draft-ietf-dmm-best-practices-gap-analysis-03.txt   draft-ietf-dmm-best-practices-gap-analysis-04.txt 
DMM D. Liu, Ed. DMM D. Liu, Ed.
Internet-Draft China Mobile Internet-Draft China Mobile
Intended status: Informational JC. Zuniga, Ed. Intended status: Informational JC. Zuniga, Ed.
Expires: August 18, 2014 InterDigital Expires: November 26, 2014 InterDigital
P. Seite P. Seite
Orange Orange
H. Chan H. Chan
Huawei Technologies Huawei Technologies
CJ. Bernardos CJ. Bernardos
UC3M UC3M
February 14, 2014 May 25, 2014
Distributed Mobility Management: Current practices and gap analysis Distributed Mobility Management: Current practices and gap analysis
draft-ietf-dmm-best-practices-gap-analysis-03 draft-ietf-dmm-best-practices-gap-analysis-04
Abstract Abstract
The present document analyzes deployment practices of existing IP The present document analyzes deployment practices of existing IP
mobility protocols in a distributed mobility management environment. mobility protocols in a distributed mobility management environment.
It then identifies existing limitations when compared to the It then identifies existing limitations when compared to the
requirements defined for a distributed mobility management solution. requirements defined for a distributed mobility management solution.
Status of This Memo Status of This Memo
skipping to change at page 1, line 40 skipping to change at page 1, line 39
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 August 18, 2014. This Internet-Draft will expire on November 26, 2014.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 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
skipping to change at page 2, line 18 skipping to change at page 2, line 18
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 . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Functions of existing mobility protocols . . . . . . . . . . 3 3. Functions of existing mobility protocols . . . . . . . . . . 3
4. DMM practices . . . . . . . . . . . . . . . . . . . . . . . . 5 4. DMM practices . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Assumptions . . . . . . . . . . . . . . . . . . . . . . . 5 4.1. Assumptions . . . . . . . . . . . . . . . . . . . . . . . 5
4.2. IP flat wireless network . . . . . . . . . . . . . . . . 5 4.2. IP flat wireless network . . . . . . . . . . . . . . . . 6
4.2.1. Host-based IP DMM practices . . . . . . . . . . . . . 7 4.2.1. Host-based IP DMM practices . . . . . . . . . . . . . 7
4.2.2. Network-based IP DMM practices . . . . . . . . . . . 11 4.2.2. Network-based IP DMM practices . . . . . . . . . . . 12
4.3. 3GPP network flattening approaches . . . . . . . . . . . 13 4.3. 3GPP network flattening approaches . . . . . . . . . . . 14
5. Gap analysis . . . . . . . . . . . . . . . . . . . . . . . . 16 5. Gap analysis . . . . . . . . . . . . . . . . . . . . . . . . 17
5.1. Distributed processing - REQ1 . . . . . . . . . . . . . . 16 5.1. Distributed processing - REQ1 . . . . . . . . . . . . . . 17
5.2. Bypassable network-layer mobility support - REQ2 . . . . 18 5.2. On-demand network-layer mobility support - REQ2 . . . . . 19
5.3. IPv6 deployment - REQ3 . . . . . . . . . . . . . . . . . 19 5.3. IPv6 deployment - REQ3 . . . . . . . . . . . . . . . . . 20
5.4. Existing mobility protocols - REQ4 . . . . . . . . . . . 19 5.4. Existing mobility protocols - REQ4 . . . . . . . . . . . 21
5.5. Co-existence - REQ5 . . . . . . . . . . . . . . . . . . . 19 5.5. Co-existence - REQ5 . . . . . . . . . . . . . . . . . . . 21
5.6. Security considerations - REQ6 . . . . . . . . . . . . . 20 5.6. Security considerations - REQ6 . . . . . . . . . . . . . 21
5.7. Multicast - REQ7 . . . . . . . . . . . . . . . . . . . . 20 5.7. Multicast - REQ7 . . . . . . . . . . . . . . . . . . . . 21
5.8. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 21 5.8. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 22
6. Security Considerations . . . . . . . . . . . . . . . . . . . 21 6. Security Considerations . . . . . . . . . . . . . . . . . . . 23
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 21 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 23
8.1. Normative References . . . . . . . . . . . . . . . . . . 22 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 23
8.2. Informative References . . . . . . . . . . . . . . . . . 22 9.1. Normative References . . . . . . . . . . . . . . . . . . 23
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25 9.2. Informative References . . . . . . . . . . . . . . . . . 24
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27
1. Introduction 1. Introduction
The distributed mobility management (DMM) WG has studied the problems The distributed mobility management (DMM) WG has studied the problems
of centralized deployment of mobility management protocols and of centralized deployment of mobility management protocols and
specified the DMM requirements [I-D.ietf-dmm-requirements]. This specified the DMM requirements [I-D.ietf-dmm-requirements]. This
document investigates whether it is feasible to deploy current IP document investigates whether it is feasible to deploy current IP
mobility protocols in a DMM scenario in a way that can fulfill the mobility protocols in a DMM scenario in a way that can fulfill the
requirements. It discusses current deployment practices of existing requirements. It discusses current deployment practices of existing
mobility protocols in a distributed mobility management environment mobility protocols and identifies the limitations (gaps) in these
and identifies the limitations (gaps) in these practices with respect practices from the standpoint of satisfying DMM requirements, as
to the DMM functionality, as defined in [I-D.ietf-dmm-requirements]. defined in [I-D.ietf-dmm-requirements].
The rest of this document is organized as follows. Section 3 The rest of this document is organized as follows. Section 3
analyzes existing IP mobility protocols by examining their functions analyzes existing IP mobility protocols by examining their functions
and how these functions can be configured and used to work in a DMM and how these functions can be configured and used to work in a DMM
environment. Section 4 presents the current practices of IP flat environment. Section 4 presents the current practices of IP wireless
wireless networks and 3GPP architectures. Both network- and host- networks and 3GPP architectures. Both network-based and host-based
based mobility protocols are considered. Section 5 presents the gap mobility protocols are considered. Section 5 presents the gap
analysis with respect to the current practices. analysis with respect to the current practices.
2. Terminology 2. Terminology
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 [RFC2119]. document are to be interpreted as described in [RFC2119].
All general mobility-related terms and their acronyms used in this All general mobility-related terms and their acronyms used in this
document are to be interpreted as defined in the Mobile IPv6 base document are to be interpreted as defined in the Mobile IPv6 base
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(CN), home agent (HA), local mobility anchor (LMA), and mobile access (CN), home agent (HA), local mobility anchor (LMA), and mobile access
gateway (MAG). gateway (MAG).
In addition, this document also introduces some definitions of IP In addition, this document also introduces some definitions of IP
mobility functions in Section 3. mobility functions in Section 3.
In this document there are also references to a "distributed mobility In this document there are also references to a "distributed mobility
management environment". By this term, we refer to a scenario in management environment". By this term, we refer to a scenario in
which the IP mobility, access network and routing solutions allow for which the IP mobility, access network and routing solutions allow for
setting up IP networks so that traffic is distributed in an optimal setting up IP networks so that traffic is distributed in an optimal
way, without relying on centrally deployed anchors to manage IP way, without the reliance on centrally deployed anchors to manage IP
mobility sessions. mobility sessions.
3. Functions of existing mobility protocols 3. Functions of existing mobility protocols
The host-based Mobile IPv6 [RFC6275] and its network-based extension, Host-based Mobile IPv6 [RFC6275], its network-based extension, PMIPv6
PMIPv6 [RFC5213], are both logically centralized mobility management [RFC5213], and HMIPv6 [RFC5380] are all logically centralized
approaches addressing primarily hierarchical mobile networks. mobility management approaches that primarily address hierarchical
Although they are centralized approaches, they have important mobile networks. Although they are centralized approaches, they have
mobility management functions resulting from years of extensive work important mobility management functions resulting from years of
to develop and to extend these functions. It is therefore useful to extensive work to develop and to extend these functions. It is
take these existing functions and examine them in a DMM scenario in therefore useful to take these existing functions and examine them in
order to understand how to deploy the existing mobility protocols in a DMM scenario in order to understand how to deploy the existing
a distributed mobility management environment. mobility protocols to provide distributed mobility management.
The main mobility management functions of MIPv6, PMIPv6, and HMIPv6 The main mobility management functions of MIPv6, PMIPv6, and HMIPv6
are the following: are the following:
1. Anchoring function (AF): allocation to a mobile node of an IP 1. Anchoring function (AF): allocation to a mobile node of an IP
address/prefix (e.g., a Home Address or Home Network Prefix) address (a Home Address (HoA)) or prefix (a Home Network Prefix
topologically anchored by the delegating node (i.e., the anchor (HNP)) topologically anchored by the advertising node (i.e., the
node is able to advertise a connected route into the routing anchor node is able to advertise a connected route into the
infrastructure for the delegated IP prefixes). It is a control routing infrastructure for the allocated IP prefixes). It is a
plane function. control plane function.
2. Internetwork Location Management (LM) function: managing and 2. Internetwork Location Management (LM) function: managing and
keeping track of the internetwork location of an MN. The keeping track of the internetwork location of an MN. The
location information may be a mapping of the IP delegated address location information may be a mapping of the IP advertised
/prefix (e.g., HoA or HNP) to the IP routing address of the MN or address/prefix (e.g., HoA or HNP) to the IP routing address of
of a node that can forward packets destined to the MN. It is a the MN or of a node that can forward packets destined to the MN.
control plane function. It is a control plane function.
In a client-server model of the system, location query and update In a client-server protocol model, location query and update
messages may be exchanged between the client (LMc) and the server messages may be exchanged between the client (LMc) and the server
(LMs). (LMs).
Optionally, one (or more) proxy may exist between the LMs and the 3. Forwarding Management (FM) function: packet interception and
LMc, i.e., LMs-proxy-LMc. Then, to the LMs, the proxy behaves forwarding to/from the IP address/prefix assigned to the MN,
like the LMc; to the LMc, the proxy behaves like the LMs.
3. Routing management (RM) function: packet interception and
forwarding to/from the IP address/prefix delegated to the MN,
based on the internetwork location information, either to the based on the internetwork location information, either to the
destination or to some other network element that knows how to destination or to some other network element that knows how to
forward the packets to their destination. forward the packets to their destination.
RM may optionally be split into the control plane (RM-CP) and FM may optionally be split into the control plane (FM-CP) and
data plane (RM-DP). data plane (FM-DP).
In Mobile IPv6 [RFC6275], the home agent (HA) typically provides the In Mobile IPv6, the home agent (HA) typically provides the anchoring
anchoring function (AF); the location management server (LMs) is at function (AF); the location management server (LMs) is at the HA
the HA while the location management client (LMc) is at the MN; the while the location management client (LMc) is at the MN; the
routing management (RM) function is both ends of tunneling at the HA forwarding management (FM) function is both ends of tunneling at the
and the MN. HA and the MN.
In Proxy Mobile IPv6 [RFC5213], the Local Mobility Anchor (LMA) In Proxy Mobile IPv6, the Local Mobility Anchor (LMA) provides the
provides the anchoring function (AF); the location management server anchoring function (AF); the location management server (LMs) is at
(LMs) is at the LMA while the location management client (LMc) is at the LMA while the location management client (LMc) is at the mobile
the mobile access gateway (MAG); the routing management (RM) function access gateway (MAG); the forwarding management (FM) function is both
is both ends of tunneling at the HA and the MAG. ends of tunneling at the HA and the MAG.
In Hirarchical mobile IPv6 (HMIPv6) [RFC5380], a location management In Hirarchical mobile IPv6 (HMIPv6) [RFC5380], the mobility anchor
proxy is at the mobility anchor point (MAP) to proxy between the LMs point (MAP) serves as a location management aggregator between the
at the LMA and the LMc at the MN. The MAP also has RM funtion to LMs at the HA and the LMc at the MN. The MAP also has the FM
enable tunneling between LMA and itself as well as tunneling between function to enable tunneling between HA and itself as well as
MN and itself. tunneling between MN and itself.
4. DMM practices 4. DMM practices
This section documents deployment practices of existing mobility This section documents deployment practices of existing mobility
protocols in a distributed mobility management environment. This protocols to satisfy distributed mobility management requirements.
description is divided into two main families of network This description considers both IP wireless (e.g., evolved Wi-Fi
architectures: i) IP flat wireless networks (e.g., evolved Wi-Fi hotspots) and 3GPP Architecture flattening approaches(i.e. fewer
hotspots) and, ii) 3GPP network flattening approaches. levels of routing hierarchy introduced into the data path by the
mobility management system).
While describing the current DMM practices, references to the generic While describing the current DMM practices, references to the generic
mobility management functions described in Section 3 are provided, as mobility management functions described in Section 3 are provided, as
well as some initial hints on the identified gaps with respect to the well as some initial hints on the identified gaps with respect to the
DMM requirements documented in [I-D.ietf-dmm-requirements]. DMM requirements documented in [I-D.ietf-dmm-requirements].
4.1. Assumptions 4.1. Assumptions
There are many different approaches that can be considered to There are many different approaches that can be considered to
implement and deploy a distributed anchoring and mobility solution. implement and deploy a distributed anchoring and mobility solution.
The focus of the gap analysis is on current mobile network The focus of the gap analysis is on certain current mobile network
architectures and standardized IP mobility solutions, considering any architectures and standardized IP mobility solutions, considering any
kind of deployment options which do not violate the original protocol kind of deployment options which do not violate the original protocol
specifications. In order to limit the scope of our analysis of specifications. In order to limit the scope of our analysis of DMM
current DMM practices, we consider the following list of technical practices, we consider the following list of technical assumptions:
assumptions:
1. Both host- and network-based solutions SHOULD be considered. 1. Both host-based and network-based solutions should be considered.
2. Solutions SHOULD allow selecting and using the most appropriate 2. Solutions should allow selecting and using the most appropriate
IP anchor among a set of available ones. IP anchor among a set of available candidates.
3. Mobility management SHOULD be realized by the preservation of the 3. Mobility management should be realized by the preservation of the
IP address across the different points of attachment (i.e., IP address across the different points of attachment (i.e.,
provision of IP address continuity). provision of IP address continuity). This is in contrast to
certain transport-layer based approaches such as SCTP or
application-layer mobility.
Applications which can cope with changes in the MN's IP address do Applications which can cope with changes in the MN's IP address do
not depend on IP mobility management protocols such as DMM. not depend on IP mobility management protocols such as DMM.
Typically, a connection manager together with the operating system Typically, a connection manager together with the operating system
will configure the source address selection mechanism of the IP will configure the source address selection mechanism of the IP
stack. This might involve identifying application capabilities and stack. This might involve identifying application capabilities and
triggering the mobility support accordingly. Further considerations triggering the mobility support accordingly. Further considerations
on application management and source address selection are out of the on application management and source address selection are out of the
scope of this document. scope of this document, but the reader might consult [RFC-
SourceAddrSelection].
4.2. IP flat wireless network 4.2. IP flat wireless network
This section focuses on common IP wireless network architectures and This section focuses on common IP wireless network architectures and
how they can be flattened from an IP mobility and anchoring point of how they can be flattened from an IP mobility and anchoring point of
view using common and standardized protocols. We take Wi-Fi as an view using common and standardized protocols. We take Wi-Fi as an
exemplary wireless technology, since it is widely known and deployed useful wireless technology, since it is widely known and deployed
nowadays. Some representative examples of Wi-Fi deployment nowadays. Some representative examples of Wi-Fi deployment
architectures are depicted in Figure 1. architectures are depicted in Figure 1.
+-------------+ _----_ +-------------+ _----_
+---+ | Access | _( )_ +---+ | Access | _( )_
|AAA|. . . . . . | Aggregation |----------( Internet ) |AAA|. . . . . . | Aggregation |----------( Internet )
+---+ | Gateway | (_ _) +---+ | Gateway | (_ _)
+-------------+ '----' +-------------+ '----'
| | | | | |
| | +-------------+ | | +-------------+
| | | | | |
| | +-----+ | | +-----+
+---------------+ | | AR | +---------------+ | | AR |
| | +--+--+ | | +--+--+
+-----+ +-----+ *----+----* +-----+ +-----+ *----+----*
| RG | | WLC | ( LAN ) | RG | | WLC | ( LAN )
+-----+ +-----+ *---------* +-----+ +-----+ *---------*
. / \ / \ . / \ / \
/ \ +-----+ +-----+ +-----+ +-----+ / \ +-----+ +-----+ +-----+ +-----+
MN MN |Wi-Fi| |Wi-Fi| |Wi-Fi| |Wi-Fi| MN MN |Wi-Fi| |Wi-Fi| |Wi-Fi| |Wi-Fi|
| AP | | AP | | AP | | AP | | AP | | AP | | AP | | AP |
+-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+ +-----+
. . . .
/ \ / \ / \ / \
MN MN MN MN MN MN MN MN
Figure 1: IP Wi-Fi network architectures Figure 1: IP Wi-Fi network architectures
In the figure, three typical deployment options are shown In the figure, three typical deployment options are shown
[I-D.gundavelli-v6ops-community-wifi-svcs]. On the left hand side of [I-D.gundavelli-v6ops-community-wifi-svcs]. On the left hand side of
the figure, mobile nodes directly connect to a Residential Gateway the figure, mobile nodes directly connect to a Residential Gateway
(RG) which is a network device at the customer premises and provides (RG) which is a network device at the customer premises and provides
both wireless layer-2 access connectivity (i.e., it hosts the 802.11 both wireless layer-2 access connectivity (i.e., it hosts the 802.11
Access Point function) and layer-3 routing functions. In the middle Access Point function) and layer-3 routing functions. In the middle
of the figure, mobile nodes connect to Wi-Fi Access Points (APs) that of the figure, mobile nodes connect to Wi-Fi Access Points (APs) that
are managed by a WLAN Controller (WLC), which performs radio resource are managed by a WLAN Controller (WLC), which performs radio resource
management on the APs, system-wide mobility policy enforcement and management on the APs, domain-wide mobility policy enforcement and
centralized forwarding function for the user traffic. The WLC could centralized forwarding function for the user traffic. The WLC could
also implement layer-3 routing functions, or attach to an access also implement layer-3 routing functions, or attach to an access
router (AR). Last, on the right-hand side of the figure, access router (AR). Last, on the right-hand side of the figure, access
points are directly connected to an access router. This can also be points are directly connected to an access router. This can also be
used as a generic connectivity model. used as a generic connectivity model.
In some network architectures, such as the evolved Wi-Fi hotspot, IP mobility protocols can be used to provide inter-access mobility
operators might make use of IP mobility protocols to provide mobility support to users, e.g. handover from Wi-Fi to cellular access. Two
support to users, for example to allow connecting the IP Wi-Fi kinds of protocols can be used: Proxy Mobile IPv6 [RFC5213] or Mobile
network to a mobile operator core and support roaming between WLAN IPv6 [RFC5555], with the mobility anchor (e.g., local mobility anchor
and 3GPP accesses. Two main protocols can be used: Proxy Mobile IPv6 or home agent) role typically being played by the edge router of the
mobile network [SDO-3GPP.23.402].
[RFC5213] or Mobile IPv6 [RFC6275], [RFC5555], with the anchor (e.g.,
local mobility anchor or home agent) role typically being played by
the Access Aggregation Gateway or even by an entity placed in the
mobile operator's core network.
Although this section has adopted the example of Wi-Fi networks, Although this section has made use of the example of Wi-Fi networks,
there are other IP flat wireless network architectures specified, there are other IP flat wireless network architectures specified,
such as WiMAX [IEEE.802-16.2009], which integrates both host and such as WiMAX [IEEE.802-16.2009], which integrates both host and
network-based IP mobility functionality. network-based IP mobility functionality.
Existing IP mobility protocols can also be deployed in a more Existing IP mobility protocols can also be deployed in a more
flattened manner, so that the anchoring and access aggregation flattened manner, so that the anchoring and access aggregation
functions are distributed. We next describe several practices for functions are distributed. We next describe several practices for
the deployment of existing mobility protocols in a distributed the deployment of existing mobility protocols in a distributed
mobility management environment. The analysis in this section is mobility management environment. The analysis in this section is
limited to protocol solutions based on existing IP mobility limited to protocol solutions based on existing IP mobility
protocols, either host- or network-based, such as Mobile IPv6 protocols, either host-based or network-based, such as Mobile IPv6
[RFC6275], [RFC5555], Proxy Mobile IPv6 [RFC5213], [RFC5844] and NEMO [RFC6275], [RFC5555], Proxy Mobile IPv6 [RFC5213], [RFC5844] and NEMO
[RFC3963]. Extensions to these base protocol solutions are also [RFC3963]. Extensions to these base protocol solutions are also
considered. We pay special attention to how to efficiently select considered. The analysis is divided into two parts: host-based and
the source address (care-of-addresses versus home addresses) for network-based practices.
different types of communications. The analysis is divided into two
parts: host- and network-based practices.
4.2.1. Host-based IP DMM practices 4.2.1. Host-based IP DMM practices
Mobile IPv6 (MIPv6) [RFC6275] and its extension to support mobile Mobile IPv6 (MIPv6) [RFC6275] and its extension to support mobile
networks, the NEMO Basic Support protocol (hereafter, simply referred networks, the NEMO Basic Support protocol (hereafter, simply referred
to as NEMO) [RFC3963] are well-known host-based IP mobility to as NEMO) [RFC3963] are well-known host-based IP mobility
protocols. They heavily rely on the function of the Home Agent (HA), protocols. They depend upon the function of the Home Agent (HA), a
a centralized anchor, to provide mobile nodes (hosts and routers) centralized anchor, to provide mobile nodes (hosts and routers) with
with mobility support. In these approaches, the home agent typically mobility support. In these approaches, the home agent typically
provides the anchoring function (AF), Routing management (RM), and provides the anchoring function (AF), forwarding management (FM), and
Internetwork Location Management server (LMs) functions. The mobile Internetwork Location Management server (LMs) functions. The mobile
node possesses the Location management client (LMc) function and the node possesses the Location management client (LMc) function and the
RM function to enable tunneling between HA and itself. We next FM function to enable tunneling between HA and itself. We next
describe some practices on how MIPv6/NEMO and several additional describe some practices that show how MIPv6/NEMO and several other
protocol extensions can be deployed in a distributed mobility protocol extensions can be deployed in a distributed mobility
management environment. management environment.
One approach to distribute the anchors can be to deploy several HAs One approach to distribute the anchors can be to deploy several HAs
(as shown in Figure 2), and assign the topologically closest anchor (as shown in Figure 2), and assign the topologically closest anchor
to each MN [RFC4640], [RFC5026], [RFC6611]. In the example shown in to each MN [RFC4640], [RFC5026], [RFC6611]. In the example shown in
Figure 2, MN1 is assigned HA1 (and a home address anchored by HA1), Figure 2, MN1 is assigned HA1 (and a home address anchored by HA1),
while MN2 is assigned HA2. Note that MIPv6/NEMO specifications do while MN2 is assigned HA2. Note that MIPv6/NEMO specifications do
not prevent the simultaneous use of multiple home agents by a single not prevent the simultaneous use of multiple home agents by a single
mobile node. This deployment model could be exploited by a mobile mobile node. This deployment model could be exploited by a mobile
node to meet assumption #4 of Section 4.1 and use several anchors at node to meet assumption #4 of Section 4.1 and use several anchors at
the same time, each of them anchoring IP flows initiated at a the same time, each of them anchoring IP flows initiated at a
different point of attachment. However there is no mechanism different point of attachment. However there is no mechanism
specified by IETF to enable an efficient dynamic discovery of specified by IETF to enable an efficient dynamic discovery of
available anchors and the selection of the most suitable one. Note available anchors and the selection of the most suitable one. Note
that some of these mechanisms have been defined outside IETF (e.g., that some of these mechanisms [SDO-3GPP.23.402] have been defined
3GPP). outside IETF.
<- INTERNET -> <- HOME NETWORK -> <---- ACCESS NETWORK ----> <- INTERNET -> <- HOME NETWORK -> <---- ACCESS NETWORK ---->
------- ------- ------- -------
| CN1 | ------- | AR1 |-(o) zzzz (o) | CN1 | ------- | AR1 |-(o) zzzz (o)
------- | HA1 | ------- | ------- | HA1 | ------- |
------- (MN1 anchored at HA1) ------- ------- (MN1 anchored at HA1) -------
------- | MN1 | ------- | MN1 |
| AR2 |-(o) ------- | AR2 |-(o) -------
------- -------
------- -------
skipping to change at page 9, line 8 skipping to change at page 9, line 8
the direct path between them. Using the example shown in Figure 2, the direct path between them. Using the example shown in Figure 2,
MN1 is using BT mode with CN1 and MN2 is in RO mode with CN2. MN1 is using BT mode with CN1 and MN2 is in RO mode with CN2.
However, the RO mode has several drawbacks: However, the RO mode has several drawbacks:
o The RO mode is only supported by Mobile IPv6. There is no route o The RO mode is only supported by Mobile IPv6. There is no route
optimization support standardized for the NEMO protocol because of optimization support standardized for the NEMO protocol because of
the security problems posed by extending return routability tests the security problems posed by extending return routability tests
for prefixes, although many different solutions have been proposed for prefixes, although many different solutions have been proposed
[RFC4889]. [RFC4889].
o The RO mode requires additional signaling, which adds some o The RO mode requires signaling that adds some protocol overhead.
protocol overhead.
o The signaling required to enable RO involves the home agent and is o The signaling required to enable RO involves the home agent and is
repeated periodically for security reasons [RFC4225]. This repeated periodically for security reasons [RFC4225] and, thus,
basically means that the HA remains a single point of failure, the HA remains a single point of failure.
because the Mobile IPv6 RO mode does not mean HA-less operation.
o The RO mode requires additional support from the correspondent o The RO mode requires support from the correspondent node (CN).
node (CN).
Notwithstanding these considerations, the RO mode does offer the Notwithstanding these considerations, the RO mode does offer the
possibility of substantially reducing traffic through the Home Agent, possibility of substantially reducing traffic through the Home Agent,
in cases when it can be supported by the relevant correspondent in cases when it can be supported by the relevant correspondent
nodes. Note that a mobile node can also use its CoA directly nodes. Note that a mobile node can also use its CoA directly
[RFC5014] when communicating with CNs on the same link or anywhere in [RFC5014] when communicating with CNs on the same link or anywhere in
the Internet, although no session continuity support would be the Internet, although no session continuity support would be
provided by the IP stack in this case. provided by the IP stack in this case.
Hierarchical Mobile IPv6 (HMIPv6) [RFC5380] (as shown in Figure 3), Hierarchical Mobile IPv6 (HMIPv6) [RFC5380] (as shown in Figure 3),
is another host-based IP mobility extension which can be considered is another host-based IP mobility extension which can be considered
as a complement to provide a less centralized mobility deployment. as a complement to provide a less centralized mobility deployment.
It allows reducing the amount of mobility signaling as well as It allows reducing the amount of mobility signaling as well as
improving the overall handover performance of Mobile IPv6 by improving the overall handover performance of Mobile IPv6 by
introducing a new hierarchy level to handle local mobility. The introducing a new hierarchy level to handle local mobility. The
Mobility Anchor Point (MAP) entity is introduced as a local mobility Mobility Anchor Point (MAP) entity is introduced as a local mobility
handling node deployed closer to the mobile node. It provides LM handling node deployed closer to the mobile node. It provides LM
proxy function between the LM server (LMs) at the HA and the LM intermediary function between the LM server (LMs) at the HA and the
client (LMc) at the MN. It also possess RM function to tunnel with LM client (LMc) at the MN. It also performs the FM function using
the HA and also to tunnel with the MN. tunneling with the HA and also to tunnel with the MN.
<- INTERNET -> <- HOME NETWORK -> <------- ACCESS NETWORK -------> <- INTERNET -> <- HOME NETWORK -> <------- ACCESS NETWORK ------->
----- -----
/|AR1|-(o) zz (o) /|AR1|-(o) zz (o)
-------- / ----- | -------- / ----- |
| MAP1 |< ------- | MAP1 |< -------
-------- \ ----- | MN1 | -------- \ ----- | MN1 |
------- \|AR2| ------- ------- \|AR2| -------
| CN1 | ----- HoA anchored | CN1 | ----- HoA anchored
------- ----- at HA1 ------- ----- at HA1
skipping to change at page 10, line 23 skipping to change at page 10, line 37
CN1 CN2 HA1 MAP1 AR1 MN1 CN1 CN2 HA1 MAP1 AR1 MN1
| | | | ________|__________ | | | | | ________|__________ |
|<------------------>|<==============>|<________+__________>| HoA |<------------------>|<==============>|<________+__________>| HoA
| | | | | | | | | | | |
| |<-------------------------->|<===================>| RCoA | |<-------------------------->|<===================>| RCoA
| | | | | | | | | | | |
Figure 3: Hierarchical Mobile IPv6 Figure 3: Hierarchical Mobile IPv6
When HMIPv6 is used, the MN has two different temporal addresses: the When HMIPv6 is used, the MN has two different temporary addresses:
Regional Care-of Address (RCoA) and the Local Care-of Address (LCoA). the Regional Care-of Address (RCoA) and the Local Care-of Address
The RCoA is anchored at one MAP, that plays the role of local home (LCoA). The RCoA is anchored at one MAP, that plays the role of
agent, while the LCoA is anchored at the access router level. The local home agent, while the LCoA is anchored at the access router
mobile node uses the RCoA as the CoA signaled to its home agent. level. The mobile node uses the RCoA as the CoA signaled to its home
Therefore, while roaming within a local domain handled by the same agent. Therefore, while roaming within a local domain handled by the
MAP, the mobile node does not need to update its home agent (i.e., same MAP, the mobile node does not need to update its home agent
the mobile node does not change its RCoA). (i.e., the mobile node does not change its RCoA).
The use of HMIPv6 allows achieving some form of route optimization, The use of HMIPv6 enables some form of route optimization, since a
since a mobile node may decide to directly use the RCoA as source mobile node may decide to directly use the RCoA as source address for
address for a communication with a given correspondent node, notably a communication with a given correspondent node, particularly if the
if the MN does not expect to move outside the local domain during the MN does not expect to move outside the local domain during the
lifetime of the communication. This can be seen as a potential DMM lifetime of the communication. This can be seen as a potential DMM
mode of operation. In the example shown in Figure 3, MN1 is using mode of operation. In the example shown in Figure 3, MN1 is using
its global HoA to communicate with CN1, while it is using its RCoA to its global HoA to communicate with CN1, while it is using its RCoA to
communicate with CN2. communicate with CN2.
Additionally, a local domain might have several MAPs deployed, Furthermore, a local domain might have several MAPs deployed,
enabling therefore a different kind of HMIPv6 deployments (e.g., flat enabling therefore a different kind of HMIPv6 deployments (e.g., flat
and distributed). The HMIPv6 specification supports a flexible and distributed). The HMIPv6 specification supports a flexible
selection of the MAP (e.g., based on the distance between the MN and selection of the MAP (e.g., based on the distance between the MN and
the MAP, taking into consideration the expected mobility pattern of the MAP, taking into consideration the expected mobility pattern of
the MN, etc.). the MN, etc.).
An additional extension that can be used to help deploying a mobility Another extension that can be used to help distributing mobility
protocol in a distributed mobility management environment is the Home management functions is the Home Agent switch specification
Agent switch specification [RFC5142], which defines a new mobility [RFC5142], which defines a new mobility header for signaling a mobile
header for signaling a mobile node that it should acquire a new home node that it should acquire a new home agent. [RFC5142] does not
agent. Even though the purposes of this specification do not include specify the case of changing the mobile node's home address, as that
the case of changing the mobile node's home address, as that might might imply loss of connectivity for ongoing persistent connections.
imply loss of connectivity for ongoing persistent connections, it Nevertheless, that specification could be used to force the change of
could be used to force the change of home agent in those situations home agent in those situations where there are no active persistent
where there are no active persistent data sessions that cannot cope data sessions that cannot cope with a change of home address.
with a change of home address.
There are other host-based approaches standardized within IETF that There are other host-based approaches standardized within IETF that
can be used to provide mobility support. For example MOBIKE can be used to provide mobility support. For example MOBIKE
[RFC4555] allows a mobile node encrypting traffic through IKEv2 [RFC4555] allows a mobile node encrypting traffic through IKEv2
[RFC5996] to change its point of attachment while maintaining a [RFC5996] to change its point of attachment while maintaining a
Virtual Private Network (VPN) session. The MOBIKE protocol allows Virtual Private Network (VPN) session. The MOBIKE protocol allows
updating the VPN Security Associations (SAs) in cases where the base updating the VPN Security Associations (SAs) in cases where the base
connection initially used is lost and needs to be re-established. connection initially used is lost and needs to be re-established.
The use of the MOBIKE protocol avoids having to perform an IKEv2 re- The use of the MOBIKE protocol avoids having to perform an IKEv2 re-
negotiation. Similar considerations to those made for Mobile IPv6 negotiation. Similar considerations to those made for Mobile IPv6
can be applied to MOBIKE; though MOBIKE is best suited for situations can be applied to MOBIKE; though MOBIKE is best suited for situations
where the address of at least one endpoint is relatively stable and where the address of at least one endpoint is relatively stable and
can be discovered using existing mechanisms such as DNS. can be discovered using existing mechanisms such as DNS.
IETF has defined extensions to the mobility protocol to optimize the
handover performance. Mobile IPv6 Fast Handovers(FMIP) [RFC5568] is
the extension to optimize handover latency. It defines new access
router discovery mechanism before handover to reduce the new network
discovery latency. It also defines a tunnel between the previous
access router and the new access router to reduce the packet loss
during handover. IETF seamoby working group alos has published
Candidate Access Router Discovery(CARD) [RFC4066] and Context
Transfer Protocol (CXTP) [RFC4067] to improve the handover
performance. The DMM deployment pratice discussed in this section
can also use thoes extensions to improve the handover performance.
4.2.2. Network-based IP DMM practices 4.2.2. Network-based IP DMM practices
Proxy Mobile IPv6 (PMIPv6) [RFC5213] is the main network-based IP Proxy Mobile IPv6 (PMIPv6) [RFC5213] is the main network-based IP
mobility protocol specified for IPv6 ([RFC5844] defines some IPv4 mobility protocol specified for IPv6. Proxy Mobile IPv4 [RFC5844]
extensions). With network-based IP mobility protocols, the local defines some IPv4 extensions. With network-based IP mobility
mobility anchor (LMA) typically provides the anchoring function (AF), protocols, the local mobility anchor (LMA) typically provides the
Routing management (RM) function, Internetwork Location Management anchoring function (AF), Forwarding management (FM) function,
server (LMs) function and RM function. The mobile access gateway internetwork Location Management server (LMs) function and RM
(MAG) provides the Location Management client (LMc) function and function. The mobile access gateway (MAG) provides the Location
Routing management (RM) function to tunnel with LMA. PMIPv6 is Management client (LMc) function and Forwarding management (FM)
architecturally similar to MIPv6, as the mobility signaling and function to tunnel with LMA. PMIPv6 is architecturally almost
routing between LMA and MAG in PMIPv6 is similar to those between HA identical to MIPv6, as the mobility signaling and routing between LMA
and MN in MIPv6. The required mobility functionality at the MN is and MAG in PMIPv6 is similar to those between HA and MN in MIPv6.
provided by the MAG so that the involvement in mobility support by The required mobility functionality at the MN is provided by the MAG
the MN is not required. so that the involvement in mobility support by the MN is not
required.
We next describe some practices on how network-based mobility We next describe some practices that show how network-based mobility
protocols and several additional protocol extensions can be deployed protocols and several other protocol extensions can be deployed in a
in a distributed mobility management environment. distributed mobility management environment.
One simple but still suboptimal approach to decentralize Proxy Mobile One way to decentralize Proxy Mobile IPv6 operation can be to deploy
IPv6 operation can be to deploy several local mobility anchors and several local mobility anchors and use some selection criteria to
use some selection criteria to assign LMAs to attaching mobile nodes assign LMAs to attaching mobile nodes (an example of this type of
(an example of this type of assignment is shown in Figure 4). As per assignment is shown in Figure 4). As with the client based approach,
the client based approach, a mobile node may use several anchors at a mobile node may use several anchors at the same time, each of them
the same time, each of them anchoring IP flows initiated at a anchoring IP flows initiated at a different point of attachment.
different point of attachment. This assignment can be static or This assignment can be static or dynamic. The main advantage of this
dynamic (as described later in this document). The main advantage of simple approach is that the IP address anchor (i.e., the LMA) could
this simple approach is that the IP address anchor (i.e., the LMA) be placed closer to the mobile node. Therefore the resulting paths
could be placed closer to the mobile node. Therefore the resulting are close-to-optimal. On the other hand, as soon as the mobile node
paths are close-to-optimal. On the other hand, as soon as the mobile moves, the resulting path will start deviating from the optimal one.
node moves, the resulting path will start deviating from the optimal
one.
<- INTERNET -><- HOME NET -><----------- ACCESS NETWORK ------------> <- INTERNET -><- HOME NET -><----------- ACCESS NETWORK ------------>
------- -------
| CN1 | -------- -------- -------- | CN1 | -------- -------- --------
------- -------- | MAG1 | | MAG2 | | MAG3 | ------- -------- | MAG1 | | MAG2 | | MAG3 |
| LMA1 | ---+---- ---+---- ---+---- | LMA1 | ---+---- ---+---- ---+----
------- -------- | | | ------- -------- | | |
| CN2 | (o) (o) (o) | CN2 | (o) (o) (o)
------- -------- x x ------- -------- x x
| LMA2 | x x | LMA2 | x x
skipping to change at page 13, line 22 skipping to change at page 14, line 16
mobile node does not have any active session, or when the running mobile node does not have any active session, or when the running
sessions can survive an IP address change. Note that several sessions can survive an IP address change. Note that several
possible dynamic local mobility anchor discovery solutions can be possible dynamic local mobility anchor discovery solutions can be
used, as described in [RFC6097]. used, as described in [RFC6097].
4.3. 3GPP network flattening approaches 4.3. 3GPP network flattening approaches
The 3rd Generation Partnership Project (3GPP) is the standards The 3rd Generation Partnership Project (3GPP) is the standards
development organization that specifies the 3rd generation mobile development organization that specifies the 3rd generation mobile
network and the Evolved Packet System (EPS), which mainly comprises network and the Evolved Packet System (EPS), which mainly comprises
the Evolved Packet Core (EPC) and a new radio access network, the Evolved Packet Core (EPC) and a new radio access network, usually
sometimes referred to as LTE (Long Term Evolution). referred to as LTE (Long Term Evolution).
Architecturally, the 3GPP Evolved Packet Core (EPC) network is Architecturally, the 3GPP Evolved Packet Core (EPC) network is
similar to an IP wireless network running PMIPv6 or MIPv6, as it similar to an IP wireless network running PMIPv6 or MIPv6, as it
relies on the Packet Data Gateway (PGW) anchoring services to provide relies on the Packet Data Gateway (PGW) anchoring services to provide
mobile nodes with mobility support (see Figure 5). There are client- mobile nodes with mobility support (see Figure 5). There are client-
based and network-based mobility solutions in 3GPP, which for based and network-based mobility solutions in 3GPP, which for
simplicity will be analyzed together. We next describe how 3GPP simplicity will be analyzed together. We next describe how 3GPP
mobility protocols and several additional completed or ongoing mobility protocols and several other completed or ongoing extensions
extensions can be deployed to meet some of the DMM requirements can be deployed to meet some of the DMM requirements
[I-D.ietf-dmm-requirements]. [I-D.ietf-dmm-requirements].
+---------------------------------------------------------+ +---------------------------------------------------------+
| PCRF | | PCRF |
+-----------+--------------------------+----------------+-+ +-----------+--------------------------+----------------+-+
| | | | | |
+----+ +-----------+------------+ +--------+-----------+ +-+-+ +----+ +-----------+------------+ +--------+-----------+ +-+-+
| | | +-+ | | Core Network | | | | | | +-+ | | Core Network | | |
| | | +------+ |S|__ | | +--------+ +---+ | | | | | | +------+ |S|__ | | +--------+ +---+ | | |
| | | |GERAN/|_|G| \ | | | HSS | | | | | | | | | |GERAN/|_|G| \ | | | HSS | | | | | |
skipping to change at page 14, line 35 skipping to change at page 16, line 4
protocol specified for 3GPP networks (S2a, S2b, S5 and S8 protocol specified for 3GPP networks (S2a, S2b, S5 and S8
interfaces). Similar to PMIPv6, it can handle mobility without interfaces). Similar to PMIPv6, it can handle mobility without
requiring the involvement of the mobile nodes. In this case, the requiring the involvement of the mobile nodes. In this case, the
mobile node functionality is provided in a proxy manner by the mobile node functionality is provided in a proxy manner by the
Serving Data Gateway (SGW), Evolved Packet Data Gateway (ePDG), or Serving Data Gateway (SGW), Evolved Packet Data Gateway (ePDG), or
Trusted Wireless Access Gateway (TWAG). Trusted Wireless Access Gateway (TWAG).
3GPP specifications also include client-based mobility support, based 3GPP specifications also include client-based mobility support, based
on adopting the use of Dual-Stack Mobile IPv6 (DSMIPv6) [RFC5555] for on adopting the use of Dual-Stack Mobile IPv6 (DSMIPv6) [RFC5555] for
the S2c interface. In this case, the User Equipment (UE) implements the S2c interface. In this case, the User Equipment (UE) implements
the mobile node functionality, while the home agent role is played by the binding update functionality, while the home agent role is played
the PGW. by the PGW.
A Local IP Access (LIPA) and Selected IP Traffic Offload (SIPTO) A Local IP Access (LIPA) and Selected IP Traffic Offload (SIPTO)
enabled network [SDO-3GPP.23.401] allows offloading some IP services enabled network [SDO-3GPP.23.401] allows offloading some IP services
at the local access network, above the Radio Access Network (RAN) or at the local access network, above the Radio Access Network (RAN) or
at the macro, without the need to traverse back to the PGW (see at the macro, without the need to travel back to the PGW (see
Figure 6). Figure 6).
+---------+ IP traffic to mobile operator's CN +---------+ IP traffic to mobile operator's CN
| User |....................................(Operator's CN) | User |....................................(Operator's CN)
| Equipm. |.................. | Equipm. |..................
+---------+ . Local IP traffic +---------+ . Local IP traffic
. .
+-----------+ +-----------+
|Residential| |Residential|
|enterprise | |enterprise |
|IP network | |IP network |
+-----------+ +-----------+
Figure 6: LIPA scenario Figure 6: LIPA scenario
SIPTO enables an operator to offload certain types of traffic at a SIPTO enables an operator to offload certain types of traffic at a
network node close to the UE's point of attachment to the access network node close to the UE's point of attachment to the access
network, by selecting a set of GWs (SGW and PGW) that are network, by selecting a set of GWs (SGW and PGW) that are
geographically/topologically close to the UE's point of attachment. geographically/topologically close to the UE's point of attachment.
SIPTO Traffic SIPTO Traffic
| |
skipping to change at page 15, line 28 skipping to change at page 16, line 45
+------+ +------+ +------+ +------+
|L-PGW | ---- | MME | |L-PGW | ---- | MME |
+------+ / +------+ +------+ / +------+
| / | /
+-------+ +------+ +------+/ +------+ +-------+ +------+ +------+/ +------+
| UE |.....|eNB |....| S-GW |........| P-GW |...> CN Traffic | UE |.....|eNB |....| S-GW |........| P-GW |...> CN Traffic
+-------+ +------+ +------+ +------+ +-------+ +------+ +------+ +------+
Figure 7: SIPTO architecture Figure 7: SIPTO architecture
LIPA, on the other hand, enables an IP capable UE connected via a LIPA, on the other hand, enables an IP addressable UE connected via a
Home eNB (HeNB) to access other IP capable entities in the same Home eNB (HeNB) to access other IP addressable entities in the same
residential/enterprise IP network without traversing the mobile residential/enterprise IP network without traversing the mobile
operator's network core in the user plane. In order to achieve this, operator's network core in the user plane. In order to achieve this,
a Local GW (L-GW) collocated with the HeNB is used. LIPA is a Local GW (L-GW) collocated with the HeNB is used. LIPA is
established by the UE requesting a new PDN connection to an access established by the UE requesting a new PDN (Public Data Network)
point name for which LIPA is permitted, and the network selecting the connection to an access point name for which LIPA is permitted, and
Local GW associated with the HeNB and enabling a direct user plane the network selecting the Local GW associated with the HeNB and
path between the Local GW and the HeNB. enabling a direct user plane path between the Local GW and the HeNB.
+---------------+-------+ +----------+ +-------------+ ===== +---------------+-------+ +----------+ +-------------+ =====
|Residential | |H(e)NB | | Backhaul | |Mobile | ( IP ) |Residential | |H(e)NB | | Backhaul | |Mobile | ( IP )
|Enterprise |..|-------|..| |..|Operator |..(Network) |Enterprise |..|-------|..| |..|Operator |..(Network)
|Network | |L-GW | | | |Core network | ======= |Network | |L-GW | | | |Core network | =======
+---------------+-------+ +----------+ +-------------+ +---------------+-------+ +----------+ +-------------+
/ /
| |
/ /
+-----+ +-----+
| UE | | UE |
+-----+ +-----+
Figure 8: LIPA architecture Figure 8: LIPA architecture
The 3GPP architecture specifications also provide mechanisms to allow The 3GPP architecture specifications also provide mechanisms to allow
discovery and selection of gateways [SDO-3GPP.29.303]. These discovery and selection of gateways [SDO-3GPP.29.303]. These
mechanisms enable decisions taking into consideration topological mechanisms enable decisions taking into consideration topological
location and gateway collocation aspects, using heavily the DNS as a location and gateway collocation aspects, relying upon the DNS as a
"location database". "location database".
Both SIPTO and LIPA have a very limited mobility support, specially Both SIPTO and LIPA have a very limited mobility support, specially
in 3GPP specifications up to Rel-12. In a glimpse, LIPA mobility in 3GPP specifications up to Rel-12. Briefly, LIPA mobility support
support is limited to handovers between HeNBs that are managed by the is limited to handovers between HeNBs that are managed by the same
same L-GW (i.e., mobility within the local domain), while seamless L-GW (i.e., mobility within the local domain), while seamless
SIPTO mobility is still limited to the case where the SGW/PGW is at mobility is not supported when SIPTO is performed at or near the RAN
or above Radio Access Network (RAN) level. level.
5. Gap analysis 5. Gap analysis
The goal of this section is to identify the limitations in the The goal of this section is to identify the limitations in the
current practices, described in Section 4, with respect to the DMM current practices, described in Section 4, with respect to the DMM
requirements listed in [I-D.ietf-dmm-requirements]. requirements listed in [I-D.ietf-dmm-requirements].
5.1. Distributed processing - REQ1 5.1. Distributed processing - REQ1
According to requirement #1 stated in [I-D.ietf-dmm-requirements], IP According to requirement #1 stated in [I-D.ietf-dmm-requirements], IP
mobility, network access and routing solutions provided by DMM MUST mobility, network access and routing solutions provided by DMM must
enable distributed processing for mobility management so that traffic enable distributed processing for mobility management so that traffic
can avoid traversing single mobility anchor far from the optimal can avoid traversing single mobility anchor far from the optimal
route. route.
From the analysis performed in Section 4, a DMM deployment can meet From the analysis performed in Section 4, a DMM deployment can meet
the requirement "REQ#1 Distributed processing" usually relying on the the requirement "REQ#1 Distributed processing" usually relying on the
following functions: following functions:
o Multiple (distributed) anchoring: ability to anchor different o Multiple (distributed) anchoring: ability to anchor different
sessions of a single mobile node at different anchors. In order sessions of a single mobile node at different anchors. In order
to make this feature "DMM-friendly", some anchors might need to be to provide improved routing, some anchors might need to be placed
placed closer to the mobile node. closer to the mobile node.
o Dynamic anchor assignment/re-location: ability to i) optimally o Dynamic anchor assignment/re-location: ability to i) assign the
assign initial anchor, and ii) dynamically change the initially initial anchor, and ii) dynamically change the initially assigned
assigned anchor and/or assign a new one (this may also require to anchor and/or assign a new one (this may also require to transfer
transfer mobility context between anchors). This can be achieved mobility context between anchors). This can be achieved either by
either by changing anchor for all ongoing sessions, or by changing anchor for all ongoing sessions, or by assigning new
assigning new anchors just for new sessions. anchors just for new sessions.
Both the main client- and network-based IP mobility protocols, namely Both the main client- and network-based IP mobility protocols, namely
(DS)MIPv6 and PMIPv6 allow deploying multiple anchors (i.e., home (DS)MIPv6 and PMIPv6 allow deploying multiple anchors (i.e., home
agents and localized mobility anchors), therefore providing the agents and localized mobility anchors), therefore providing the
multiple anchoring function. However, existing solutions only multiple anchoring function. However, existing solutions only
provide an optimal initial anchor assignment, thus the lack of provide an initial anchor assignment, thus the lack of dynamic anchor
dynamic anchor change/new anchor assignment is a gap. Neither the HA change/new anchor assignment is a gap. Neither the HA switch nor the
switch nor the LMA runtime assignment allow changing the anchor LMA runtime assignment allow changing the anchor during an ongoing
during an ongoing session. This actually comprises several gaps: session. This actually comprises several gaps: ability to perform
ability to perform anchor assignment at any time (not only at the anchor assignment at any time (not only at the initial MN's
initial MN's attachment), ability of the current anchor to initiate/ attachment), ability of the current anchor to initiate/trigger the
trigger the relocation, and ability to transfer registration context relocation, and ability to transfer registration context between
between anchors. anchors.
Dynamic anchor assignment may lead the MN to manage different Dynamic anchor assignment may lead the MN to manage different
mobility sessions served by different mobility anchors. This is not mobility sessions served by different mobility anchors. This is not
an issue with client based mobility management where the mobility an issue with client based mobility management where the mobility
client natively knows each anchor associated to each mobility client natively knows each anchor associated to each mobility
sessions. However, there is one gap, as the MN should be capable of sessions. However, there is one gap, as the MN should be capable of
handling IP addresses in a DMM-friendly way, meaning that the MN can handling IP addresses in a DMM-friendly way, meaning that the MN can
perform smart source address selection (i.e., deprecating IP perform smart source address selection (i.e., deprecating IP
addresses from previous mobility anchors, so they are not used for addresses from previous mobility anchors, so they are not used for
new sessions). Besides, managing different mobility sessions served new sessions). Besides, managing different mobility sessions served
skipping to change at page 18, line 4 skipping to change at page 19, line 21
on the link) or the MAP option in Router Advertisements defined by on the link) or the MAP option in Router Advertisements defined by
HMIPv6. Note that there are 3GPP mechanisms providing that HMIPv6. Note that there are 3GPP mechanisms providing that
functionality defined in [SDO-3GPP.29.303]. functionality defined in [SDO-3GPP.29.303].
Also note that REQ1 is such that the data plane traffic can avoid Also note that REQ1 is such that the data plane traffic can avoid
suboptimal route. Distributed processing of the traffic is then suboptimal route. Distributed processing of the traffic is then
needed only in the data plane. The needed capability in distributed needed only in the data plane. The needed capability in distributed
processing therefore should not contradict with centralized control processing therefore should not contradict with centralized control
plane. Other control plane solutions such as charging, lawful plane. Other control plane solutions such as charging, lawful
interception, etc. should not be limited. Yet combining the control interception, etc. should not be limited. Yet combining the control
plane and data plane routing management (RM) function may limit the plane and data plane forwarding management (FM) function may limit
choice to distributing boht data plane and control plane together. the choice to distributing boht data plane and control plane
In order to enable distributing only the data plane without together. In order to enable distributing only the data plane
distributing the control plane, a gap is to split the routing without distributing the control plane, a gap is to split the
management function into the control plane (RM-CP) and data plane forwarding management function into the control plane (FM-CP) and
(RM-DP). data plane (FM-DP).
5.2. Bypassable network-layer mobility support - REQ2 5.2. On-demand network-layer mobility support - REQ2
The need for "bypassable network-layer mobility support" introduced The need for "on-demand network-layer mobility support" introduced in
in [I-D.ietf-dmm-requirements] will enable dynamic mobility [I-D.ietf-dmm-requirements] will enable dynamic mobility management.
management. Note that this requirement is not on dynamic mobilitly management. Flexibility on the determination of whether network-
itself but only enables it. It therefore leaves flexibility on the layer mobility support is needed. The requirement enables one to
determination of whether network-layer mobility support is needed and choose whether or not use network-layer mobility support. It only
the role to use of not use network-layer mobility support. The enables the two following functions:
requirement only enables one to use or not use network-layer mobility
support. It only enables the which basically leverages the two
following functions:
o Dynamically assign/relocate anchor: a mobility anchor is assigned o Dynamically assign/relocate anchor: a mobility anchor is assigned
only to sessions which uses the network-layer mobility support. only to sessions which uses the network-layer mobility support.
The MN may thus manage more than one session; some of them may be The MN may thus manage more than one session; some of them may be
associated with anchored IP address(es), while the others may be associated with anchored IP address(es), while the others may be
associated with local IP address(es). associated with local IP address(es).
o Multiple IP address management: this function is related to the o Multiple IP address management: this function is related to the
preceding and is about the ability of the mobile node to preceding and is about the ability of the mobile node to
simultaneously use multiple IP addresses and select the best one simultaneously use multiple IP addresses and select the best one
(from an anchoring point of view) to use on a per-session/ (from an anchoring point of view) to use on a per-session/
application/service basis. application/service basis. This requires MN to acquire
information regarding the properties of the available IP
addresses.
The dynamic anchor assignment/relocation needs to ensure that IP The dynamic anchor assignment/relocation needs to ensure that IP
address continuity is guaranteed for sessions that uses such mobility address continuity is guaranteed for sessions that uses such mobility
support (e.g., in some scenarios, the provision of mobility locally support (e.g., in some scenarios, the provision of mobility locally
within a limited area might be enough from the mobile node or the within a limited area might be enough from the mobile node or the
application point of view) at the relocated anchor. Implicitly, when application point of view) at the relocated anchor. Implicitly, when
no applications are using the network-layer mobility support, DMM may no applications are using the network-layer mobility support, DMM may
releave the needed resources. This may imply having the knowledge of release the needed resources. This may imply having the knowledge of
which sessions at the mobile node are active and are using the which sessions at the mobile node are active and are using the
mobility support. This is something typically known only by the MN mobility support. This is something typically known only by the MN
(e.g., by its connection manager). Therefore, (part of) this (e.g., by its connection manager). Therefore, (part of) this
knowledge might need to be transferred to/shared with the network. knowledge might need to be transferred to/shared with the network.
Multiple IP address management provides the MN with the choice to Multiple IP address management provides the MN with the choice to
pick-up the correct address (provided with mobility support or not) pick-up the correct address (provided with mobility support or not)
depending on the application requirements. When using client based depending on the application requirements. When using client based
mobility management, the mobile node is natively aware about the mobility management, the mobile node is itself aware of the anchoring
anchoring capabilities of its assigned IP addresses. This is not the capabilities of its assigned IP addresses. This is not necessarily
case with network based IP mobility management and current mechanisms the case with network based IP mobility management; current
does not allow the MN to be aware of the IP addresses properties mechanisms do not allow the MN to be aware of the properties of its
(i.e., the MN does not know whether the allocated IP addresses are IP addresses (e.g., the MN does not know whether the allocated IP
anchored). However, there are ongoing IETF works that are proposing addresses are anchored). However, there are proposals that the
that the network could indicate the different IP addresses properties network could indicate such IP address properties during assignment
during assignment procedures, such as procedures, such as [I-D.bhandari-dhc-class-based-prefix],
[I-D.bhandari-dhc-class-based-prefix],
[I-D.korhonen-6man-prefix-properties] and [I-D.anipko-mif-mpvd-arch]. [I-D.korhonen-6man-prefix-properties] and [I-D.anipko-mif-mpvd-arch].
However, although there exist these individual efforts that could be Although there exist these individual efforts that could be be
be considered as attempts to fix the gap, there is no solution close considered as attempts to fix the gap, there is no solution adopted
to be adopted and standardized in IETF. as a work item within any IETF working group..
The handling of mobility management to the granularity of an
individual session of a user/device SHOULD need proper session
identification in addition to user/device identification.
5.3. IPv6 deployment - REQ3 5.3. IPv6 deployment - REQ3
This requirement states that DMM solutions SHOULD primarily target This requirement states that DMM solutions should primarily target
IPv6 as the primary deployment environment. IPv4 support is not IPv6 as the primary deployment environment. IPv4 support is not
considered mandatory and solutions SHOULD NOT be tailored considered mandatory and solutions should not be tailored
specifically to support IPv4, in particular in situations where specifically to support IPv4.
private IPv4 addresses and/or NATs are used.
All analyzed DMM practices support IPv6. Some of them, such as MIPv6 All analyzed DMM practices support IPv6. Some of them, such as
/NEMO (including the support of dynamic HA selection), MOBIKE, SIPTO MIPv6/NEMO (including the support of dynamic HA selection), MOBIKE,
have also IPv4 support. Additionally, there are also some solutions SIPTO have also IPv4 support. There are also some solutions that
that have some limited IPv4 support (e.g., PMIPv6). In conclusion, have some limited IPv4 support (e.g., PMIPv6). In conclusion, this
this requirement is met by existing DMM practices. requirement is met by existing DMM practices.
5.4. Existing mobility protocols - REQ4 5.4. Existing mobility protocols - REQ4
A DMM solution MUST first consider reusing and extending IETF- A DMM solution must first consider reusing and extending IETF-
standardized protocols before specifying new protocols. standardized protocols before specifying new protocols.
As stated in [I-D.ietf-dmm-requirements], a DMM solution could reuse As stated in [I-D.ietf-dmm-requirements], a DMM solution could reuse
existing IETF and standardized protocols before specifying new existing IETF and standardized protocols before specifying new
protocols. Besides, Section 4 of this document discusses various protocols. Besides, Section 4 of this document discusses various
ways to flatten and distribute current mobility solutions. Actually, ways to flatten and distribute current mobility solutions. Actually,
nothing prevent the distribution of mobility functions with vanilla nothing prevent the distribution of mobility functions with in IP
IP mobility protocols. However, as discussed in Section 5.1 and mobility protocols. However, as discussed in Section 5.1 and
Section 5.2, limitations exist. The 3GPP data plane anchoring Section 5.2, limitations exist. The 3GPP data plane anchoring
function, i.e., the PGW, can be also be distributed, but with function, i.e., the PGW, can be also be distributed, but with
limitations; e.g., no anchoring relocation, no context transfer limitations; e.g., no anchoring relocation, no context transfer
between anchors, centralized control plane. The 3GPP architecture is between anchors, centralized control plane. The 3GPP architecture is
also going into the direction of flattening with SIPTO and LIPA, also going into the direction of flattening with SIPTO and LIPA,
though they do not provide mobility support. though they do not provide mobility support.
5.5. Co-existence - REQ5 5.5. Co-existence - REQ5
According to [I-D.ietf-dmm-requirements], DMM solution MUST be able According to [I-D.ietf-dmm-requirements], DMM solution must be able
to co-exist with existing network deployments, end hosts and routers. to co-exist with existing network deployments, end hosts and routers.
All current mobility protocols can co-exist with existing network All current mobility protocols can co-exist with existing network
deployments and end hosts. There is no gap between existing mobility deployments and end hosts. There is no gap between existing mobility
protocols and this requirement. protocols and this requirement.
5.6. Security considerations - REQ6 5.6. Security considerations - REQ6
As stated in [I-D.ietf-dmm-requirements], a DMM solution MUST NOT NOT As stated in [I-D.ietf-dmm-requirements], a DMM solution must not
introduce new security risks, or amplify existing security risks, introduce new security risks, or amplify existing security risks,
that cannot be mitigated by existing security mechanisms or that cannot be mitigated by existing security mechanisms or
protocols. Current mobility protocols have all security mechanisms protocols. Current mobility protocols have all security mechanisms
in place. For example, Mobile IPv6 defines security features to in place. For example, Mobile IPv6 defines security features to
protect binding updates both to home agents and correspondent nodes. protect binding updates both to home agents and correspondent nodes.
It also defines mechanisms to protect the data packets transmission It also defines mechanisms to protect the data packets transmission
for Mobile IPv6 users. Proxy Mobile IPv6 and other variation of for Mobile IPv6 users. Proxy Mobile IPv6 and other variations of
mobile IP also have similar security considerations. mobile IP also have similar security considerations.
5.7. Multicast - REQ7 5.7. Multicast - REQ7
It is stated in [I-D.ietf-dmm-requirements] that DMM solutions SHOULD It is stated in [I-D.ietf-dmm-requirements] that DMM solutions should
enable multicast solutions to be developed to avoid network enable multicast solutions to be developed to avoid network
inefficiency in multicast traffic delivery. inefficiency in multicast traffic delivery.
Current IP mobility solutions address mainly the mobility problem for Current IP mobility solutions address mainly the mobility problem for
unicast traffic. Solutions relying on the use of an anchor point for unicast traffic. Solutions relying on the use of an anchor point for
tunneling multicast traffic down to the access router, or to the tunneling multicast traffic down to the access router, or to the
mobile node, introduce the so-called "tunnel convergence problem". mobile node, introduce the so-called "tunnel convergence problem".
This means that multiple instances of the same multicast traffic can This means that multiple instances of the same multicast traffic can
converge to the same node, defeating hence the advantage of using converge to the same node, diminishing the advantage of using
multicast protocols. multicast protocols.
The MULTIMOB WG in IETF has studied this issue, for the specific case The MULTIMOB WG in IETF has studied this issue, for the specific case
of PMIPv6, and has produced a baseline solution [RFC6224] as well as of PMIPv6, and has produced a baseline solution [RFC6224] as well as
a routing optimization solution [RFC7028] to address the problem. a routing optimization solution [RFC7028] to address the problem.
The baseline solution suggests deploying an MLD proxy function at the The baseline solution suggests deploying an MLD proxy function at the
MAG, and either a multicast router or another MLD proxy function at MAG, and either a multicast router or another MLD proxy function at
the LMA. The routing optimization solution describes an architecture the LMA. The routing optimization solution describes an architecture
where a dedicated multicast tree mobility anchor (MTMA) or a direct where a dedicated multicast tree mobility anchor (MTMA) or a direct
routing option can be used to avoid the tunnel convergence problem. routing option can be used to avoid the tunnel convergence problem.
Besides the solutions proposed in MULTIMOB for PMIPv6, there are no Besides the solutions proposed in MULTIMOB for PMIPv6 within the
solutions for other mobility protocols to address the multicast IETF, there are no other solutions for other mobility protocols to
tunnel convergence problem. address the multicast tunnel convergence problem.
5.8. Summary 5.8. Summary
We next list the main gaps identified from the analysis performed We next list the main gaps identified from the analysis performed
above: above:
o Existing solutions do only provide an optimal initial anchor o Existing solutions only provide an optimal initial anchor
assignment, a gap being the lack of dynamic anchor change/new assignment, a gap being the lack of dynamic anchor change/new
anchor assignment. Neither the HA switch nor the LMA runtime anchor assignment. Neither the HA switch nor the LMA runtime
assignment allow changing the anchor during an ongoing session. assignment allow changing the anchor during an ongoing session.
While MOBIKE could be used to switch from a gateway to another in While MOBIKE could be used to switch from a gateway to another in
the middle of a session from MN side, there is no protocol support the middle of a session from MN side, there is no protocol support
for the network side. for the network side.
o The mobile node needs to simultaneously use multiple IP addresses, o The mobile node needs to simultaneously use multiple IP addresses
which requires additional support which might not be available on with different properties, which requires to expose this
the mobile node's stack, especially for the case of network-based information to the mobile node and to update accordingly the
solutions. source address selection mechanism of the latter.
o Currently, there is no efficient mechanism specified by the IETF o Currently, there is no efficient mechanism specified by the IETF
that allows to dynamically discover the presence of nodes that can that allows to dynamically discover the presence of nodes that can
play the role of anchor, discover their capabilities and allow the play the role of anchor, discover their capabilities and allow the
selection of the most suitable one. There are though some selection of the most suitable one. However, the following
mechanisms that could help discovering anchors, such as the mechanisms that could help discovering anchors:
Dynamic Home Agent Address Discovery (DHAAD), the use of the Home
o Dynamic Home Agent Address Discovery (DHAAD) the use of the Home
Agent (H) flag in Router Advertisements (which indicates that the Agent (H) flag in Router Advertisements (which indicates that the
router sending the Router Advertisement is also functioning as a router sending the Router Advertisement is also functioning as a
Mobile IPv6 home agent on the link) or the MAP option in Router Mobile IPv6 home agent on the link) and
Advertisements defined by HMIPv6.
o While existing network-based DMM practices may allow to deploy o the MAP option in Router Advertisements defined by HMIPv6.
multiple LMAs and dynamically select the best one, this requires
to still keep some centralization in the control plane, to access o While existing network-based DMM practices may allow deployment
on the policy store (as defined in RFC5213). Currently, there is multiple LMAs and dynamic selection of the best one, doing so
a lack of solutions/extensions that support a clear control and requires some centralization in the control plane, for access the
data plane separation for IETF IP mobility protocols. policy database (as defined in RFC5213). Although
[I-D.ietf-netext-pmip-cp-up-separation] allows a MAG to perform
splitting of its control and user planes, there is a lack of
solutions/extensions that support a clear control and data plane
separation for IETF IP mobility protocols in a DMM context.
6. Security Considerations 6. Security Considerations
This document does not define any protocol, so it does not introduce Distributed mobility management systems encounter same security
any new security concern. threats as existing centralized IP mobility protocols. Without
authentication, a malicious node could forge signaling messages and
redirect traffic from its legitimate path. This would amount to a
denial of service attack against the specific node or nodes for which
the traffic is intended. Distributed mobility anchoring, while
keeping current security mechanisms, might require more security
associations to be managed by the mobility management entities,
potentially leading to scalability and performance issues. Moreover,
distributed mobility anchoring makes mobility security problems more
complex, since traffic redirection requests might come from
previously unconsidered origins, thus leading to distributed points
of attack. Consequently, the DMM security design must account for
the distribution of security associations between additional mobility
entities.
7. IANA Considerations 7. IANA Considerations
None. None.
8. References 8. Contributors
8.1. Normative References
The following people have made significant contribution for this
document.
Charles E. Perkins
Huawei Technologies
Email: charliep@computer.org
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
8.2. Informative References 9.2. Informative References
[I-D.anipko-mif-mpvd-arch] [I-D.anipko-mif-mpvd-arch]
Anipko, D., "Multiple Provisioning Domain Architecture", Anipko, D., "Multiple Provisioning Domain Architecture",
draft-anipko-mif-mpvd-arch-05 (work in progress), November draft-anipko-mif-mpvd-arch-05 (work in progress), November
2013. 2013.
[I-D.bhandari-dhc-class-based-prefix] [I-D.bhandari-dhc-class-based-prefix]
Systems, C., Halwasia, G., Gundavelli, S., Deng, H., Systems, C., Halwasia, G., Gundavelli, S., Deng, H.,
Thiebaut, L., Korhonen, J., and I. Farrer, "DHCPv6 class Thiebaut, L., Korhonen, J., and I. Farrer, "DHCPv6 class
based prefix", draft-bhandari-dhc-class-based-prefix-05 based prefix", draft-bhandari-dhc-class-based-prefix-05
skipping to change at page 22, line 31 skipping to change at page 24, line 27
[I-D.gundavelli-v6ops-community-wifi-svcs] [I-D.gundavelli-v6ops-community-wifi-svcs]
Gundavelli, S., Grayson, M., Seite, P., and Y. Lee, Gundavelli, S., Grayson, M., Seite, P., and Y. Lee,
"Service Provider Wi-Fi Services Over Residential "Service Provider Wi-Fi Services Over Residential
Architectures", draft-gundavelli-v6ops-community-wifi- Architectures", draft-gundavelli-v6ops-community-wifi-
svcs-06 (work in progress), April 2013. svcs-06 (work in progress), April 2013.
[I-D.ietf-dmm-requirements] [I-D.ietf-dmm-requirements]
Chan, A., Liu, D., Seite, P., Yokota, H., and J. Korhonen, Chan, A., Liu, D., Seite, P., Yokota, H., and J. Korhonen,
"Requirements for Distributed Mobility Management", draft- "Requirements for Distributed Mobility Management", draft-
ietf-dmm-requirements-12 (work in progress), December ietf-dmm-requirements-16 (work in progress), April 2014.
2013.
[I-D.ietf-netext-pmip-cp-up-separation]
Wakikawa, R., Pazhyannur, R., Gundavelli, S., and C.
Perkins, "Separation of Control and User Plane for Proxy
Mobile IPv6", draft-ietf-netext-pmip-cp-up-separation-03
(work in progress), April 2014.
[I-D.korhonen-6man-prefix-properties] [I-D.korhonen-6man-prefix-properties]
Korhonen, J., Patil, B., Gundavelli, S., Seite, P., and D. Korhonen, J., Patil, B., Gundavelli, S., Seite, P., and D.
Liu, "IPv6 Prefix Properties", draft-korhonen-6man-prefix- Liu, "IPv6 Prefix Properties", draft-korhonen-6man-prefix-
properties-02 (work in progress), July 2013. properties-02 (work in progress), July 2013.
[IEEE.802-16.2009] [IEEE.802-16.2009]
, "IEEE Standard for Local and metropolitan area networks "IEEE Standard for Local and metropolitan area networks
Part 16: Air Interface for Broadband Wireless Access Part 16: Air Interface for Broadband Wireless Access
Systems", IEEE Standard 802.16, 2009, <http:// Systems", IEEE Standard 802.16, 2009,
standards.ieee.org/getieee802/download/802.16-2009.pdf>. <http://standards.ieee.org/getieee802/
download/802.16-2009.pdf>.
[RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. [RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P.
Thubert, "Network Mobility (NEMO) Basic Support Protocol", Thubert, "Network Mobility (NEMO) Basic Support Protocol",
RFC 3963, January 2005. RFC 3963, January 2005.
[RFC4066] Liebsch, M., Singh, A., Chaskar, H., Funato, D., and E.
Shim, "Candidate Access Router Discovery (CARD)", RFC
4066, July 2005.
[RFC4067] Loughney, J., Nakhjiri, M., Perkins, C., and R. Koodli,
"Context Transfer Protocol (CXTP)", RFC 4067, July 2005.
[RFC4225] Nikander, P., Arkko, J., Aura, T., Montenegro, G., and E. [RFC4225] Nikander, P., Arkko, J., Aura, T., Montenegro, G., and E.
Nordmark, "Mobile IP Version 6 Route Optimization Security Nordmark, "Mobile IP Version 6 Route Optimization Security
Design Background", RFC 4225, December 2005. Design Background", RFC 4225, December 2005.
[RFC4555] Eronen, P., "IKEv2 Mobility and Multihoming Protocol [RFC4555] Eronen, P., "IKEv2 Mobility and Multihoming Protocol
(MOBIKE)", RFC 4555, June 2006. (MOBIKE)", RFC 4555, June 2006.
[RFC4640] Patel, A. and G. Giaretta, "Problem Statement for [RFC4640] Patel, A. and G. Giaretta, "Problem Statement for
bootstrapping Mobile IPv6 (MIPv6)", RFC 4640, September bootstrapping Mobile IPv6 (MIPv6)", RFC 4640, September
2006. 2006.
skipping to change at page 23, line 37 skipping to change at page 25, line 48
[RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., [RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008. and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.
[RFC5380] Soliman, H., Castelluccia, C., ElMalki, K., and L. [RFC5380] Soliman, H., Castelluccia, C., ElMalki, K., and L.
Bellier, "Hierarchical Mobile IPv6 (HMIPv6) Mobility Bellier, "Hierarchical Mobile IPv6 (HMIPv6) Mobility
Management", RFC 5380, October 2008. Management", RFC 5380, October 2008.
[RFC5555] Soliman, H., "Mobile IPv6 Support for Dual Stack Hosts and [RFC5555] Soliman, H., "Mobile IPv6 Support for Dual Stack Hosts and
Routers", RFC 5555, June 2009. Routers", RFC 5555, June 2009.
[RFC5568] Koodli, R., "Mobile IPv6 Fast Handovers", RFC 5568, July
2009.
[RFC5844] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy [RFC5844] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
Mobile IPv6", RFC 5844, May 2010. Mobile IPv6", RFC 5844, May 2010.
[RFC5996] Kaufman, C., Hoffman, P., Nir, Y., and P. Eronen, [RFC5996] Kaufman, C., Hoffman, P., Nir, Y., and P. Eronen,
"Internet Key Exchange Protocol Version 2 (IKEv2)", RFC "Internet Key Exchange Protocol Version 2 (IKEv2)", RFC
5996, September 2010. 5996, September 2010.
[RFC6097] Korhonen, J. and V. Devarapalli, "Local Mobility Anchor [RFC6097] Korhonen, J. and V. Devarapalli, "Local Mobility Anchor
(LMA) Discovery for Proxy Mobile IPv6", RFC 6097, February (LMA) Discovery for Proxy Mobile IPv6", RFC 6097, February
2011. 2011.
skipping to change at page 24, line 29 skipping to change at page 26, line 41
[RFC7028] Zuniga, JC., Contreras, LM., Bernardos, CJ., Jeon, S., and [RFC7028] Zuniga, JC., Contreras, LM., Bernardos, CJ., Jeon, S., and
Y. Kim, "Multicast Mobility Routing Optimizations for Y. Kim, "Multicast Mobility Routing Optimizations for
Proxy Mobile IPv6", RFC 7028, September 2013. Proxy Mobile IPv6", RFC 7028, September 2013.
[SDO-3GPP.23.401] [SDO-3GPP.23.401]
3GPP, "General Packet Radio Service (GPRS) enhancements 3GPP, "General Packet Radio Service (GPRS) enhancements
for Evolved Universal Terrestrial Radio Access Network for Evolved Universal Terrestrial Radio Access Network
(E-UTRAN) access", 3GPP TS 23.401 10.10.0, March 2013. (E-UTRAN) access", 3GPP TS 23.401 10.10.0, March 2013.
[SDO-3GPP.23.402]
3GPP, "Architecture enhancements for non-3GPP accesses",
3GPP TS 23.402 10.8.0, September 2012.
[SDO-3GPP.23.859] [SDO-3GPP.23.859]
3GPP, "Local IP access (LIPA) mobility and Selected IP 3GPP, "Local IP access (LIPA) mobility and Selected IP
Traffic Offload (SIPTO) at the local network", 3GPP TR Traffic Offload (SIPTO) at the local network", 3GPP TR
23.859 12.0.1, April 2013. 23.859 12.0.1, April 2013.
[SDO-3GPP.29.060] [SDO-3GPP.29.060]
3GPP, "General Packet Radio Service (GPRS); GPRS 3GPP, "General Packet Radio Service (GPRS); GPRS
Tunnelling Protocol (GTP) across the Gn and Gp interface", Tunnelling Protocol (GTP) across the Gn and Gp interface",
3GPP TS 29.060 3.19.0, March 2004. 3GPP TS 29.060 3.19.0, March 2004.
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