NEMO Working Group C. Ng
Internet-Draft Panasonic Singapore Labs
Expires: November 24, 2003 J. Charbon
Keio and Louis Pasteur University
May 26, 2003
Multi-Homing Issues in Bi-directional Tunneling
draft-ng-nemo-multihoming-issues-01
Status of this Memo
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This Internet-Draft will expire on November 24, 2003.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
This document describes deployment scenario of multi-homed Network in
Motion (NEMO) and attempts to identify issues that arises when
supporting multi-homing in NEMO. It is also the objective of this
document to build a full taxonomy covering multi-homed scenarios in
NEMO, so as to facilitate explorations into this aspect of NEMO.
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Table of Contents
1. Motivations . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Taxonomy . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Explanations of Terms and Illustrations . . . . . . . . . . 5
2.1.1 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . 5
2.1.2 Illustrations . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Classifications of Multi-homed Mobile Network. . . . . . . . 7
2.2.1 (0,0,0): Single MR, Single HA, Single Prefix . . . . . . . . 8
2.2.2 (0,0,1): Single MR, Single HA, Multiple Prefixes . . . . . . 9
2.2.3 (0,1,0): Single MR, Multiple HAs, Single Prefix . . . . . . 9
2.2.4 (0,1,1): Single MR, Multiple HAs, Multiple Prefixes . . . . 10
2.2.5 (1,0,0): Multiple MRs, Single HA, Single Prefix . . . . . . 10
2.2.6 (1,0,1): Multiple MRs, Single HA, Multiple Prefixes . . . . 11
2.2.7 (1,1,0): Multiple MRs, Multiple HAs, Single Prefix . . . . . 11
2.2.8 (1,1,1): Multiple MRs, Multiple HAs, Multiple Prefixes . . . 12
2.3 Alternative Classifications . . . . . . . . . . . . . . . . 13
3. Deployment Scenarios . . . . . . . . . . . . . . . . . . . . 15
4. Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5. Security Considerations . . . . . . . . . . . . . . . . . . 21
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22
References . . . . . . . . . . . . . . . . . . . . . . . . . 23
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 24
Intellectual Property and Copyright Statements . . . . . . . 25
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1. Motivations
The problem of Network Mobility Support (NEMO) is identified in
various previous works [1]. In essence, the problem of network in
motion is to provide continuous Internet connectivity to nodes in a
network that moves as a whole. Nodes within the network that moves
may not be aware of the network changing its point of attachment to
the Internet. This differs from the traditional problem of mobility
support as addressed by Mobile IPv4 [3] and Mobile IPv6 [4].
In Mobile IP, each mobile node has a permanent home domain. When the
mobile node is attached to its home network, it is assigned a
permanent global address known as a home-address (HoA). When the
mobile node is away, i.e. attached to some other foreign networks, it
is usually assigned a temporary global address known as a
care-of-address (CoA). The idea of mobility support is such that the
mobile node can be reached at the home-address even when it is
attached to other foreign networks. This is done in [3][4] with the
introduction of an entity at the home network known as a home agent
(HA). Mobile nodes register their care-of-addresses with the home
agents using messages known as Binding Updates. The home agent is
responsible to intercept messages that are addressed to the mobile
node's home-address, and forward the packet to the mobile node's
care-of-address using IP-in-IP Tunneling [5].
Extending the concept of mobility support for individual hosts to
mobility support for a network of nodes, the objective of a network
in motion solution is to provide a mechanism where nodes in a mobile
network can be reached by their permanent addresses, no matter where
on the Internet the mobile network is attached to. There exist a few
prior attempts to provide network mobility support, most of them
based on using bi-directional tunnels between the mobile routers and
the home agents of the mobile routers [6][7][8][9].
In bi-directional tunnels between mobile routers and home agents, the
mobile router controlling a mobile network performs routing of
packets to and from the mobile network when it is in its home domain.
When the mobile router and its mobile network move to a foreign
domain, the mobile router registers its care-of-address with its home
agent. An IP-in-IP tunnel is then set up between the mobile router
and the home agent. Every packet going to the mobile network will be
intercepted by the home agent and forwarded to the mobile router
through the IP-in-IP tunnel. The mobile router then forwards the
packet to a host in its mobile network. When a node in its mobile
network wishes to send a packet out of the network, the mobile router
intercepts the packet and forward the packet to the home agent
through the IP-in-IP tunnel. The home agent then sends the packet out
to the intended recipient.
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It is the interest of this memo to investigate if such a
bi-directional tunneling approach can be extended to a mobile network
that is multi-homed. More specifically, we wish to identify issues
that may arise in bi-directional tunneling between mobile router and
home agent when the mobile network is multi-homed. To this end, this
memo first builds up a taxonomy on multi-homed mobile network.
Next, different deployment scenario are described for different
configurations of the multi-homed mobile network.
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2. Taxonomy
2.1 Explanations of Terms and Illustrations
This section describe items and abbreviations used in the
illustrations of this Internet Draft.
2.1.1 Abbreviations
Referring to the terminology of Network Mobility [2], the following
abbreviations are used in figures illustrated throughout this draft:
MR: Mobile Router
HA: Mobile Network Home Agent
AR: Access Router
MNN: Mobile Network Node
2.1.2 Illustrations
In all figures illustrated in this draft, the following convention
will be used.
_
-|_|-
R
R is a router.
p
| <-_
|--|_|-
|
L R
R advertised the Network Prefix p in the network link L.
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p1,p2
| <-_
|--|_|-
|
L
R
R advertised the Network Prefixes p1 and p2 in the network link L and
p1 and p2 are different. [Todo: Different how ? 64 first bits
different is enough or not ?]
_ |
-|_|=|
|
R
R is a router with two or more global addresses on one interface, or
with two or more interfaces on the same link, or two or more
interfaces on different links.
So the [=] symbol can be one of this cases:
- Multi-Addressed MR.
AR2
p2
_ <-_ _____
|_|-| _ |-|_|-| |
_ |-|_|-| _ | |
|_|-| |-|_|-|_____|
<-
p1
MNNs MR AR1 Internet
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- Multi-Egress-Interfaced MR on the same link: [Todo: Add
"Multi-Egress-Interfaced" term in the [Nemo-Term] ?]
_ __| _____
|_|-| _ / | _ | |
_ |-|_| |-|_|-| |
|_|-| \__| |_____|
|
MNNs MR AR Internet
- Multi-Egress-Interfaced MR on different links:
AR2
_ __| _ _____
|_|-| _ / |-|_|-| |
_ |-|_| _ | |
|_|-| \__|-|_|-|_____|
|
MNNs MR AR1 Internet
2.2 Classifications of Multi-homed Mobile Network.
There are various configurations of a multi-homed mobile network,
depending on how many mobile routers are present, how many egress
interfaces and home addresses the mobile routers have, how many
subnet prefixes are advertised to the mobile network nodes, etc. In
order to facilitate discussions on multi-homed mobile network, it is
necessary to identify what kind of configuration the mobile network
is in. Here, we identify three key parameters differentiating
different multi-homed configurations. With these parameters, we can
refer to each configuration by the 3-tuple (w,x,y), where 'w', 'x',
'y' are defined as follows:
o 'w' differentiates the case of single mobile router (with multiple
egress interfaces or multiple home addresses) versus the case of
multiple mobile routers, where
w=0 implies a mobile network has only a single mobile router. In
this case, the mobile router either has multiple egress
interfaces or multiple home addresses bound to a single egress
interface.
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w=1 implies a mobile network has more than one mobile router
advertising an egress route.
o 'x' differentiates the case of a single home agent for the mobile
network versus the case of multiple home agents for the mobile
network, where
x=0 implies that a single home agent is assigned to manage binding
updates of the mobile network.
x=1 implies that more than one home agents (possibly in different
administrative domains) manage the binding updates of the
mobile network.
o 'y' differentiates the case of single mobile network prefix versus
multiple mobile network prefixes that is/are advertised to the
mobile network node, where
y=0 implies that a single subnet prefix is advertised to the
mobile network nodes.
y=1 implies that more than one subnet prefixes are advertised to
the mobile network nodes.
It can be seen that the above three parameters are fairly orthogonal
to one another. Thus different values of 'w', 'x' and 'y' give rise
to different combinations of the 3-tuple (w,x,y). A total of 8
possible configurations can be identified. These are described
further in the following sub-sections.
2.2.1 (0,0,0): Single MR, Single HA, Single Prefix
The (0,0,0) mobile network has only one mobile router advertising a
single subnet prefix. In addition, the mobile router associates with
only one home agent at any one time. This makes the mobile network
very similar to a non-multi-homed mobile network, except for the fact
that the mobile router may either (i) use more than one egress links
at the same time, or (ii) use more than one home address at the same
time.
Since only one subnet prefix is advertised, the mobile network nodes
are (usually) not multi-homed.
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_____
_ p _ | |
|_|-|<-_ |-|_|-| |-| _
_ |-|_|=| |_____| | _ |-|_|
|_|-| | |-|_|-|
|
MNNs MR AR Internet AR HA
2.2.2 (0,0,1): Single MR, Single HA, Multiple Prefixes
The (0,0,1) mobile network has only one mobile router, which
associates to only one home agent at any one time. However, two or
more subnet prefixes are advertised to the mobile network nodes. No
associations is assumed between the subnet prefixes and the home
addresses of the mobile router.
Since a plurality of subnet prefixes are advertised, mobile network
nodes can generally be multi-homed themselves, where each mobile
network node is allocated one address in each subnet prefix.
_____
_ p1,p2 _ | |
|_|-|<-_ |-|_|-| |-| _
_ |-|_|=| |_____| | _ |-|_|
|_|-| | |-|_|-|
|
MNNs MR AR Internet AR HA
2.2.3 (0,1,0): Single MR, Multiple HAs, Single Prefix
The (0,1,0) mobile network has only one mobile router advertising a
single subnet prefix. The mobile router, however, associates to
multiple home agents, possibly one home agent per home addresses. No
assumption is made on whether or not the home agents belongs to the
same administrative domain.
Since only one subnet prefix is advertised, the mobile network nodes
are (usually) not multi-homed.
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AR HA2
_ |
|-|_|-| _
_____ | |-|_|
_ p _ | |-|
|_|-|<-_ |-|_|-| |
_ |-|_|=| |_____|-| _
|_|-| | | _ |-|_|
|-|_|-|
|
MNNs MR AR Internet AR HA1
2.2.4 (0,1,1): Single MR, Multiple HAs, Multiple Prefixes
The (0,1,1) mobile network has only one mobile router. However, the
mobile router advertises more than one subnet prefix, and also
associates to multiple home agents at the same time, possibly one
home agent per home address. No assumptions is made on whether or
not the home agents belongs to the same administrative domain.
Since a plurality of subnet prefixes are advertised, mobile network
nodes can generally be multi-homed themselves, where each mobile
network node is allocated one address in each subnet prefix.
AR HA2
_ |
|-|_|-| _
_____ | |-|_|
_ p1,p2 _ | |-|
|_|-|<-_ |-|_|-| |
_ |-|_|=| |_____|-| _
|_|-| | | _ |-|_|
|-|_|-|
|
MNNs MR AR Internet AR HA1
2.2.5 (1,0,0): Multiple MRs, Single HA, Single Prefix
The (1,0,0) mobile network has more than one mobile router
advertising global routes. These mobile routers, however, advertise
the same subnet prefix and associate to the same home agent. Since
only one subnet prefix is advertised, the mobile network nodes are
(usually) not multi-homed.
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MR2
p
<-_ |
_ |-|_|-| _____
|_|-| |-| |
_ | | |-| _
|_|-| _ |-|_____| | _ |-|_|
|-|_|-| |-|_|-|
<- | |
p
MNNs MR1 Internet AR HA
2.2.6 (1,0,1): Multiple MRs, Single HA, Multiple Prefixes
The (1,0,1) mobile network has more than one mobile router
advertising different global routes and different subnet prefixes.
However, these mobile routers associate to the same home agents.
Since a plurality of subnet prefixes are advertised, mobile network
nodes can generally be multi-homed themselves, where each mobile
network node is allocated one address in each subnet prefix.
MR2
p2
<-_ |
_ |-|_|-| _____
|_|-| |-| |
_ | | |-| _
|_|-| _ |-|_____| | _ |-|_|
|-|_|-| |-|_|-|
<- | |
p1
MNNs MR1 Internet AR HA
2.2.7 (1,1,0): Multiple MRs, Multiple HAs, Single Prefix
The (1,1,0) mobile network has more than one mobile router
advertising different global routes. The mobile routers are also
associated to more than one home agents at any one time. No
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assumptions is made on whether or not the home agents belongs to the
same administrative domain. However, the mobile routers advertises
the same subnet prefix. Since only one subnet prefix is advertised,
the mobile network nodes are (usually) not multi-homed.
MR2 AR HA2
p _ |
<-_ | |-|_|-| _
_ |-|_|-| _____ | |-|_|
|_|-| |-| |-|
_ | | |
|_|-| _ |-|_____|-| _
|-|_|-| | _ |-|_|
<- | |-|_|-|
p |
MNNs MR1 Internet AR HA1
2.2.8 (1,1,1): Multiple MRs, Multiple HAs, Multiple Prefixes
The (1,1,1) mobile network has more than one mobile router
advertising different global routes and different subnet prefixes.
The mobile routers are also associated to more than one home agent at
any one time. No assumptions is made on whether or not the home
agents belongs to the same administrative domain.
Since a plurality of subnet prefixes are advertised, mobile network
nodes can generally be multi-homed themselves, where each mobile
network node is allocated one address in each subnet prefix.
MR2 AR HA2
p2 _ |
<-_ | |-|_|-| _
_ |-|_|-| _____ | |-|_|
|_|-| |-| |-|
_ | | |
|_|-| _ |-|_____|-| _
|-|_|-| | _ |-|_|
<- | |-|_|-|
p1 |
MNNs MR1 Internet AR HA1
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2.3 Alternative Classifications
In the mailing list, Pascal Thubert (Cisco System) proposed an
alternative classification. He has a set of 4 categories, based on
two orthogonal parameters: the number of home agents, and the number
of subnet prefixes advertised. Since the two parameters are
orthogonal, the categories are not mutually exclusive. The four
categories are:
o Tarzan: Single HA for Different Care-ofs of Same Prefix
This is the case where one mobile router registers different
care-of-addresses to the same home agent for the same subnet
prefix. This is equivalent to the case of x=0, i.e. the (0,0,*)
mobile network.
o JetSet: Multiple HA for Different Care-ofs of Same Prefix
This is the case where the mobile router registers different
care-of-addresses to different home agents for the same subnet
prefix. This is equivalent to the case of x=1, i.e. the (0,1,*)
mobile network.
o Shinkansen: Single Prefix Advertised by Mobile Router(s)
This is the case where one subnet prefix is announced by different
mobile routers. This is equivalent to the case of y=0, i.e. the
(1,*,0) mobile network.
o DoubleBed: Multiple Prefixes Advertised by Mobile Router(s)
This is the case where more than one subnet prefixes are announced
by the different mobile routers. This is equivalent to the case
of y=0, i.e. the (1,*,1) mobile network.
Thubert's classifications is problem-oriented, as oppose to the 8
classifications in this draft, which are configurations oriented. We
see also that one can draw association between some of the 8
classifications in this draft with the each of the 4 categories put
forward by Thubert. Hence, in a rough manner, one can say the 4
classes drawn by Thubert is actually a subset of the 8 configurations
defined, though such an associations is a vague one since both
partitioned the multi-homed mobile network differently
(problem-oriented versus configuration-oriented).
It is, however, the authors' belief that by analyzing each
configurations, problems and issues of multi-homed mobile network can
be more thoroughly identified. It may well be that after analysis,
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we come to the same 4 specific problems Thubert has identified. Even
so, the exercise of analysis each configuration should be helpful to
the understanding of each problem.
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3. Deployment Scenarios
[ To be re-organized -- cwng ]
One example of the (0,0,*) mobile network is that a single Internet
Service Provider (ISP) offers two different wireless public access
methods such as IEEE 802.11 and GPRS. A mobile router with both
access interfaces (i.e. 802.11 and GPRS capabilities) may subscribe
to the same ISP and is allowed to use both access methods. The ISP
will choose to provide a single home agent for the same mobile router
for ease of management.
This configuration is useful for maintaining connectivity between
several interfaces. An example will be to use 802.11 in town and
GPRS in the country side. In addition, it can also provide some
multi-homing benefits (such as Fault-Tolerance / Policy Sharing) to
MNNs without having to involve the MNNs.
Extending the above example to a (0,1,*) mobile network, the mobile
router may subscribe to different ISPs for different access
technologies. For instance, it may subscribe to 802.11 public access
services using one ISP, and subscribe to GPRS services from another
ISP. In this case, the two different ISPs will provide two different
home agents for the same mobile router. Since the two ISPs are
independent, under normal situation, each ISP will delegates
different subnet prefixes to the mobile network, thus forming a
(0,1,1) mobile network.
An example of the (1,*,*) mobile network is when a mobile network
contains more than one device with independent routes to the global
Internet. An excellent illustration is the Wireless Personal Area
Network (W-PAN) where a mobile phone on the W-PAN connects to the
Internet via GPRS services, and a Personal Digital Assistant (PDA) on
the same W-PAN connects to the Internet via 802.11 public access. If
the ISPs provide both access technologies, then the subscriber can
subscribes to a all-in-one package where the ISP provides a single
home agent to manage the mobile network, and delegates a single
subnet prefix to the mobile network. This forms a (1,0,0) mobile
network. Alternatively, the subscriber can subscribes to two ISPs for
each access mechanism, thus giving a (1,1,1) mobile network.
The (1,*,0) configuration provides easily a router redundancy and/or
HA redundancy for big mobile networks, such as within a train or a
plane, or critical mobile networks, such as those deployed in
ambulances, fire engines, or military vehicles.
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Deployment example for (0,1,0) [~JetSet]
[The Jet]
_ |\_______ _
-|_|- <--------------> |____~___\ <--> -|_|-
HA1 MN inside the HA2
plane.
Paris New York
In this example, the MR sends the same PBU to both HAs in different
cities, and communicates with both simultaneously. Thus a
Correspondent Node near Paris can choose the Paris's HA to send its
packets, and the MR inside the plane should send its packet to the
New York's HA (which is nearer).
Example for a (*,*,1) mobile network is a car network, where there
may be different logical subnets:
o the User Network which provides Internet connectivity to
passengers;
o the Control Network which exchanges car information (e.g.
position, movement, intern constants) with the others cars, or
with the society who use this car; and
o the Safeguard Network which shares state information of the car
with the emergency/repairing companies, or the emergency agencies
in case of accidents.
Because of these differences it can be useful to attribute a
different network prefix for each network to clearly separate each
entity and each network prefix should be send to a different subnet
link.
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4. Analysis
[ This section is hastily set up for the benefit of the solution
design team. This section will be re-organized in the next version --
cwng ]
This section, we attempt to analyze what are the problems faced in
each of the 8 categories. It shouldn't matter if some of the
categories share the same problem(s).
o (0,0,0) Mobile Network
The (0,0,0) mobile network has only one mobile router registering
more than one care-of-addresses to the same home agent, and
advertising only one prefix. The mobile router can either have
more than one care-of-addresses bound to the same home-address, or
it can have various care-of-address and home-address pairs.
Either way, this is a MIPv6 problem. Multiple pairs of different
care-of-address and home-address is perfectly alright with MIPv6.
The fact that they specify the same subnet prefix in binding
updates shouldn't cause a problem either. Having a home-address
tied to multiple care-of-address may be a problem for MIPv6. This
will require a solution like [10].
o (0,0,1) Mobile Network
The (0,0,1) mobile network is similar to the (0,0,0) mobile
network, and thus face the same problem when there is only one
home-address bound to multiple care-of-addresses. However, the
(0,0,1) has one NEMO-specific problem if more than one subnet
prefixes are being taken care-of by a single home-address and
care-of-address pair. This is assuming prefix-scoped binding
update is used, which does not allow more than one prefix be
specified in a single binding update.
o (0,1,0) Mobile Network
The (0,1,0) mobile network has one mobile router registering to
multiple home agents. There is the question of whether a mobile
router can register the same home-address to different home agents
simultaneously with the 'H' bit set. If not, the mobile router
can only register different home-address and care-of-address pairs
to different home agents. In any case, this is a MIPv6 issue.
The NEMO-specific problem is the fact that a subnet prefix has a
care-of in different home agents. It might be possible that only
one home-agent will actively advertise a route to the subnet
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prefix. The case of multiple home agents at different domains
advertising a route to the same subnet prefix may pose a problem
in the routing infrastructure as a whole. The implications of
this aspect needs further exploration.
o (0,1,1) Mobile Network
The (0,1,1) mobile network has one mobile router registering to
multiple home agents multiple subnet prefixes. The same question
of whether the same home-address can be simultaneously registered
to multiple home agents.
This (0,1,1) network can avoid the problem of registering care-ofs
for the same prefix to different home agents by registering
care-of for one prefix at one home-agent.
o (1,0,0) Mobile Network
The (1,0,0) mobile network has two or more active egress mobile
routers, registering to same home agents, and advertising the same
prefix. May not have any problem at all if the mobile routers are
manually configured to announce the same prefix. It is also
possible that prefix delegation is used to ensure all routers
advertise the same subnet prefix since all routers are handled by
the same home agent. The home-agent will see two HoA-CoA pairs
taking care of the same subnet prefix.
o (1,0,1) Mobile Network
The (1,0,1) mobile network has multiple active egress mobile
routers registering to the same home-agent, and advertising
multiple prefixes. If a mobile router is advertising more than one
prefix, we have the same problem as (0,0,1) as in how to register
more than one subnet prefix to the same home-agent.
On the other hand, if each mobile router take cares of a separate
(and only one) subnet prefix, then there should not be any
NEMO-specific problem.
o (1,1,0) Mobile Network
The (1,1,0) mobile network has multiple mobile routers registering
to different home agents, but advertising the same prefix. There
is the same issues as in (0,1,0) of a subnet prefix having a
care-of in different home agents. In addition, there is a
question how to perform prefix delegation such that two home
agents will delegate the same prefix to different mobile routers.
Certain level of home-agent co-ordination may be required here.
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o (1,1,1) Mobile Network
The (1,1,1) mobile network has multiple mobile routers,
registering to multiple home-agents and advertising prefixes.
This may be a case of multiple non-multi-homed network
superimposed together, i.e. each mobile router take cares of one
prefix, and register to separate home agents.
On the other hand, if one mobile router takes cares of more than
one prefix, we have similar problems as (0,0,1) and (1,0,1). In
addition, if more than one mobile router takes care of the same
prefix, we have similar issues as (1,1,0). In any case, we see
that the problems within this configurations can be decomposed
into problems from other configurations.
From the above analysis, we can identify the following problems
relating to multi-homed mobile network:
o Multiple care-of-addresses to one home-address:
* How to register two care-of-address binding to one
home-address?
* In single or multiple binding message(s)?
* How to selectively update a care-of-address?
* MIPv6 specific?
* Wakikawa's draft [10] specifically addresses this issue.
o Multiple prefixes taken care of by a single home-address:
* How to register multiple prefix scope under the same
home-address?
* In single or multiple binding message(s)?
* How to selectively update the care-of of a subnet prefix?
* Similar to the 'Tarzan' problem illustrated by Thubert.
o A single home-address registered to multiple home agents:
* Is this allowed?
* MIPv6-specific?
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o A single subnet prefix registered to multiple home agents:
* Is this allowed?
* Is this allowed if the prefix is bound to the same
home-address?
* Any routing issue?
* If prefix delegation is used, possibility of requiring home
agents co-ordination.
* Similar to the 'JetSet' problem illustrated by Thubert.
o A single prefix advertised by multiple mobile routers from
multiple home agents:
* If prefix delegation is used, possibility of requiring home
agents co-ordination.
* Similar to the 'Shinkansen' problem illustrated by Thubert.
o [TBD: anymore]
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5. Security Considerations
This document is an on-going work to classify the taxonomy in
multi-homing of mobile networks. There should be a separate draft
produced by the working group to analyze security threats for network
in motion. As such, no special security considerations is listed
here. However, since this memo also looks into the analysis of
problems in a multi-homed mobile network, we will add problems
related to security threat here as and when they are encountered. We
also encourage interested readers to contribute to this part.
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6. Acknowledgements
The authors would like to thank people who have given valuable
comments on various multi-homing issues on the mailing list, and also
those who have suggested directions in the 56th IETF Meeting.
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References
[1] Ernst, T., et al, "Network Mobility Support Goals and
Requirements", Internet Draft:
draft-ietf-nemo-requirements-01.txt, Work In Progress, May
2003.
[2] Ernst, T. and H. Lach, "Network Mobility Support Terminology",
Internet Draft: draft-ietf-nemo-terminology-00.txt, Work In
Progress, May 2003.
[3] Perkins, C., "IP Mobility Support for IPv4", RFC 3344, August
2002.
[4] Johnson, D. B., Perkins, C. E. and Arkko, J., "Mobility Support
in IPv6", Internet Draft: draft-ietf-mobileip-ipv6-21.txt, Work
In Progress, February 2003.
[5] Conta, A. and Deering, S., "Generic Packet Tunneling in IPv6",
IETF RFC 2473, December 1998.
[6] Kniveton, T. J., et al, "Mobile Router Tunneling Protocol",
Internet Draft: draft-kniveton-mobrtr-03.txt, Work In Progress,
November 2002.
[7] Petrescu, A., et al, "Issues in Designing Mobile IPv6 Network
Mobility with the MR-HA Bidirectional Tunnel (MRHA)", Internet
Draft: draft-petrescu-nemo-mrha-00.txt, Work In Progress,
October 2002.
[8] Ng, C. W. and Tanaka, T., "Securing Nested Tunnels Optimization
with Access Router Option", Internet Draft:
draft-ng-nemo-access-router-option-00.txt, Work In Progress,
October 2002.
[9] Wakikawa, R., et al, "Basic Network Mobility Support", Internet
Draft: draft-wakikawa-nemo-basic-00.txt, Work In Progress,
February 2003.
[10] Wakikawa, R., et al, "Multiple Care-of-Address Registration on
Mobile IPv6", Internet Draft:
draft-wakikawa-mobileip-multiplecoa-00.txt, Work In Progress,
February 2003.
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Authors' Addresses
Chan-Wah Ng
Panasonic Singapore Laboratories Pte Ltd
Blk 1022 Tai Seng Ave #06-3530
Tai Seng Industrial Estate
Singapore 534415
SG
Phone: +65 65505420
EMail: cwng@psl.com.sg
Julien Charbon
Keio University, Louis Pasteur University
Keio University.
5322 Endo
Fujisawa-shi, Kanagawa 252-8520
JP
Phone: +81-466-49-1100
Fax: +81-466-49-1395
EMail: julien@sfc.wide.ad.jp
URI: http://www.sfc.wide.ad.jp/~julien/
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