Transcript Ad hoc 환경에서의 IPv6 적용 기술 정재훈 PEC, ETRI [email protected] Contents      Introduction Ad-hoc Routing Protocols Autoconfiguration Technology for IPv6 MANET Global Connectivity for IPv6 MANET Conclusion.

Ad hoc 환경에서의 IPv6 적용 기술
정재훈
PEC, ETRI
[email protected]
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Contents



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
Introduction
Ad-hoc Routing Protocols
Autoconfiguration Technology for IPv6 MANET
Global Connectivity for IPv6 MANET
Conclusion
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Introduction (1/2)

Categories of Wireless Networks

Infrastructured Networks


Infrastructureless Networks


Cellular Networks, Wireless LAN (WLAN)
Ad-hoc Networks
Ad-hoc Networks
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유선 기반 망 (Infrastrured Networks) 없이 무선 이동단말로만 구
성된 망
Multi-hop Routing을 위해 각 이동단말이 Router 역할을 수행함
용도

긴급구조, 전쟁, 홈 네트워크, Shopping Mall, 임시 공동작업,
도로에서의 차량 간의 통신, 공항에서의 티켓팅, 사무실 등.
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Infrastructured N/W vs. Infrastructureless N/W
Internet
WLAN
Cellular
Mobile Ad-hoc Networks
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Introduction (2/2)
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MANET에서의 이슈
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
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Ad-hoc Unicast Routing
Ad-hoc Multicast/Broadcast Routing
Power Saving
Automatic Support of Networking Facility in MANET


Autoconfiguration Technology
Global Connectivity for MANET
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Ad-hoc Routing Protocols
Ad-hoc Unicast Routing Protocols
 IPv6 Ad-hoc Routing Protocols

IPv6 AODV
 IPv6 MAODV

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Ad-hoc Unicast Routing Protocols
Ad-hoc routing protocols
Source-initiated
Demand-driven
Table-driven
DSDV
CGSR
WRP
AODV
DSR
LMR
ABR
TORA
SSR
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Table-driven Routing Protocols
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Characteristics
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Maintenance of consistent, up-to-date routing information
from each node to every other node in the network
Each node
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
Criterion of Classification of Routing Protocols
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maintains one or more tables to store routing information
propagates updates of network topology
Number of necessary routing-related tables
Methods by which changes in network structure are broadcast
Examples
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DSDV, CGSR, WRP, TBRPF, OLSR
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Demand-driven Routing Protocols
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Characteristics
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Creation of routes only when desired by the source node
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Route Discovery Process is completed


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Until the destination becomes inaccessible along every path
from the source
Until the route is no longer desired
Criterion of Classification of Routing Protocols
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
Once a route is found
When all possible route permutations have been examined
Maintenance of a Route


By Route Discovery Process
Method by which route finding is performed
Examples
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AODV, DSR, LMR, TORA, ABR, SSR
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IPv6 Ad-hoc Routing Protocols
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IPv6 Ad-hoc Unicast Routing Protocol
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AODV (Ad-hoc On-demand Distance Vector) Routing Protocol
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AODV has been already implemented by some organizations
including NIST.
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AODVv6 which is IPv6 AODV has been being implemented by
ETRI & ICU.
Linux Kernel Version: 2.4
IPv6 Ad-hoc Multicast Routing Protocol
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MAODV (Multicast AODV) Routing Protocol
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MAODV works very similarly to PIM-DM.
MAODVv6 which is IPv6 MAODV has been being implemented by
ETRI & ICU.
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AODV (1/3)
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AODV is improved DSDV algorithm
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
AODV minimizes the number of required broadcasts by
creating routes on a demand basis.
AODV doesn’t maintain a complete list of routes as in
DSDV algorithm.
 Nodes that are not on a selected path don’t maintain
routing information or participate in routing table
exchanges
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AODV (2/3)

Path Discovery process



When source node doesn’t already have a valid route to that
destination, it initiates a path discovery process to locate the
other node.
Path Discovery
 broadcasts a route request (RREQ) packet to its neighbors.
 Neighbors forward the request to their neighbors, and so on
until either the destination or an intermediate node
with a “fresh enough” route to the destination is located.
Loop-free

AODV utilizes destination sequence numbers to ensure all
routes are loop-free
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AODV (3/3)
a) Propagation of the RREQ
b) Path of the RREP to the source
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Autoconfiguration Technology
for IPv6 MANET
Autoconfiguration Technology?
 Autoconfiguration Technology for IPv6 MANET

Unicast Address Autoconfiguration
 Multicast Address Autoconfiguration
 Multicast Name Resolution
 Service Discovery

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Autoconfiguration Technology?

What is Autoconfiguration?
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
Why is Autoconfiguration needed?
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The technology that let IP-enabled devices be able to
communicate one another in infrastructureless environment.
To provide hosts with the automatic configuration related to
networking.
To let it possible for hosts communicate when either dynamic or
static configuration is impossible.
To provide the quick and easy configuration related to the network
facility in MANET environment.|
Issues of IETF Zeroconf Working Group




Unicast Address Autoconfiguration
Multicast Address Allocation
Name Resolution (DNS)
Service Discovery
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Autoconfiguration Technology for IPv6 MANET
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Unicast Address Autoconfiguration
 Automatic configuration of a unique IP address within the scope in
which the address will be used.

Multicast Address Autoconfiguration
 Allocation of a unique multicast address for the application which
needs a new multicast address.

Multicast Name Resolution
 Translation between name and
IPv6 address

Service Discovery
 Discovery of the necessary service
on the network without prior
configuration.
Autoconfiguration
Technology
in IPv6-based MANET
Multicast Address Autoconfiguration
Multicast Name Resolution
Service Discovery
Unicast Address Autoconfiguration
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Autoconfiguration for IPv6 MANET

Network Configuration

Protocol Stack of Mobile Node
Application
Multicast Name
Ad-hoc
Ad-hoc
Resolution
Unicast Routing Multicast Routing
B
A
C
D
E
TCP / UDP
IPv6
Mobile Node
Unicast Address
Autoconfiguration
Multicast Address
Autoconfiguration
Wireless Link
NIC
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Unicast Address Autoconfiguration (1/2)
: Extended DAD Procedure in MANET
1st Try of Host A
 MAC Address - a9:bb:cc:dd:ee:ff
 IPv6 Address - fec0:0:0:ffff:abbb:ccff:fedd:eeff
MAC & IPv6 Address of Host C
 MAC Address – a9:bb:cc:dd:ee:ff
 IPv6 Address - fec0:0:0:ffff:abbb:ccff:fedd:eeff
MANET Prefix
EUI-64
The address of Host A conflicts with that of Host C.
Host C sends NA message to Host A.
2nd Try of Host A
 64-bit Random Number – 1111:2222:3333:4444
 IPv6 Address - fec0:0:0:ffff:1111:2222:3333:4444
Random Number
The address of Host A doesn’t conflict with that of any other host.
This address can be used as the unicast address of Host A.
Host B
Host A
NS message
Host C
NA message
Router
Wireless Link
Where NS : Neighbor Solicitation,
NA : Neighbor Advertisement
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Unicast Address Autoconfiguration (2/2)
: Procedure of Unicast Address Configuration
Generation of Lower 64 bits in EUI-64
Generation of Temporary address with
MANET_INIT_PREFIX and Lower 64 bits
MANET_INIT_PREFIX
 fec0:0:0:fffe::/64
Generation of Tentative address with
MANET_PREFIX and Lower 64 bits
MANET_PREFIX
fec0:0:0:ffff::/64
Transmission of Extended NS message
Was any extended
NA message received
from other node?
YES
Generation of 64-bit
Random Number
NO
Configuration of
Unicast address in NIC
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Multicast Address Autoconfiguration

(a)
Format of Site-local Unicast Address (a) and
Format of Site-local Multicast Address (b)
16-bit
64-bit
Network Prefix
Subnet
ID
Interface ID
(b)
ff
16
64
Subnet
ID
Interface ID
Procedure of Multicast Address
Allocation
Request of
Multicast Address Allocation
48-bit
8 4,4

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Generation of Unused Group ID
Group ID
Generation of a multicast address
Flags
P=1, T=1
Scope
5
Random
Number
Delivery of the multicast address
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Service of Multicast Application
B
A
C
D

E
Multicast Service Scenario
1. Unicast Address Autoconfiguration
Unicast Address
Autoconfiguration
- Booting of each Mobile Node (MN)
- Unicast address configuration in NIC
2. Multicast Address Autoconfiguration
A
B
1
C
1
D
1
E
1
- Run of Video-conferencing Tool
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& Creation of a new Session
- Allocation of a multicast address
2
3
4
6
5
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Multicast Address
Autoconfiguration
3. Advertisement of Sesstion information
4. Join to the new Session in MN A
5. Join to the new Session in MN E
6. Transmission of Video/Audio data
by MN A
7. Transmission of Video/Audio data
by MN E
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Multicast Name Resolution
Multicast Name Resolution (MNR) is performed by
mDNS (Multicast DNS)
Procedure of the resolution
from domain name to IPv6 address in MNR

Sender
Responder
MNR query (What is IPv6 address of “host.private.local.”?)
via site-local multicast over UDP
1
2
MNR response (IPv6 address of “host.private.local.”)
via unicast over UDP
3 Verification of MNR response
- Does the value of the response conform to
the addressing requirements?
4 If the result is valid,
then the Sender caches and uses the response.
else the Sender ignores the response and continues
to wait for other responses.
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Service Discovery
Service Discovery can be performed by MNR &
DNS SRV Resource Record

Simple Zone File containing DNS SRV resource records
for service discovery
$TTL 3600
;; Name to Address Lookups
localhost.private.local. IN AAAA ::1
; Localhost with Loopback Address
host.private.local. IN AAAA fec0:0:0:ffff::202:2dff:fe1b:e851
; MN’s Domain Name with Site-Local Address
;; DNS SRV Resource Records
_multimedia1._tcp.private.local. 4000 IN SRV 0 1 3000 host.private.local.
_multimedia2._udp.private.local. 4000 IN SRV 0 1 3001 host.private.local.
_service-name._protocol.domain-name TTL Class SRV Priority Weight Port Target
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Global Connectivity for IPv6 MANET
Internet Connectivity for IPv6 MANET
 Internet Gateway Discovery
 Network Mobility (NEMO)

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Internet Connectivity for IPv6 MANET

Why do we need to support the Internet
connectivity in MANET?
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When mobile nodes in MANET want to communicate
with hosts in the global Internet
IETF NEMO BoF has started to study the support the
network mobility.
What is needed to support the global
connectivity?

Internet Gateway Discovery

It informs the mobile nodes of the address of the gateway
that connects MANET to the Internet.
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Internet Gateway Discovery (1/2)
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Two ways to do Internet Gateway Discovery
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Extended Route Discovery
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Extended NDP (Neighbor Discovery Protocol)
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Sending RREQ (Route Request) for global prefix information &
Getting RREP (Route Reply)
We need to extend RREQ / RREP of IPv6 AODV.
Sending MANET Route Solicitation (RS) &
Getting MANET Router Advertisement (RA)
We need to extend NDP.
A node uses an arbitrary address for the discovery


Home Address
Site-local address by Unicast Address Autoconfiguration
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Internet Gateway Discovery
by Extended Route Discovery
Internet
MANET
GW
RREP
RREQ
B
RREQ
RREQ
RREP
A
Routing Table
default: GW
C
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Internet Gateway Discovery
by Extended NDP
Internet
MANET
GW
RA
RS
B
RS
RS
RA
A
Routing Table
default: GW
Global Unicast Address
Autoconfiguration
C
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Network Mobility (NEMO)

We need to support the Network Mobility


정의: 단말 간의 통신과 인터넷으로의 연동 지원
응용 분야

PAN (Personal Area Network)
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
Public Safety System
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
재해복구 임시망
Vehicular Network


개인 휴대기기 이동망
항공기, 버스, 자동차, 지하철 망 등.
What is MONET?


정의: MONET(Mobile Network)는 인터넷 연동을 위해
이동 라우터 (Mobile Router)를 포함한 하나 이상의 서브넷으로
구성된 망.
IETF NEMO BoF에서 연구되고 있음.
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NEMO Network
Internet
WLAN
Cellular
PAN
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Internet Car
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약 70개의 정보단말이 내장
3개의 서브넷으로 구성
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Multimedia network
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Car audio, Navigation system, etc.
Body network
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Head light, Power window, etc.
Control network

Engine, Break, etc.
Multi-homing 제공

외부망과의 연동을 제공하기 위해 하나 이상의 Communication Device를 포함함.

Cellular phone, WLAN, DSRC, PHS, etc.
Mobile Routers
Cellular
Phone
Key
PDA
Speaker
WLAN
Navigation
ITS
Audio
GW
Body network
GW
Control network
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Conclusion

Ad-hoc에서의 라우팅, 서비스, 인터넷 연동에 있
어서 IPv6는 IPv4 보다 유리함.




주소 자동 설정, 멀티캐스트 주소 할당, DNS 서비스, 서
비스 탐색 등.
Mobile IPv6를 이용한 네트워크 이동성 제공
IPv6로 누구나 쉽게 시간과 장소에 관계없이 통신 서비
스를 제공 받을 수 있음.
Ad-hoc에서의 보안

유선망과 WLAN 같은 무선망보다 네트워크 보안 제공
이 어렵다.

라우팅, 서비스 등의 Security 기능이 다른 네트워크 보다 더욱
필요함.
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References
[1] Elizabeth M. Royer and Chai-Keong Toh, “A Review of Current Routing Protocols for Ad Hoc Mobile
Wireless Networks”, IEEE Personal Communications, April 1999.
[2] Charles E. Perkins, Elizabeth M. Belding-Royer and Samir R. Das, “Ad hoc On-Demand Distance Vector
(AODV) Routing”, (work in progress) draft-ietf-manet-aodv-10.txt, January 2002.
[3] Elizabeth M. Royer and Charles E. Perkins, “Multicast Ad hoc On-Demand Distance Vector (MAODV)
Routing”, draft-ietf-manet-maodv-00.txt, July 2000.
[4] Erik Guttman, "Autoconfiguration for IP Networking:Enabling Local Communication", IEEE Internet
Computing, May/June 2001.
[5] Jaehoon Jeong and Jungsoo Park, “Autoconfiguration Technologies for IPv6 Multicast Service in Mobile Adhoc Networks”, 10th IEEE International Conference on Networks, Aug. 2002.
[6] Jung-Soo Park and Myung-Ki Shin, “Link Scoped IPv6 Multicast Addresses”, (work in progress) draft-ietfipv6-link-scoped-mcast-02.txt, July 2002.
[7] Levon Esibov, Bernard Aboba and Dave Thaler, “Linklocal Multicast Name Resolution (LLMNR)”, draftietf-dnsext-mdns-11.txt, July 2002.
[8] A. Gulbrandsen, P. Vixie and L. Esibov, “A DNS RR for specifying the location of services (DNS SRV)”,
RFC2782, Feb. 2000.
[9] Ryuji Wakikawa, et al., “Global connectivity for IPv6 Mobile Ad Hoc Networks”, draft-wakikawa-manetglobalv6-01.txt, July 2002.
[10] Thierry Ernst and Hong-Yon Lach, “Network Mobility Support Terminology”, draft-ernst-monetterminology-01.txt, July 2002.
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