NEMO Working Group J. Charbon
Internet-Draft Keio university, Louis Pasteur
Expires: December 30, 2003 university and WIDE
C-W. Ng
Panasonic Singapore Labs
K. Mitsuya
T. Ernst
Keio university and WIDE
July 1, 2003
Evaluating Multi-homing Support in NEMO Basic Solution
draft-charbon-nemo-multihoming-evaluation-00
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Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
This draft describes and explains prerequisites for NEMO Basic to
support Multi-homing. We study those prerequisites with respect to
each case of a taxonomy proposed to the NEMO WG and we analyze how
the NEMO basic support solution fits with them. The analysis of each
case listed in this taxonomy is broken into three parts,
prerequisites, comments, and solution behaviors.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Context and Motivations . . . . . . . . . . . . . . . . . . . 4
1.2 Terms and Abbreviations . . . . . . . . . . . . . . . . . . . 4
1.3 Multi-Homing & Support levels . . . . . . . . . . . . . . . . 4
1.4 Organization . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Case (0,0,0) . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 Solution behaviors . . . . . . . . . . . . . . . . . . . . . . 10
3. Case (1,0,0) . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.3 Solution behaviors . . . . . . . . . . . . . . . . . . . . . . 13
4. Case (0,1,0) . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . 14
4.2 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.3 Solution behaviors . . . . . . . . . . . . . . . . . . . . . . 16
5. Case (1,1,0) . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . 17
5.2 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.3 Solution behaviors . . . . . . . . . . . . . . . . . . . . . . 17
6. Case (0,0,1) . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.1 Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . 18
6.2 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6.3 Solution behaviors . . . . . . . . . . . . . . . . . . . . . . 18
7. Case (1,0,1) . . . . . . . . . . . . . . . . . . . . . . . . . 19
7.1 Solution requirements . . . . . . . . . . . . . . . . . . . . 19
7.2 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7.3 Solution behaviors . . . . . . . . . . . . . . . . . . . . . . 20
8. Case (0,1,1) . . . . . . . . . . . . . . . . . . . . . . . . . 21
8.1 Solution requirements . . . . . . . . . . . . . . . . . . . . 21
8.2 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
8.3 Solution behaviors . . . . . . . . . . . . . . . . . . . . . . 21
9. Case (1,1,1) . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.1 Solution requirements . . . . . . . . . . . . . . . . . . . . 22
9.2 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.3 Solution behaviors . . . . . . . . . . . . . . . . . . . . . . 22
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10. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 23
11. Security Considerations . . . . . . . . . . . . . . . . . . . 24
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 25
References . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 27
Intellectual Property and Copyright Statements . . . . . . . . 29
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1. Introduction
1.1 Context and Motivations
As specified in the NEMO Basic Support in Requirement R.12 [Section
5. NEMO Basic Support One-liner Requirements] [2], the NEMO WG must
ensure that the basic solution produced does not prevent the use of
Multi-homing. However the NEMO Basic support solution [1] does not
specify any particular mechanism to manage Multi-homing, but
discussion on this purpose is still open (see [Section 7. Extended
Home Network] [1]).
This draft complements [4], analyzes the behavior of NEMO Basic
Support [1] and deployment issues in different Multi-homing
scenarios. This analysis can provide a preliminary evaluation of the
NEMO basic support solution with respect to Multi-homing support for
further discussions.
It is assumed that the readers are familiar with the NEMO terminology
specified in [3] and the taxonomy described in [4].
1.2 Terms and Abbreviations
In addition to the terms defined in [3], we use the following
abbreviations in this memo:
Prefix-BU: Mobile Network Prefix Binding Update
1.3 Multi-Homing & Support levels
In order to evaluate the NEMO basic solution, the Multi-homing
support can be classified into three main categories:
o Fault-Tolerance/Redundancy:
As long as the Mobile Network maintains at least one connection to
the Internet, connectivity for all Mobile Nodes is guaranteed.
This behavior is separated into two sub-classes:
- Without transparency: The lost of one connection to the Internet
breaks transport sessions that use it; however, new transport
sessions are possible.
- With transparency: The lost of one connection to the Internet is
transparent for Layer 4 and above, i.e. lost of one connection
does not disrupt transport sessions.
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o Load-Sharing:
This is achieved when the traffic load is distributed among
different connections between the mobile network and the Internet.
Here, we do not indulge into the more exotic forms of load
balancing such as random selection, round-robin per-packet,
per-connection etc. As long as the protocol uses all active
connections simultaneously, Load-sharing will have been deemed
achieved.
The benefits of load sharing is studied for inbound and outbound
traffic.
o Policy:
The management of traffic can be done by any possible mechanism.
For example, it may depend on:
* The kind/cost of connection.
* Social policy based on schedule.
* The class of the avian carriers [8].
In fact, we only consider whether the solution provides a
mechanism to carry some policy informations - such as the Flow
Label in IPv6 header (see [Section 6. Flow Labels] [7]) - because
going deeper into analyzing the solutions for all policy cases is
too complex.
1.4 Organization
In the remaining sections of this draft, we will analyze the behavior
of NEMO basic support in each scenario from the Multi-homing taxonomy
[4]. The analysis of each is broken into three parts:
1. Prerequisites: Prerequisites for Multi-homing support and its
benefits against each classes defined above.
2. Comments: About prerequisites and deployment issues and other
things related.
3. Solution Behaviors: How the NEMO Basic current solution support
theses prerequisites.
The "Prerequisites" part is syntactical in nature, the "Comments"
part detailed, and the "Solution Behaviors" one technical.
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The first case is a long description since we have to explain the
prerequisites in detail. Thereafter, in subsequent sections we will
aggregate the prerequisites as much as possible.
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2. Case (0,0,0)
Illustration of the case:
_____
_ p _ | |
|_|-|<-_ |-|_|-| |-| _
_ |-|_|=| |_____| | _ |-|_|
|_|-| | |-|_|-|
|
MNNs MR AR Internet AR HA
2.1 Prerequisites
o Redundancy:
If an interface/link is broken, use the other: No additional
prerequisites at NEMO level. But for efficient support of this
benefit the layer 2 have to send interface/link informations or
orders to NEMO. And this redundancy is always transparent: Read
"Fault-Tolerance and the MNNs" in (Section 2.2).
But this behavior is not sufficient to respect the requirements:
Read "Load-sharing & Requirements" in (Section 2.2).
o Load-Sharing:
For this class the solution MUST at least:
1. Allows the use of several active bi-directional tunnels
simultaneously between MR and HA.
2. Allows the binding of multiple CoAs against the same MNP.
3. Provides a method to identify which CoA a Prefix-BU is meant
to update. Read "CoA Identification" in (Section 2.2).
In this case the MR and the HA MUST use the two bi-directional
tunnels simultaneously. Read "Load-sharing & Requirements" in
(Section 2.2).
* Outbound Traffic: The MR distributes between its CoAs.
There is no assumption on the distribution mechanism.
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* Inbound Traffic: The HA distributes between MR's CoAs.
The distribution can be statically fixed or be more dynamic: A
preference can be sent with each Prefix-BU to mark the
preference of each CoA in the HA's Binding Cache.
o Policy:
* Outbound Traffic: This behavior depends on the NEMO
implementation. No way to impose an algorithm.
* Inbound Traffic: Provide a policy field or policy sub-option
with each Prefix-BU to indicate a policy management for each
CoA to the HA.
2.2 Comments
o CoA Identification:
To illustrate this prerequisite, we consider the following
example:
The MR has two CoAs: CoA-1 and CoA-2. The HA have in its "NEMO
Binding Cache" - Here this is a logical view of this cache :
+=========================+=================+
| MNP/Prefix Length | Care Of Address |
+=========================+=================+
| MNP-1/Length-1 | CoA-1 |
+-------------------------+-----------------+
| MNP-1/Length-1 | CoA-2 |
+=========================+=================+
Then the HA receives a Prefix-BU which contains:
+=========================+=================+
| MNP/Prefix Length | Care Of Address |
+=========================+=================+
| MNP-1/Length-1 | CoA-New |
+=========================+=================+
The question is: Which CoA should CoA-New updates? CoA-1 or
CoA-2? The solution needs a way to differentiate each CoA
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binding.
o Load-sharing & Requirements:
Fault-Tolerance is not sufficient, in all configuration cases, to
conform to the Multi-Homing requirements defined in NEMO:
Referring to [Section 5. Multi-homing] [3] the definition of a
Multi-homed Mobile Router is:
A MR is multi-homed when it has simultaneously more than one
active connection to the Internet, [...]
And according to [Section 5. NEMO Basic Support One-liner
Requirements] [2]:
R12: The solution MUST function for multi-homed MR and
multi-homed mobile networks as defined in [NEMO-TERMS]).
Particularly:
R12.1: The solution MUST function for multi-MR mobile
networks
Thus the NEMO solution MUST manage network traffic
simultaneously through the several connection of a same MR.
o MR is the only one:
Here only the MR is Multi-Homed and thus depending on the desired
level of Multi-Homing, there exists several solutions to deal with
this case, such as [5] and [6] deal with Multi-Interface issue and
Mobility.
o Fault-Tolerance and the MNNs:
This configuration does not change anything on the behavior of
MNNs: the MNNs always send their packets to the same interface -
i.e. the ingress interface of MR. Thus the Fault-Tolerance with
Transparency benefit is naturally provided to the MNNs.
o Load-Sharing mechanisms:
The MR can use many algorithms to share the outbound traffic
according to administrator wishes. Same remark for each (0,*,*)
case.
For the inbound one, a preference can be sent with each Prefix-BU
to mark preference of each CoA in the HA's binding table, and thus
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HA can perform load sharing according to MR's preference. Same
remark for each (*,0,*) cases.
2.3 Solution behaviors
o Against Load-Sharing:
1. Doesn't specify the simultaneous use of several bi-directional
tunnels but doesn't prevent it.
2. Doesn't specify the binding of multiple CoAs against the same
MNP but doesn't prevent it.
3. Doesn't provides a method to identify each CoA but doesn't
prevent it:
Here an explanation of one of possibility of this management:
As long as there is no specific field for a CoA ID, the solution
have to use a field present in current Prefix-BU definition. The
only common field is each type of Prefix-BU - Implicit, Explicit
and Explicit combined - is the Home Address Option in the
Destination Option Header [Section 6.3 Home Address Option] [13].
Thus a NEMO implementation can create a Home Address for each
egress interface. And when a CoA on an egress interface change,
use in Prefix-BU the corresponding Home Address in the Home
Address Option. An example to make clear this behavior:
HA Routing Table & Binding Cache before:
+===============+=================+=========================+
| Home Address | Care-of Address | MN Prefix/Prefix Length |
+===============+=================+=========================+
| HoA-1 | CoA-1 | MNP-1/Length-1 |
| HoA-2 | CoA-2 | MNP-1/Length-1 |
+===============+=================+=========================+
Here HoA-x is the Home Address corresponding to the egress
interface x on which is assigned CoA-x. Now the HA receives a
Prefix-BU because CoA-1 has changed to CoA-New.
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The Prefix-BU:
+===============+=================+=========================+
| Home Address | Care-of Address | MN Prefix/Prefix Length |
+===============+=================+=========================+
| HoA-1 | CoA-New | MNP-1/Length-1 |
+===============+=================+=========================+
The HA updates the HoA-1 entry, and thus the CoA-1 binding.
Routing Table & Binding Cache after:
+===============+=================+=========================+
| Home Address | Care-of Address | MN Prefix/Prefix Length |
+===============+=================+=========================+
| HoA-1 | CoA-New | MNP-1/Length-1 |
| HoA-2 | CoA-2 | MNP-1/Length-1 |
+===============+=================+=========================+
You can see the difference with "CoA Identification" (Section
2.2).
And an example of creation of Home Address according to egress
interface can be:
Egress Interface 1 -> EUI-64-1 ->
Home Address for this interface: MNP:EUI-64-1
Egress Interface 2 -> EUI-64-2 ->
Home Address for this interface: MNP:EUI-64-2
Maybe the solution should specify this behavior because it is
very specific to NEMO.
o Against dynamic Load-sharing and Policy:
The solution didn't specify anything about a kind of preference/
policy field, but maybe an NEMO implementation can use some part
of the reserved field in the MNP Option [Section 4.3. Mobile
Network Prefix Option] [1] or in a sub-option.
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3. Case (1,0,0)
Illustration of the case:
MR2
p
<-_ |
_ |-|_|-| _____
|_|-| |-| |
_ | | |-| _
|_|-| _ |-|_____| | _ |-|_|
|-|_|-| |-|_|-|
<- | |
p
MNNs MR1 Internet AR HA
3.1 Prerequisites
For this case the solution MUST at least support all prerequisites
from (Section 2.1).
Differences with (0,0,0) case:
o Load-sharing:
For outbound traffic the MNNs distribute outgoing packets between
the MRs.
This kind of sharing is out of scope of NEMO WG. Read
"Load-Sharing for Outbound Traffic" in (Section 3.2).
3.2 Comments
o Fault-Tolerance is already done:
Here all MNNs operate a selection of default router [Section
6.3.6. Default Router Selection] [9] which provide
Fault-Tolerance benefit.
Note: Depending on the implementation and the type of traffic this
mechanism can be acceptable or too slow [Section 7.3. Neighbor
Unreachability Detection] [9].
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o Load-Sharing for Outbound Traffic:
In this case, how to provide this benefit is not in the scope of
NEMO Working Group. Anyway a good idea can be: [Default Router
Preferences, More-Specific Routes, and Load Sharing] [10]. This
solution can be considered for each (1,*,*) cases.
3.3 Solution behaviors
Same behaviors as in (Section 2.3).
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4. Case (0,1,0)
Illustration of the case:
AR HA2 [Manage CoAx]
_ |
|-|_|-| _
_____ | |-|_|
_ p _ | |-|
|_|-|<-_ x|-|_|-| |
_ |-|_|=| |_____|-| _
|_|-| y| | _ |-|_|
|-|_|-|
|
MNNs MR AR Internet AR HA1 [Manage CoAy]
4.1 Prerequisites
o Redundancy:
Same as "Reduncancy" in (Section 2.1).
o Load-Sharing:
In this case the MR and the HAs MUST use the two bi-directional
tunnels simultaneously. Read "Load-sharing & Requirements" in
(Section 2.2).
* Outbound Traffic: The MR distribute between its CoAs.
There is no assumption on the distribution mechanism.
* Inbound Traffic: The CNs distribute between the two HAs.
No prerequisites at NEMO level for static Load-sharing and for
dynamic one read "Interaction with routing protocols" in
(Section 4.2).
o Policy:
* Outbound Traffic: This behavior is dependent on the NEMO
implementation. No way to impose an algorithm.
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* Inbound Traffic: Close to Load-sharing prerequisite. Thus read
"Interaction with routing protocols" in (Section 4.2).
4.2 Comments
o Interaction with routing protocols:
The main goal of this case is to provide HA redundancy and a kind
of Routing Optimization. And here both HAs announce the same MNP.
So:
* The two HAs are in the same IGP domain:
Each HA advertise the same MNP via the IGP routing protocol.
The metric/cost used for these advertisements can be statically
configured on the HA or dynamically by MR which sending a kind
of "priority" - to make the difference with the "preference"
field cited above - information to each HAs. For example this
information can inside the Prefix-BU as sub-option. This idea
come from Ryuji Wakikawa.
* Is possible that theses HAs can be in different AS?
Yes, read [Section 5.1.2. Possibly Multihomed, An Identical
Prefix from a Different Origin] [11].
Advantage:
+ The inbound traffic always going to the cheapest HA
according to the BGP policy of the CN domain.
Inconvenient:
+ This route should be published in the Internet Route
Registry for the two AS. Elsewhere, these announcement can
be deleted by mechanism which are used to fight "route
hijacking" in BGP.
+ The route optimization effect is only available for the
inbound traffic.
+ The BGP protocol announce only one route, thus the CN has no
"real" choice. The choice is made by the border router of
the CN's AS.
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o Routing Optimization:
If the goal is to provide a pure Routing Optimization - for
inbound and outbound traffic - the solution has to establish a
kind of Inter-HA protocol. But it's too early to say if this
behavior have to be supported by NEMO Basic Support.
In conclusion, there is no strong prerequisite at NEMO level, but
some at deployment one.
4.3 Solution behaviors
o Against Redundancy:
The proposed solution should work without any changes.
o Against Load-sharing and Policy:
The solution doesn't provide any "priority" carriage to the HAs to
influence the routing announces thus dynamic Load-sharing for
inbound traffic is not provided.
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5. Case (1,1,0)
Illustration of the case:
MR2 AR HA2 [Manage MR2]
p _ |
<-_ | |-|_|-| _
_ |-|_|-| _____ | |-|_|
|_|-| |-| |-|
_ | | |
|_|-| _ |-|_____|-| _
|-|_|-| | _ |-|_|
<- | |-|_|-|
p |
MNNs MR1 Internet AR HA1 [Manage MR1]
5.1 Prerequisites
For this case the solution just have to:
o Refer to "Comments" in (Section 4.2) and in "Fault-Tolerance is
already done" at (Section 3.2).
5.2 Comments
Load-Sharing distribution:
For Outbound Traffic:
The MNNs distribute traffic between the two MRs.
For Inbound Traffic:
The CNs distribute traffic between the two HAs.
5.3 Solution behaviors
Same behaviors as in (Section 4.3).
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6. Case (0,0,1)
Illustration of the case:
_____
_ p1,p2 _ | |
|_|-|<-_ |-|_|-| |-| _
_ |-|_|=| |_____| | _ |-|_|
|_|-| | |-|_|-|
|
MNNs MR AR Internet AR HA
6.1 Prerequisites
For this case the solution MUST at least support all prerequisites
from (Section 2.1).
6.2 Comments
o Source Address selection:
Each MNN gets two global addresses and thus performs Source
Address Selection [12].
o Load-Sharing distribution:
For Outbound Traffic:
The MR distributes traffic between its two CoAs.
For Inbound Traffic:
The HA distributes traffic between the two MR's CoAs.
6.3 Solution behaviors
Same behaviors as in (Section 2.3).
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7. Case (1,0,1)
Illustration of the case:
MR2
p2
<-_ |
_ |-|_|-| _____
|_|-| |-| |
_ | | |-| _
|_|-| _ |-|_____| | _ |-|_|
|-|_|-| |-|_|-|
<- | |
p1
MNNs MR1 Internet AR HA
7.1 Solution requirements
For this case, the solution MUST at least do nothing special because
for the HA, the Mobile Network is seen like two distinct Mobile
Network.
7.2 Comments
o Source Address selection:
Each MNN gets two global addresses and thus performs Source
Address selection. However, the MRs or the HA can apply some kind
of Ingress Filtering - like Reverse Path Filtering or other - and
depending on the routing protocol configuration, a MR/the HA can
refuse to forward packets with a different source prefix other
than the MR advertised MNP. In [Section 7. Interactions with
Routing] [12]:
"Implementations may also use the choice of router to influence
the choice of source address. For example, suppose a host is on a
link with two routers. One router is advertising a global prefix
A and the other router is advertising global prefix B. Then when
sending via the first router, the host may prefer source addresses
with prefix A and when sending via the second router, prefer
source addresses with prefix B."
Thus care must be taken when configuring MRs and routing protocol
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behavior between MRs and HA.
o Redundancy without transparency:
Suppose MR1 or the tunnel between MR1 and HA goes down, the MNNs
that choose the p1 prefixed source address will lose their
connections because they - if ingress filtering - can't send
theses packets to MR2. But new connections are still possible by
using the other source address corresponding to the prefix
advertised by MR2 (i.e. p2). But the time to switch source
address can be very long: the non-usable source address will have
to become deprecated [5. Source Address Selection] [12].
Providing this kind of transparency is out of scope of NEMO Basic.
For MNNs that act as a Mobile Host this issue should be solved in
the Mobile-IP Working Group.
o Load-Sharing distribution:
For Outbound Traffic:
The MNNs distribute traffic between the two MRs.
For Inbound Traffic:
The HA distributes traffic between the CoAs of each MR.
7.3 Solution behaviors
The default behavior is enough to support this case.
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8. Case (0,1,1)
Illustration of the case:
AR HA2 [Manage p2]
_ |
|-|_|-| _
_____ | |-|_|
_ p1,p2 _ | |-|
|_|-|<-_ |-|_|-| |
_ |-|_|=| |_____|-| _
|_|-| | | _ |-|_|
|-|_|-|
|
MNNs MR AR Internet AR HA1 [Manage p1]
8.1 Solution requirements
Nothing special because each HA see the same Mobile Network but
through its own Mobile Network Prefix.
8.2 Comments
o Redundancy without transparency:
If HA1 or the tunnel between HA1 and the MR goes down, the MNNs
that choose p1 prefixed source address will lose theirs
connections because MR can't forward these packets to the HAy -
because of the Ingress Filtering made by ISP of HA2. But new
connections are possible by switching to the source address with
the other mobile network prefix (i.e. p2). Again, we have the
penalty of switching source addresses.
o Load-Sharing distribution:
For Outbound Traffic:
The MR distributes traffic between its two CoAs.
For Inbound Traffic: The CNs distribute between the two HAs.
8.3 Solution behaviors
The default behavior is enough to support this case.
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9. Case (1,1,1)
Illustration of the case:
MR2 AR HA2 [Manage MR2]
p2 _ |
<-_ | |-|_|-| _
_ |-|_|-| _____ | |-|_|
|_|-| |-| |-|
_ | | |
|_|-| _ |-|_____|-| _
|-|_|-| | _ |-|_|
<- | |-|_|-|
p1 |
MNNs MR1 Internet AR HA1 [Manage MR1]
9.1 Solution requirements
Nothing special because each HA see the same Mobile Network but
through its own MR.
9.2 Comments
o Redundancy without transparency:
If MR1 or HA1 or the tunnel between MR1 and HA1 goes down, the
MNNs that choose p1 prefixed source address will lose their
connections because they can't send theses packets to the MR2 -
the Ingress Filtering made by ISP of HA2. But new connections are
possible by using the source address corresponding to the MNP
advertised by MR2 (i.e. p2).
o Load-Sharing distribution:
For Outbound Traffic: The MNNs distribute between the two MRs.
For Inbound Traffic: The CNs distribute between the two HAs.
9.3 Solution behaviors
The default behavior is enough to support this case.
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10. Conclusions
In this draft, we explore the level of Multi-homing support available
in the NEMO Basic proposed solution with respect to Multi-homing
requirements, the main goal being:
"Do not prevent Multi-homing configurations/benefits by the using of
NEMO Basic Support."
and this goal is mainly respected. However, based on our analysis,
we propose some improvements.
o Preference & Priority:
Theses two informations permit to manage the sharing/the policy of
the Inbound traffic to the Mobile Network through several CoAs
and/or several HAs.
Theses information could be added to the Prefix-BU, and the
proposed solution specify a field/an sub-option to permit some
implementation to provide this benefit; or specify in the next
release of NEMO protocol.
o Multiple CoAs for the same MNP:
The proposed solution doesn't have to specify anything one this
subject, just to support it. But a paragraph on this purpose can
be helpful for implementation's developers.
The problem of Multi-homing in Network Mobility covers many
specifications and network domains, which makes the ideas about this
subject interesting but difficult to fix. We hope that this document
can trigger further discussions on the Multi-homing aspect of NEMO
basic solution.
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11. Security Considerations
This document is an on-going work to evaluate the degree of
Multi-homing support in NEMO solutions. 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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12. Acknowledgements
The authors would like express their appreciation to Ryuji Wakikawa
and Pascal Thubert for their significant comments on this document.
The authors would also like to extend their gratitude to people who
have given valuable comments on various Multi-homing issues on the
mailing list.
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References
[1] Devarapalli, V., Wakikawa, R., Pestrescu, A. and P. Thubert,
"Nemo Basic Support Protocol", Internet Draft:
draft-ietf-nemo-basic-support-00.txt, Work In Progress, June
2003.
[2] Ernst, T., et al, "Network Mobility Support Goals and
Requirements", Internet Draft:
draft-ietf-nemo-requirements-01.txt, Work In Progress, May
2003.
[3] Ernst, T. and H-Y. Lach, "Network Mobility Support
Terminology", Internet Draft:
draft-ietf-nemo-terminology-00.txt, Work In Progress, May 2003.
[4] Ng, C-W. and J. Charbon, "Multi-Homing Issues in Bi-directional
Tunneling", Internet Draft:
draft-ng-nemo-multihoming-issues-01, Work In Progress, May
2003.
[5] Wakikawa, R., Uehara, K. and T. Ernst, "Multiple
Care-of-Address Registration on Mobile IPv6", Internet Draft:
draft-wakikawa-mobileip-multiplecoa-01.txt, Work In Progress,
June 2003.
[6] Montavont, N. and T. Noel, "MIPv6 for Multiple Interfaces",
Internet Draft: draft-montavont-mobileip-mmi-00.txt, Work
Expired, Jully 2002.
[7] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6)
Specification", RFC 2460, December 1998.
[8] Waitzman, D., "IP over Avian Carriers with Quality of Service",
RFC 2549, April 1999.
[9] Narten, T., Nordmark, E. and W. Simpson, "Neighbor Discovery
for IP Version 6 (IPv6)", RFC 2461, December 1998.
[10] Draves, R. and R. Hinden, "Default Router Preferences,
More-Specific Routes, and Load Sharing", Internet Draft:
draft-ietf-ipv6-router-selection-02.txt, Work In Progress, June
2002.
[11] Savola, P., "Examining Site Multi-homing in Finnish Networks",
Master's Thesis. , April 2003.
[12] Draves, R., "Default Address Selection for Internet Protocol
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version 6 (IPv6)", RFC 3484, February 2003.
[13] David, D., Charles, C. and J. Jari, "Mobility Support in IPv6",
Internet Draft: draft-ietf-mobileip-ipv6-23.txt, Work In
Progress, May 2003.
Authors' Addresses
Julien Charbon
Keio university, Murai Lab, Louis Pasteur university and WIDE project
Keio University.
5322 Endo
Fujisawa-shi, Kanagawa 252-8520
Japan
Phone: +81-466-49-3529
Fax: +81-466-49-1101
EMail: julien@sfc.wide.ad.jp
URI: http://www.sfc.wide.ad.jp/~julien/
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
Koshiro Mitsuya
Keio university and WIDE project
Keio University.
5322 Endo
Fujisawa-shi, Kanagawa 252-8520
Japan
Phone: +81-466-49-3529
Fax: +81-466-49-1101
EMail: mitsuya@sfc.wide.ad.jp
URI: http://www.sfc.wide.ad.jp/~mitsuya/
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Thierry Ernst
Keio university and WIDE project
Keio University.
5322 Endo
Fujisawa-shi, Kanagawa 252-8520
Japan
Phone: +81-466-49-1395
Fax: +81-466-49-1100
EMail: julien@sfc.wide.ad.jp
URI: http://www.sfc.wide.ad.jp/~ernst/
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