1. 2002 IPv6 技術巡迴研討會 IPv6 Mobility

2. Agenda Mobile IP Overview Mobile IPv4 IPv6 and Mobile IPv6
Current status of MIPv4 and MIPv6
Mobile IP in GPRS, 3GPP and 3GPP2
Mobile IP and WLAN

3. What is Mobile IP ? C. Perkins, “IP Mobility Support”, RFC 2002
Each mobile node is always identified by its home address, regardless of its current point of attachment to the Internet
protocol enhancements that allow transparent routing of IP datagrams to mobile nodes in the Internet

4. Why we need Mobile IP ?
Change point of attachment & identified by its home address
I want to access Internet. I need an IP address
OK, I can offer you DHCP (dynamic host configuration protocol) + NAT (network address translator)
No, some special applications such as SIP(Session Initiation Protocol) and NAT are conflict. I need a global unique IP address
OK, I can give you DHCP without NAT
I need a permanent IP address
Why ? ….

5. Why we need Mobile IP ? (Cont.)
If you really need to change your point of attachment but don’t want to change your IP address, why IP is not enough ?
IP is based on network-prefix routing
Protocol enhancements
Mobile IP defines protocol enhancement to support IP mobility

6. Why we need Mobile IP ? (Cont.)
Why do you need to change your point of attachment and also require a permanent IP ?
Your devices become mobile
You want to be reached by your IP even you are not in your home network
Your notebook, PDA, and mobile phone become more and more powerful
You want to be a server
You want to build up an end-to-end secure connection in IP layer

7. Summary Mobile IP is an enhancement based on Internet Protocol (IP)
Mobile IP is needed in case you need to to change your point of attachment and also require a permanent IP address
More and more devices become wireless and mobile (based on different (radio) access technologies)
More and more devices are IP-enable and IP-addressable
Different (radio) access technologies are co-existing and share the same IP backbone
More and more devices request a permanent IP address
More and more service need customers to have a permanent IP address
L2 mobility is managed by L2 technologies and Mobile IP handles IP mobility (L3 mobility)

8. Host D IP:140.96.102.49 Subnet Mask : 255.255.255.0 Router B Host C
Port D:
Port C :
Host D
IP:
Subnet Mask :
Router B
Host C
IP:
Subnet Mask :
Port A:
Port B :
Host A
IP:
Subnet Mask :
Router A
Host B
IP:
Subnet Mask :

9. Host D IP:140.96.102.49 Subnet Mask : 255.255.255.0 Router B Host C
Port D:
Port C :
Host D
IP:
Subnet Mask :
Router B
Host C
IP:
Subnet Mask :
Port A:
Port B :
Host A
IP:
Subnet Mask :
Router A
Host B
IP:
Subnet Mask :

10. IP Routing (Cont.) Host D IP:140.96.102.49 Subnet Mask : 255.255.255.0
Port D:
Port C :
Host D
IP:
Subnet Mask :
Router B
Host C
IP:
Subnet Mask :
Port A:
Port B :
Host A
IP:
Subnet Mask :
Router A
Host B
IP:
Subnet Mask :

11. Mobile IP Operations
Overall Architecture

12. Mobile IP Operations (Cont.)
A basic scenario
A MN is in its home network
It moves to a visit network
Somebody, say CN, wants to make a connection with the MN by using its home IP address

13. Mobile IP Operations (Cont.)
Step 1 :
Agent advertisement
Sent by HA
Let MN know HA’s IP MN
Store HA’s IP

14. Mobile IP Operations (Cont.)
Step 2 :
MN moves to a visit network

15. Mobile IP Operations (Cont.)
Step 3 :
Agent advertisement
Sent by FA
Let MN know it moves to a foreign network
Let MN know its new CoA MN
Stores CoA

16. Mobile IP Operations (Cont.)
Step 4 : MN
Sends registration request to FA
Get registration reply from FA FA
Relay Reg-Req to HA
HA reply Reg-Reply to FA

17. Mobile IP Operations (Cont.)
Step 3’ :
MN does not get agent advertisement or
FA registration is not required MN
Got CoA from DHCP

18. Mobile IP Operations (Cont.)
Step 4’ : MN
Sends registration request to HA
Get registration reply from HA

19. Mobile IP Operations (Cont.)
Step 5: HA
Sends reply ARP (proxy ARP) for MN

20. Mobile IP Operations (Cont.)
Step 6: CN
Initiates a connection
Router
Sends packets to MN IP but with HA’s MAC

21. Mobile IP Operations (Cont.)
Step 7: HA
Encapsulate the packets (IP in IP)
Tunnels the packets to FA FA
Decapsulate the packets
Forward packets to MN

22. Mobile IP Operations (Cont.)
Step 8: MN
Reply packets to CN through router or
Reply packets to CN through FA

23. Mobile IP Operations (Cont.)
Step 8’: MN
Sends packets to FA FA
tunnels packet and sends to HA HA
Decapsulate packets
Forward to CN

24. Mobile IP Operations (Cont.)
Step 9: MN
Moves back to home network
Deregistration its CoAs

25. Mobile IP Operations (Cont.)
In detail
(FA/HA) Agent Discovery
Registration procedures
Packet tunneling

26. Mobile IP Operations (Cont.)
Agent Advertisement
Tell MN its location
Notify MN with CoA
Agent Solicitation
Ask agent info

27. Route optimization & Smooth Handoff
Triangle Routing

28. Route optimization & Smooth Handoff (Cont.)
Binding cache

29. Route optimization & Smooth Handoff (Cont.)
Situation 1
Response to a Binding Request message

30. Route optimization & Smooth Handoff (Cont.)
Situation 2
Response to a Binding Warning message

31. Route optimization & Smooth Handoff (Cont.)
Situation 3
Reception of a packet destined
for a mobile node

32. Route optimization & Smooth Handoff (Cont.)
Smooth/fast/seamless handover
Smooth handover  low loss
Fast handover  low delay
30 ms?
Seamless handover  smooth and fast

33. Route optimization & Smooth Handoff (Cont.)
Packet lost

34. Route optimization & Smooth Handoff (Cont.)
MN notifies its previous FA
FA maintain MN’s binding cache
Registration req. extension

35. Route optimization & Smooth Handoff (Cont.)
Packet retunnel

36. Security Issues (Cont.)

37. Comparisons of Mobile IPv4 and Mobile IPv6

38. Mobile IPv6 Operations
Overall Architecture

39. Mobile IPv6 Operations (Cont.)
Step 1 :
Router advertisement
Sent by router
Let MN know its location
Tell MN HA’s IP MN
Store HA’s IP

40. Mobile IPv6 Operations (Cont.)
Step 2 :
MN moves to a visit network

41. Mobile IPv6 Operations (Cont.)
Step 3 :
Router
Router advertisement MN
Obtain stateless address by
Auto-configuration
Stores CCoA

42. Mobile IPv6 Operations (Cont.)
Step 3’ : MN
Got stateful CCoA from DHCPv6

43. Mobile IPv6 Operations (Cont.)
Step 4 : MN
Sends Binding Update to HA
Get Binding Acknowledge from HA

44. Mobile IPv6 Operations (Cont.)
Step 5: HA
Sends reply ARP (proxy ARP) for MN

45. Mobile IPv6 Operations (Cont.)
Step 6: CN
Initiates a connection
Router
Sends packets to MN IP
but with HA’s MAC

46. Mobile IPv6 Operations (Cont.)
Step 7: HA
Encapsulate the packets (IP in IP)
Tunnels the packets to MN

47. Mobile IPv6 Operations (Cont.)
Step 8: MN
Reply packets to CN through router or
Piggyback Binding Update

48. Mobile IPv6 Operations (Cont.)
Step 9: MN
Moves back to home network
Receive Router Advertisement
Send BU to HA and CN

49. Mobile IPv6 Operations (Cont.)
Step 10
Smooth handover
Send BU to HA in previous network
Use more than one CoA at the same time
Receive packets from all CoAs
Packets may send to
Home IP, previous CoA, and current CoA

50. Mobile IP current development
Hierarchical mobility management
Mobile IPv4 Regional Registration MN HA
FA 1
Network C
Network A
Network B
FA 2 CN

51. Hierarchical mobility management
Mobile IPv4 Regional Registration MN HA
FA 1
Network C
Network A
Network B
FA 2 CN MN

52. Hierarchical mobility management
Mobile IPv4 Regional Registration
Reduce number of signaling message to HA
Reduce delay when MN moves from one FA to another FA in the same visited network MN HA
FA 1
Network C
GFA
Network A
Network B
FA 2 CN

53. Hierarchical mobility management
Mobile IPv4 Regional Registration
Step 1 : registration at the GFA and the home agent
Network A
Network B
Network C CN MN HA
FA 1
FA 2
GFA
Local CoA 1
GFA address
Authentication Key

54. Hierarchical mobility management
Mobile IPv4 Regional Registration
Step 2 : moves to another FA and receives Local FA advertisement MN HA
FA 1
Network C
GFA
Network A
Network B
FA 2 CN MN

55. Hierarchical mobility management
Mobile IPv4 Regional Registration
Step 3 : regional registration at the GFA HA
FA 1
Network C
GFA
Network A
Network B
FA 2 CN MN

56. Hierarchical mobility management
Hierarchical MIPv6 mobility management MN HA
AR1/MAP
MAP
Network C
AR1/MAP
Network A
Network B CN
AR : access router
MAP : mobile anchor point

57. Mobile IP current development (Cont.)
Low latency handoffs
Why ?
Latency involved in handoff can be above the threshold required for the support of delay-sensitive or real-time services
Reduce the handoff latency
By help of L2 trigger message

58. Low latency handoffs
Low latency mobile IPv4 Handoffs
architecture

59. Low latency handoffs (Cont.)
PRE-REGISTRATION handoff protocol

60. Low latency handoffs (Cont.)
PRE-REGISTRATION handoff protocol-Timing Diagram (Network Initiated, Source Trigger)

61. Low latency handoffs (Cont.)
PRE-REGISTRATION handoff protocol-Timing Diagram (Network Initiated, Target Trigger)

62. Low latency handoffs (Cont.)
PRE-REGISTRATION handoff protocol-Timing Diagram (Mobile Initiated)

63. Low latency handoffs (Cont.)
POST-REGISTRATION handoff protocol

64. Low latency handoffs (Cont.)
POST-REGISTRATION handoff protocol – two party handoff

65. Low latency handoffs (Cont.)
POST-REGISTRATION handoff protocol – two party handoff timing diagram (source trigger)

66. Mobile IP and WLAN Portability Wireless Mobility Ubiquity
Change of network attachment point
Wireless
Wire-less
Mobility
You can move
Ubiquity
Utilize heterogeneous wired/wireless network freely
Wireless  Mobile  Mobile Wireless

67. Mobile IP and WLAN (Cont.)
cover L1/L2 technologies
Only provide wireless feature
Do not have mobility management functionality
Where is its L3 ?

68. Mobile IP and WLAN (Cont.)
WLAN L3 solution
Datacom
Session management
IP based
Mobility management
Mobile IP
AAA
Telecom
GPRS SM
GPRS GMM
HLR/SS7

69. Mobile IP and WLAN (Cont.)
More applications/software/features will be implemented over WLAN AP (that is what differentiate products)
Mobile IP
VPN
NAT
AAA
IPSec …

70. Mobile IP and WLAN (Cont.)
Is any problem with Mobile IP over WLAN ?
Fine for data/no real-time application
Problems with VPN
AAA
Problems with voice/real-time application
Handover delay
Solutions
Low latency mobile IP (work in progress in IETF, but development in progress in vendor)
AAA and mobile IP (work in progress in IETF, but development in progress in vendor)