Fast Handover in Mobile IPv4 and IPv6

Transcription

1 Fast Handover in Mobile IPv4 and IPv6 Raoul Schmidiger & Gregor Zographos April 28, 2005 Seminar: Mobile Systems Talk No.4

2 Content IPv4 (Gregor) IPv6 (Raoul) Problems in IP mobility (Gregor) Standards in Mobile IP (Gregor) Mobile IP (Gregor) Fast Handover in Mobile IPv4 (Gregor) Fast Handover in Mobile IPv6 (Raoul) Summary (Raoul) Discussion (Gregor & Raoul)

3 IPv4 From Jon Postel in RFC791 anno th Version of the Internet Protocol (IP) 32-Bit addresses length 24-Bit for the network part 8-Bit for the host part (ifi IP) IP-Packet (1500 Bytes) Header (Informations about source, goals, status, fragments etc.) Payload (includes transporting datas)

4 IPv4 Make no differences between Hosts/Routers IANA diversify the IP-adresses worldwide In several classes, reserved for special purposes (broadcast, multicast etc.) definite addresses possible Future

5 IPv6 IPv6 aka Next Generation Internet Protocol (IPng) Introduced by Internet Engineering Task Force (IETF) in 1994 (RFC 1752) Designed to run well in high performance networks as well as low bandwith networks (e.g. wireless) Existing internet devices can be upgraded to IPv6 through software installation Interoperable with IPv4 a must if introduction of IPv6 is to be successful Introduces new internet functionality

6 Why IPv6? Growth of interconnected computers so far was exponential The next phase of growth will probably not be driven by the computer market, but in markets that are extremely large - current generation of cellular phones, pagers, and personal digital assistants (Nomadic personal computing devices) - On demand TV etc. - Device control Additional needs next to an internet protocol are: - low overhead - autoconfiguration - mobility - built-in authentification and confidentiality

7 Changes from IPv4 to IPv6 Expanded Routing and Addressing Capabilities (adress size now 128 bits) "anycast address" Header Format Simplification Improved Support for Options Quality-of-Service Capabilities Authentication and Privacy Capabilities

8 IPv6 Adress (1) Unicast, anycast, multicast Adress space now slightly bigga: But practically only 8x10^17 to 2x10^33 will be used. Internet adress in HEX: IPv4 Adress will be stored in the low-order 32-bits to allow the gradual transition from IPv4

9 IPv6 Adress (2) Routing included in Adress: - Provider Selection (based on policy, performance, cost, etc.) - Host Mobility (route to current location) - Auto-Readdressing (route to new address) Adress contains source and destination AND optionally intermediate Nodes such as providers etc. a) Request: H1,H2 Response: H2,H1 b) Request: H1,P1,P2,P3,H2 Response: H2,P3,P2,P1,H1 c) 2 build in types of security: - IPng Authentication Header - IPng Encapsulating Security Header

10 Problems in IP mobility Definite address for each internet user Changing cell - changing address? What about packet-sending during the change of a cell? The solution of Internet Protocol mobility are Mobile IP!

11 Standards in Mobile IP Transparency Mobile End-system keeps the IP-address during network-change Resumption of communication after the network-change Compatibility No changes in Layer-2-Protocolls No changes on Router and fixnet systems Communication between mobile and fixnet systems

12 Standards in Mobile IP Security Authentify of registry messages guarantee of the privacy Efficiency As few as possible extra datas to the end-system

13 Mobile IP

14 Mobile IPv4 Mobile Node (MN) Mobile system that can change the cell without changing the IP-address Home Agent (HA) Represent the MN in the home network while the MN is in a foreign network. It knows the location of MN. Tunneling IP-datagramms to MN Foreign Agent (FA) It is the central processor in a foreign network. It relays the tunnelled datagramms to the MN. It makes Care-of-Address available to MN.

15 Mobile IPv4 Correspondent Node (CN) The communications partner of the MN Home Address (HoA) The address, where the MN is reachable in the home network It administrates the location of the MN, if MN is in a foreign network Care-of-Address (CoA) The address of the current endpoint of the tunnel for the MN It shows the current location of MN in the dimension of IP FA-CoA: CoA is by the FA Co-located CoA: MN gets a CoA from the foreign network

16 Mobile IPv4

17 Mobile IPv4 3 steps by Mobile IPv4 Agent Discovery Agent Advertisement (AA) Agent Solicitation (AS) Registration Registration Request Registration Reply Message Digest Tunneling Forward Tunneling Reverse Tunneling

18 Mobile IPv4 Agent Discovery Agent Advertisement HA and FA are sending periodically special messages that they exixt in the physically subnetwork MN hear the messages and recognize if it is in the home- or foreignnetwork MN get to know a CoA from the messages of the FA Agent Solicitation MN itselves send a request to the FA to start a AA AS is used if the FA is not sending itselves or MN don t want to wait MN want that the agents answer immediately MN not receive an Advertising home network

19 Mobile IPv4 Registration MN contact via FA its HA the CoA HA authenticate via FA to the MN These actions must be secure with an authentification

20 Mobile IPv4 Tunneling Problem HA must relays packets to the FA. FA has another IP-address like the MN Base Solution The original packet with Header and Payload are used as Payload of the new IP-packet Header of the new IP-packet includes the IP-address of the FA

21 Reverse Tunneling Mobile IPv4

22 Fast Handover in Mobile IPv4 Low Latency in Mobile IPv4 Goal minimize the time of latency Methods: Supporting by... Movement-Detection IP-address configuration Different modi: Pre-Registration Post-Registration Combination Forwarding of packets

23 Fast Handover in Mobile IPv4

24 Fast Handover in Mobile IPv4 Pre-Registration

25 Fast Handover in Mobile IPv4 Post-Registration

26 Mobile IPv6 Many shared features with MIPv4, but they are integrated on the IP Layer No need for Foreign Agents (FA) Support for route optimization is a fundamental part of the protocol Works out-of-the-box

27 Fast Handover in IPv6 Fast as in minimization of the handover latency FH as an extension to the MIPv6 TCP (Layer 4) should not realise the cell change The idea for the MN is to get a new Adress Router (AR) prematurelly to the loss of the old AR If FH fails, traditional Handover with paket routing from old AR to new AR

28 New Messages for MIPv6 Fast Handover is defined by adding a certain number of new messages between the Access Routers and also between Access Routers and the Mobile Node (MN): Router Solicitation for Proxy (RtSolPr): from MN to oldar Proxy Router Advertisement (PrRtAdv): from oldar to MN Handover Initiate (HI): from oldar to newar Handover Acknowledgement (HAck): from newar to oldar Handover Acknowledgement (HAck): from newar to oldar Fast Binding Acknowledgement (F-BAck): from oldar to MN Fast Neighbour Advertisement (F-NA): from MN to newar

29 Stateless CoA

30 From oldar to newar

31 Summary

32 Questions?

33 Discussion Do you think that we have not enough IPaddresses with IPv4? Where is the handling with the Handover better: in IPv4 or in IPv6?