
You mean to say, "protocols" or "solutions" ?
Both. A new solution may not need a new protocol whereas a given protocol can be deployed in different manners.
So, this is a section on "Problem Statement". Why is this talking about a requirement ?
Delete "must" which seem like a requirement.
There are already many variants and extensions of MIP.
Deployment of new mobility management solutions can be
challenging, and debugging difficult, when they co-exist with
solutions already deployed in the field.
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PS8: Duplicate multicast traffic
IP multicast distribution over architectures using IP mobility
solutions (e.g., [RFC6224]) may lead to convergence of
duplicated multicast subscriptions towards the downstream
tunnel entity (e.g. MAG in PMIPv6). Concretely, when
multicast subscription for individual mobile nodes is coupled
with mobility tunnels (e.g. PMIPv6 tunnel), duplicate
multicast subscription(s) is prone to be received through
different upstream paths. This problem may also exist or be
more severe in a distributed mobility environment.
5. Requirements
After comparing distributed mobility management against centralized
deployment in Section 3, this section identifies the following
requirements:
5.1. Distributed processing
REQ1: Distributed processing
IP mobility, network access and routing solutions provided by
DMM MUST enable distributed processing for mobility management
so that traffic can avoid traversing single mobility anchor
far from the optimal route.
Motivation: This requirement is motivated by current trends in
network evolution: (a) it is cost- and resource-effective to
cache and distribute content by combining distributed mobility
anchors with caching systems (e.g., CDN); (b) the
significantly larger number of mobile nodes and flows call for
improved scalability; (c) single points of failure are avoided
in a distributed system; (d) threats against centrally
deployed anchors, e.g., home agent and local mobility anchor,
are mitigated in a distributed system.
This requirement addresses the problems PS1, PS2, PS3, and PS4
described in Section 4.
5.2. Transparency to Upper Layers when needed
REQ2: Transparency to Upper Layers when needed
DMM solutions MUST provide transparent mobility support above
the IP layer when needed. Such transparency is needed, for
example, when, upon change of point of attachment to the
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network, an application flow cannot cope with a change in the
IP address. However, it is not always necessary to maintain a
stable home IP address or prefix for every application or at
all times for a mobile node.
Motivation: The motivation of this requirement is to enable
more efficient routing and more efficient use of network
resources by selecting an IP address or prefix according to
whether mobility support is needed and by not maintaining
context at the mobility anchor when there is no such need.
This requirement addresses the problem PS5 as well as the related
problem PS6 stated in Section 4.
5.3. IPv6 deployment
REQ3: IPv6 deployment
DMM solutions SHOULD target IPv6 as the primary deployment
environment and SHOULD NOT be tailored specifically to support
IPv4, in particular in situations where private IPv4 addresses
and/or NATs are used.
Motivation: This requirement conforms to the general
orientation of IETF work. DMM deployment is foreseen in mid-
to long-term horizon, when IPv6 is expected to be far more
common than today.
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
REQ4: Existing mobility protocols
A DMM solution SHOULD first consider reusing and extending
IETF-standardized protocols before specifying new protocols.
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.
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5.5. Co-existence
REQ5: Co-existence with deployed networks and hosts
The DMM solution MUST be able to co-exist with existing
network deployments and end hosts. For example, depending on
the environment in which DMM is deployed, DMM solutions may
need to be compatible with other deployed mobility protocols
or may need to co-exist with a network or mobile hosts/routers
that do not support DMM protocols. The mobile node may also
move between different access networks, where some of them may
support neither DMM nor another mobility protocol.
Furthermore, a DMM solution SHOULD work across different
networks, possibly operated as separate administrative
domains, when allowed by the trust relationship between them.
Motivation: (a) to preserve backwards compatibility so that
existing networks and hosts are not affected and continue to
function as usual, and (b) enable inter-domain operation if
desired.
This requirement addresses the related problem PS7 described in
Section 4.
5.6. Security considerations
REQ6: Security considerations
A DMM solution MUST not introduce new security risks or
amplify existing security risks against which the existing
security mechanisms/protocols cannot offer sufficient
protection.
Motivation: Various attacks such as impersonation, denial of
service, man-in-the-middle attacks, and so on, may be launched
in a DMM deployment. For instance, an illegitimate node may
attempt to access a network providing DMM. Another example is
that a malicious node can forge a number of signaling messages
thus redirecting traffic from its legitimate path.
Consequently, the specific node is under a denial of service
attack, whereas other nodes do not receive their traffic.
Accordingly, security mechanisms/protocols providing access
control, integrity, authentication, authorization,
confidentiality, etc. can be used to protect the DMM entities
as they are already used to protect against existing networks
and existing mobility protocols defined in IETF.
This requirement prevents a DMM solution from introducing
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uncontrollable 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 users.
5.7. Multicast
REQ7: Multicast considerations
DMM SHOULD consider multicast early so that solutions can be
developed not only to provide IP mobility support when it is
needed, but also to avoid network inefficiency issues in
multicast traffic delivery (such as duplicate multicast
subscriptions towards the downstream tunnel entities). The
multicast solutions should therefore avoid restricting the
management of all IP multicast traffic to a single host
through a dedicated (tunnel) interface on multicast-capable
access routers.
Motivation: Existing multicast deployment have been introduced
after completing the design of the reference mobility
protocol, then optimization and extensions have been followed
by "patching-up" procedure, thus leading to network
inefficiency and non-optimal routing. The multicast solutions
should therefore be required to consider efficiency nature in
multicast traffic delivery.
[Sri] Considering multicast at a design phase is not technical requirement for DMM.
What is "patching up" procedure ?
Revise as follows:
REQ7: Multicast considerations
DMM SHOULD enable multicast solutions to be developed to avoid
network inefficiency in multicast traffic delivery.
Motivation: Existing multicast deployment have been introduced
after completing the design of the reference mobility
protocol, often leading to network inefficiency and non-
optimal routing for the multicast traffic. Instead DMM should
consider multicast early so that the multicast solutions can
better consider efficiency nature in the multicast traffic
delivery (such as duplicate multicast subscriptions towards
the downstream tunnel entities). The multicast solutions
should then avoid restricting the management of all IP
multicast traffic to a single host through a dedicated
(tunnel) interface on multicast-capable access routers.
This requirement addresses the problems PS1 and PS8 described in
Section 4.
6. Security Considerations
Please refer to the discussion under Security requirement in Section
5.6.
7. IANA Considerations
None
8. Co-authors and Contributors
This problem statement document is a joint effort among the numerous
participants. Each individual has made significant contributions to
this work and have been listed as co-authors.
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9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
9.2. Informative References
[I-D.bhandari-dhc-class-based-prefix]
Bhandari, S., Halwasia, G., Gundavelli, S., Deng, H.,
Thiebaut, L., Korhonen, J., and I. Farrer, "DHCPv6 class
based prefix", draft-bhandari-dhc-class-based-prefix-05
(work in progress), July 2013.
[I-D.korhonen-6man-prefix-properties]
Korhonen, J., Patil, B., Gundavelli, S., Seite, P., and D.
Liu, "IPv6 Prefix Properties",
draft-korhonen-6man-prefix-properties-02 (work in
progress), July 2013.
[I-D.wakikawa-netext-pmip-cp-up-separation]
Wakikawa, R., Pazhyannur, R., and S. Gundavelli,
"Separation of Control and User Plane for Proxy Mobile
IPv6", draft-wakikawa-netext-pmip-cp-up-separation-00
(work in progress), July 2013.
[I-D.yokota-dmm-scenario]
Yokota, H., Seite, P., Demaria, E., and Z. Cao, "Use case
scenarios for Distributed Mobility Management",
draft-yokota-dmm-scenario-00 (work in progress),
October 2010.
[Paper-Distributed.Centralized.Mobility]
Bertin, P., Bonjour, S., and J-M. Bonnin, "A Distributed
or Centralized Mobility", Proceedings of Global
Communications Conference (GlobeCom), December 2009.
[Paper-Distributed.Dynamic.Mobility]
Bertin, P., Bonjour, S., and J-M. Bonnin, "A Distributed
Dynamic Mobility Management Scheme Designed for Flat IP
Architectures", Proceedings of 3rd International
Conference on New Technologies, Mobility and Security
(NTMS), 2008.
[Paper-Distributed.Mobility.MIP]
Chan, H., "Distributed Mobility Management with Mobile
IP", Proceedings of IEEE International Communication
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Conference (ICC) Workshop on Telecommunications: from
Research to Standards, June 2012.
[Paper-Distributed.Mobility.PMIP]
Chan, H., "Proxy Mobile IP with Distributed Mobility
Anchors", Proceedings of GlobeCom Workshop on Seamless
Wireless Mobility, December 2010.
[Paper-Distributed.Mobility.Review]
Chan, H., Yokota, H., Xie, J., Seite, P., and D. Liu,
"Distributed and Dynamic Mobility Management in Mobile
Internet: Current Approaches and Issues, Journal of
Communications, vol. 6, no. 1, pp. 4-15, Feb 2011.",
Proceedings of GlobeCom Workshop on Seamless Wireless
Mobility, February 2011.
[Paper-Distributed.Mobility.SAE]
Fisher, M., Anderson, F., Kopsel, A., Schafer, G., and M.
Schlager, "A Distributed IP Mobility Approach for 3G SAE",
Proceedings of the 19th International Symposium on
Personal, Indoor and Mobile Radio Communications (PIMRC),
2008.
[Paper-Locating.User]
Kirby, G., "Locating the User", Communication
International, 1995.
[Paper-Migrating.Home.Agents]
Wakikawa, R., Valadon, G., and J. Murai, "Migrating Home
Agents Towards Internet-scale Mobility Deployments",
Proceedings of the ACM 2nd CoNEXT Conference on Future
Networking Technologies, December 2006.
[Paper-Mobile.Data.Offloading]
Lee, K., Lee, J., Yi, Y., Rhee, I., and S. Chong, "Mobile
Data Offloading: How Much Can WiFi Deliver?", SIGCOMM
2010, 2010.
[RFC3753] Manner, J. and M. Kojo, "Mobility Related Terminology",
RFC 3753, June 2004.
[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.
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[RFC5944] Perkins, C., "IP Mobility Support for IPv4, Revised",
RFC 5944, November 2010.
[RFC6224] Schmidt, T., Waehlisch, M., and S. Krishnan, "Base
Deployment for Multicast Listener Support in Proxy Mobile
IPv6 (PMIPv6) Domains", RFC 6224, April 2011.
[RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support
in IPv6", RFC 6275, July 2011.
[RFC6301] Zhu, Z., Wakikawa, R., and L. Zhang, "A Survey of Mobility
Support in the Internet", RFC 6301, July 2011.
[RFC6705] Krishnan, S., Koodli, R., Loureiro, P., Wu, Q., and A.
Dutta, "Localized Routing for Proxy Mobile IPv6",
RFC 6705, September 2012.
[RFC6909] Gundavelli, S., Zhou, X., Korhonen, J., Feige, G., and R.
Koodli, "IPv4 Traffic Offload Selector Option for Proxy
Mobile IPv6", RFC 6909, April 2013.
[TS.23.401]
3GPP, "General Packet Radio Service (GPRS) enhancements
for Evolved Universal Terrestrial Radio Access Network
(E-UTRAN) access", 3GPP TR 23.401 10.10.0, March 2013.
[TS.29303]
3GPP, "Domain Name System Procedures; Stage 3", 3GPP
TR 23.303 11.2.0, September 2012.
Authors' Addresses
H Anthony Chan (editor)
Huawei Technologies (more co-authors on P. 17)
5340 Legacy Dr. Building 3, Plano, TX 75024, USA
Email: [email protected]<mailto:[email protected]>
Dapeng Liu
China Mobile
Unit2, 28 Xuanwumenxi Ave, Xuanwu District, Beijing 100053, China
Email: [email protected]<mailto:[email protected]>
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Pierrick Seite
Orange
4, rue du Clos Courtel, BP 91226, Cesson-Sevigne 35512, France
Email: [email protected]<mailto:[email protected]>
Hidetoshi Yokota
KDDI Lab
2-1-15 Ohara, Fujimino, Saitama, 356-8502 Japan
Email: [email protected]<mailto:[email protected]>
Jouni Korhonen
Renesas Mobile
Porkkalankatu 24, FIN-00180 Helsinki, Finland
Email: [email protected]<mailto:[email protected]>
-
Charles E. Perkins
Huawei Technologies
Email: [email protected]<mailto:[email protected]>
-
Melia Telemaco
Alcatel-Lucent Bell Labs
Email: [email protected]<mailto:[email protected]>
-
Elena Demaria
Telecom Italia
via G. Reiss Romoli, 274, TORINO, 10148, Italy
Email: [email protected]<mailto:[email protected]>
-
Jong-Hyouk Lee
Sangmyung University
Email: [email protected]<mailto:[email protected]>
-
Kostas Pentikousis
EICT GmbH
Email: [email protected]<mailto:[email protected]>
-
Tricci So
ZTE
Email: [email protected]<mailto:[email protected]>
-
Carlos J. Bernardos
Universidad Carlos III de Madrid
Av. Universidad, 30, Leganes, Madrid 28911, Spain
Email: [email protected]<mailto:[email protected]>
-
Peter McCann
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Huawei Technologies
Email: [email protected]<mailto:[email protected]>
-
Seok Joo Koh
Kyungpook National University, Korea
Email: [email protected]<mailto:[email protected]>
-
Wen Luo
ZTE
No.68, Zijinhua RD,Yuhuatai District, Nanjing, Jiangsu 210012, China
Email: [email protected]<mailto:[email protected]>
-
Sri Gundavelli
Cisco
[email protected]<mailto:[email protected]>
-
Marco Liebsch
NEC Laboratories Europe
Email: [email protected]<mailto:[email protected]>
-
Carl Williams
MCSR Labs
Email: [email protected]<mailto:[email protected]>
-
Seil Jeon
Instituto de Telecomunicacoes, Aveiro
Email: [email protected]<mailto:[email protected]>
-
Sergio Figueiredo
Universidade de Aveiro
Email: [email protected]<mailto:[email protected]>
-
Stig Venaas
Email: [email protected]<mailto:[email protected]>
-
Luis Miguel Contreras Murillo
Telefonica I+D
Email: [email protected]<mailto:[email protected]>
-
Juan Carlos Zuniga
InterDigital
Email: [email protected]<mailto:[email protected]>
-
Alexandru Petrescu
Email: [email protected]<mailto:[email protected]>
-
Georgios Karagiannis
University of Twente
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Email: [email protected]<mailto:[email protected]>
-
Julien Laganier
Juniper
[email protected]<mailto:[email protected]>
-
Wassim Michel Haddad
Ericsson
[email protected]<mailto:[email protected]>
-
Dirk von Hugo
Deutsche Telekom Laboratories
[email protected]<mailto:[email protected]>
-
Ahmad Muhanna
Award Solutions
[email protected]<mailto:[email protected]>
-
Byoung-Jo Kim
ATT Labs
[email protected]<mailto:[email protected]>
-
Hassan Ali-Ahmad
Orange
[email protected]<mailto:[email protected]>
-
Alper Yegin
Samsung
[email protected]<mailto:[email protected]>
-
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