1. Spring 2004 Network Mobility School of Electronics and Information Kyung Hee University Choong Seon HONG cshong@khu.ac.kr http://networking.khu.ac.kr

2. Spring 2004 2  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

3. Spring 2004 3 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  Background

4. Spring 2004 4  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

5. Spring 2004 5  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 AR MR AR MR Internet home link NEMO link visited link egress interface ingress interface

6. Spring 2004 6  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 LFH LFR MR VMH AR MHLMH AR

7. Spring 2004 7  Terminology: Nested Mobility AR Top-Level MR AR Internet MR root-NEMO child-NEMO NEMO AR VMR LMRMR TLMR child-NEMO LMR parent-NEMO leaf-NEMO

8. Spring 2004 8  Terminology: Multi-Homing AR Internet MR AR Domain 1 Domain 2

9. Spring 2004 9  NEMO & MANET  Different Problem MR AR Internet AR NEMO MANET MR  MANET  NEMO

10. Spring 2004 10  Usage Scenario PAN (Personal Area Network) Public Safety System Vehicular Network  Train, Car, Airplane

11. Spring 2004 11  PAN Office Airport Hotel

12. Spring 2004 12  Public Safety System MNNs MR MNNs MR MNNs MR MNNs

13. Spring 2004 13  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) Car NavigationCar Audio Speaker PDA GW Body network Control network Cellular PhoneWireless Lan Key DSRC : Dedicated Short Range Communications

14. Spring 2004 14  Requirement Migration Transparency (Permanent Connectivity) Performance Transparency (Seamless Mobility) Mobility Management Transparency for MNNs Scalability  Large NEMO  Large number of NEMO  Large number of CN Minimum Signaling Overload Routing Optimization Nested Mobility No impact on CNs or Internet routing Security  Confidentiality  Authentication  Authorization  Location Privacy  Access Control

15. Spring 2004 15  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

16. Spring 2004 16  Operation overview CN AR Internet AR MR LFNs HA Mobile Network

17. Spring 2004 17  Mobile N/W in Home N/W CN AR Internet AR MR LFNs HA Foreign N/W with Prefix C:: Home N/W Prefix A:: Mobile N/W Prefix B::

18. Spring 2004 18 CN AR Internet AR MR LFNs HA MR with HOA A::1 Home Prefix A::  Mobile N/W in Home N/W

19. Spring 2004 19 CN AR Internet AR MR LFNs HA Mobile N/W moves to Foreign N/W MR gets COA C::1 Prefix C::  Mobile N/W in Foreign N/W

20. Spring 2004 20  BU with Mobile N/W Prefix CN AR Internet AR MR LFNs HA MR sends HA BU which binds A::1 and C::1 and notifies Mobile N/W Prefix B:: HA replies BA HA changes its Binding Cache

21. Spring 2004 21 CN AR Internet AR MR LFNs HA Bi-directional tunnel is made between MR & HA  Bi-directional tunnel Set-Up

22. Spring 2004 22 CN AR Internet AR MR LFNs HA 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.  Advertising Mobile N/W Reachability

23. Spring 2004 23 CN AR Internet AR MR LFNs HA CN sends a packet to a LFN HA receives the packet. Route lookup on HA returns MR as the next hop  Forwarding Packets

24. Spring 2004 24 CN AR Internet AR MR LFNs HA With Binding Cache, HA sends encapsulated packet to MR. MR decapsulates the packet and forwards to the LFN.  Forwarding Packets

25. Spring 2004 25  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) BA  Status 140: Mobile Router Operation not permitted 141: Invalid Prefix 142: Not Authorized for Prefix 143: Mobile Network Prefix information unavailable Sequence # Mobility options LifetimeReservedAHLK R

26. Spring 2004 26  Message Formats Mobile Network Prefix Option in the BU  To indicate to the HA the prefix information for the mobile network TypeLength =18 ReservedPrefix Len(8bits) Mobile Network Prefix

27. Spring 2004 27  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

28. Spring 2004 28  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 one or more Mobile Network Prefix OptionsMR includes one or more Mobile Network Prefix Options in the BU

29. Spring 2004 29  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 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

30. Spring 2004 30  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

31. Spring 2004 31  Prefix Table HA MUST maintain this table if the Mobile Routers operate under the implicit mode  Entry in the prefix table Home Address of MRThe Home Address of MR –is used as the key for searching the pre-configured prefix table Mobile Network PrefixThe Mobile Network Prefix of the Mobile Router associated with the Home Address Home address of MRMobile Network Prefix of MR

32. Spring 2004 32  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

33. Spring 2004 33  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) By sending a BU with the lifetime set to zero  Mobile Network Prefix De-registration

34. Spring 2004 34  Forwarding Packets to forward a received data packet to MR  HA uses only the routing table, only the BC or combination S: HA_MR’s addr D: MR’s CoA S: CN’s addr D: MR or MNN S: HA_MR’s addr D: MR’s CoA S: CN’s addr D: MR or MNN Inner Outer Inner Outer HA_MR MR Bi-directional tunnel Example 1(combination)  HA: Example 2  HA: Next hop = MR’s Home Address MR’s HoA  MR’s CoA Outgoing interface= tunnel interface bt HA and MR

35. Spring 2004 35  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 S: MR’s CoA D: HA_MR’s addr S: MR’s link-local addr D: HA’s link-local addr S: HA_MR’s addr D: MR’s CoA S: HA’s link-local addr D: MR’s link-local addr Inner Outer Inner Outer HA_MR MR Bi-directional tunnel MR  (in home link) runs a routing protocol by sending routing updates through its egress interface HA  in routing entry Next hop : MR’s link-local addr

36. Spring 2004 36 CN AR Internet AR MR LFNs HA for MR HA for MH MH  Pinball Routing

37. Spring 2004 37  Pinball Routing CN AR Internet AR HA for MR HA for MH MH MR LFNs

38. Spring 2004 38  Pinball Routing CN AR Internet AR HA for MR HA for MH MR LFNs MH

39. Spring 2004 39  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

40. Spring 2004 40  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.