Transcript pinball hotel

Network Mobility
School of Electronics and Information
Kyung Hee University
Choong Seon HONG
[email protected]
http://networking.khu.ac.kr
Spring 2004
Contents
 Overview
 Terminology
 Usage Scenario
 Problem Scope & Requirements
 Basic Solution
 Operation overview
 Message Formats
•
•
•
Binding Update/ Binding Acknowledgement
Mobile Network Prefix Option
Mobile Router Operation
 Home Agent Operation
 Et Cetra
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Background
 Many IP devices will be mobile
 Moreover, many networks (LAN & PAN) will be mobile.
 in moving vehicles (cars, trains, planes, ships, etc)
 in moving bodies (humans, animals, equipment, etc)
 Permanently connected to the Internet
Internet
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What is a Mobile Network
 A Mobile Network is an entire network, moving
as a unit, which changes its point of
attachment to the Internet. A NEMO may be
composed by one or more IP-subnets
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Terminology
 MR MR one or more IP-subnets
 mobile as a unit
 connected to the Internet via 1 or more mobile routers
(MR)
 MR changes its point of attachment
Internet
AR
AR
visited link
MR
NEMO link
home link
egress interface MR
ingress interface
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Terminology: Mobile Network Nodes
 MNNs: any node attached a NEMO
 MR: Mobile Router
 LFN: Local Fixed Node
• LFR: ~ Router
• LFH: ~ Host
 LMN: Local Mobile Node
• LMR: ~ Router
• LMH: ~ Host
 VMN: Visiting Mobile Node
• VMR: ~ Router
• VMH: ~ Host
 CN: Correspondent Node
 any node corresponding with 1 or more
MNNs
CN
AR
MH
AR
AR
MR
LMH
LFR
LFH
VMH
LMH
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Terminology: Nested Mobility
AR
MR
Internet
AR
AR
MR
parent-NEMO
NEMO
root-NEMO
TLMR
Top-Level MR
LMR
child-NEMO
leaf-NEMO
VMR
child-NEMO
leaf-NEMO
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Terminology: Multi-Homing
Internet
Domain 1
AR
MR
AR
Domain 2
MR
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NEMO & MANET
 Different Problem
 MANET 
NEMO
Internet
AR
AR
MR
NEMO
MR
MANET
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Usage Scenario
 PAN (Personal Area Network)
 Public Safety System
 Vehicular Network
Train, Car, Airplane
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PAN
Office
Hotel
Airport
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Public Safety System
MNNs
MR
MNNs
MR
MR
MR
MR
MR
MNNs
MNNs
MNNs
MNNs
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Vehicular Network: InternetCar
 ~ 70 computers in a vehicle.
 3 subnetworks, in general.
 Multimedia network (for Car Audio, Navigation System)
 Body network (for Head light, Power Window)
 Control network (for Engine, Break)
 At first, Multimedia network will be using Internet Protocol.
 Multi-homing
 A vehicle has more than one communication devices
( cellular phone, DSRC (which is designed for automobile), PHS,
Wireless LAN, etc)
Cellular Phone
Key
PDA
Speaker
Wireless Lan
Car Navigation
Car Audio
GW
Body network
GW
Control network
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DSRC : Dedicated Short Range Communications
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Requirement




Migration Transparency (Permanent Connectivity)
Performance Transparency (Seamless Mobility)
Mobility Management Transparency for MNNs
Scalability





Minimum Signaling Overload
Routing Optimization
Nested Mobility
No impact on CNs or Internet routing
Security
 Large NEMO
 Large number of NEMO
 Large number of CN
 Confidentiality
 Authentication
 Authorization
 Location Privacy
 Access Control
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Basic Solution
 Nemo Basic Support Protocol
 draft-ietf-nemo-basic-support-02.txt
 NEMO solution requires setting up a bi-directional tunnel
between the MR and its HA
 All traffic between the nodes in the Mobile Network and CNs passes
through the HA
 Mobile Router
 Default gateway for the Mobile Network
 moving away from the home link and attaches to a new AR
 acquires a CoA from the visited link
 sends a BU(‘R’ bit) to its HA as a mobile router
 Home Agent
 successfully processes the BU and sets up forwarding for the
Mobile Network Prefix
 sends a BA to the MR
 establishes a bi-directional tunnel
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Operation overview
CN
AR
HA
Internet
MR
AR
LFNs
Mobile Network
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Mobile N/W in Home N/W
CN
AR
HA
Internet
Home N/W Prefix
A::
MR
AR
Mobile N/W Prefix
B::
LFNs
Foreign N/W
with Prefix
C::
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Mobile N/W in Home N/W
CN
AR
HA
Internet
Home Prefix
A::
MR MR with HOA A::1
AR
LFNs
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Mobile N/W in Foreign N/W
CN
AR
HA
Internet
AR
Prefix
C::
Mobile N/W moves to
Foreign N/W
MR gets COA
C::1
MR
LFNs
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BU with Mobile N/W Prefix
CN
AR
HA
Internet
AR
HA replies
BA
HA changes its Binding Cache
MR sends HA
BU
which binds
A::1 and C::1
and notifies
Mobile N/W
Prefix B::
MR
LFNs
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Bi-directional tunnel Set-Up
CN
AR
HA
Internet
AR
MR
Bi-directional tunnel
is made
between MR & HA
LFNs
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Advertising Mobile N/W Reachability
CN
AR
HA
Internet
AR
MR
HA updates its Routing Table
according to
Mobile N/W Prefixes from MR
The Next Hop of
MNNs is MR.
HA propagates this
Routing Information.
LFNs
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Forwarding Packets
CN sends a packet
to a LFN
CN
AR
HA
Internet
HA receives
the packet.
AR
MR
Route lookup on
HA returns MR
as the next hop
LFNs
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Forwarding Packets
CN
AR
HA
Internet
AR
MR decapsulates
the packet and
forwards to the
LFN.
With Binding
Cache, HA sends
encapsulated
packet to MR.
MR
LFNs
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Message Formats
 BU
 Mobile Router flag (R)
• 1: BU from the MR
• 0: BU from the MN
– SHOULD not forward packets destined for the mobile network to
the MR
 Mobility Options (MNP option, MNP Length option)
Sequence #
A H L K R
Reserved
Lifetime
Mobility options
 BA
 Status
•
•
•
•
140: Mobile Router Operation not permitted
141: Invalid Prefix
142: Not Authorized for Prefix
143: Mobile Network Prefix information unavailable
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Message Formats
 Mobile Network Prefix Option in the BU
 To indicate to the HA the prefix information for the mobile network
Type
Length=18
Reserved
Prefix Len(8bits)
Mobile Network Prefix
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MR operation
 Exchanges specific binding message with HA
 Uses various data structures
 Joins certain multicast groups
Joins multicast group at Home N/W
NOT joins multicast group at Foreign N/W
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Sending Binding Update
 MR MUST sets the ‘R’ bit to 1 & also set the ‘H’ bit
 Three modes
Implicit
• not include any options in BU
• HA can determine the Mobile Network Prefix owned the
mobile router (e.g. pre-configured prefix table)
Explicit
• MR includes one or more Mobile Network Prefix Options in
the BU
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Data structure/ Prefix information field
 Like a MN, a MR maintains a Binding update list
 Prefix information field
• is used to store any prefix information
• MR sets the ‘R’ bit in the BU and not include any prefix info
– (in implicit mode) set to null
<Binding Update list structure>
Dest. IP addr.
Max. of seq#
Home addr.
Time at which BU was last sent to this dest.
- used in rate limiting restriction
CoA - to determine if BU was
sent after handoff
Rtx. state for BU
Initial value of lifetime in BU
A flag - whether or not future BU should be
sent to this dest.
Remaining lifetime of binding
Prefix information
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HA operation
 Uses various data structures
 Mobile Network Prefix Registration
 Advertising Mobile Network Reachability
Injects routes for Mobile Network into Internet
 Establishment of Bi-directional Tunnel
 Forwarding Packets
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Prefix Table
 HA MUST maintain this table if the
Mobile Routers operate under the implicit
mode
Entry in the prefix table
• The Home Address of MR
– is used as the key for searching the pre-configured prefix
table
• The Mobile Network Prefix of the Mobile Router
associated with the Home Address
Home address of MR
Mobile Network Prefix of MR
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Mobile Network Prefix Registration
 HA’s check list
 BU MUST be authenticated by IPsec
 Home Registration (H) bit MUST be set
 MNP Length opt. is present, only one instance of this
opt.
 Check list OK!  retrieves the Mobile
Network Prefix information
Mobile Network Prefix Length Option
• Home Address & Mobile Network Prefix Length
Mobile Network Prefix Option
• Mobile Network Prefix field and the Prefix Length
field
No Option
• Find the MNP in pre-configured prefix table
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Sending BA





‘0’(BU accepted)
‘140’(Mobile Router Operation not permitted)
‘141’(Invalid Prefix)
‘142’(Not Authorized for Prefix)
‘143’(Mobile Network Prefix information unavailable)
Mobile Network Prefix De-registration
 By sending a BU with the lifetime set to zero
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Forwarding Packets
 to forward a received data packet to MR
 HA uses only the routing table, only the BC or combination
 Example 1(combination)
<Example 1>
Outer Inner
 HA:
<in Routing Table>
Next hop = MR’s Home Address
<in BCE>
MR’s HoA  MR’s CoA
D: MR’s CoA
S: CN’s addr
D: MR or MNN
Bi-directional tunnel
 Example 2
Outgoing interface=
tunnel interface bt HA and MR
Outer Inner
HA_MR
 HA:
S: HA_MR’s addr
S: HA_MR’s addr
MR
D: MR’s CoA
S: CN’s addr
D: MR or MNN
<Example 2>
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Support for Dynamic routing protocol
 HA and MR run a intra-domain routing protocol like RIPng and
OSPF through the bi-directional tunnel
 Advantages:
 useful when mobile network is large with multiple subnets
 routing changes are propagated very quickly
Outer Inner
 MR
 (in home link) runs a routing
protocol by sending routing
updates through its egress
interface
 HA
 in routing entry
D: HA_MR’s addr
S: MR’s link-local addr
D: HA’s link-local addr
Bi-directional tunnel
HA_MR
Outer Inner
Next hop : MR’s link-local addr
S: MR’s CoA
MR
S: HA_MR’s addr
D: MR’s CoA
S: HA’s link-local addr
D: MR’s link-local addr
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Pinball Routing
CN
AR
HA for MR
Internet
MR
HA for MH
AR
LFNs
MH
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Pinball Routing
CN
AR
HA for MR
Internet
HA for MH
AR
MR
MH
LFNs
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Pinball Routing
CN
AR
HA for MR
Internet
HA for MH
AR
MR
LFNs
MH
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Next Step/ Route Optimization
 Candidate Solutions
IPv6 Reverse Routing Header and its
application to Mobile Networks
• draft-thubert-nemo-reverse-routing-header-04
ND-Proxy based Route Optimization for
Mobile Nodes in Mobile Network
• draft-jeong-nemo-ro-ndproxy-02.txt
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Current NEMO Internet Drafts
 "Network Mobility Support Goals and
Requirements", Thierry Ernst, 18-Feb-04
 "Network Mobility Support Terminology",
Thierry Ernst, Hong Lach, 18-Feb-04
 "Nemo Basic Support Protocol", Vijay
Devarapalli, 23-Dec-03.
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