Fast Handover in Mobile IPv4 and IPv6 Raoul Schmidiger & Gregor Zographos April 28, 2005 Seminar: Mobile Systems Talk No.4
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)
IPv4 From Jon Postel in RFC791 anno 1981 4 th Version of the Internet Protocol (IP) 32-Bit addresses length 24-Bit for the network part 8-Bit for the host part 130.60.48.7 (ifi IP) IP-Packet (1500 Bytes) Header (Informations about source, goals, status, fragments etc.) Payload (includes transporting datas)
IPv4 Make no differences between Hosts/Routers IANA diversify the IP-adresses worldwide In several classes, reserved for special purposes (broadcast, multicast etc.) 4 294 967 296 definite addresses possible Future
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
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
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
IPv6 Adress (1) Unicast, anycast, multicast Adress space now slightly bigga: 340 282 366 920 938 463 463 374 607 431 768 211 456 But practically only 8x10^17 to 2x10^33 will be used. Internet adress in HEX: http://[2a2f:9230:70fe:000e:d108:4b4c:7331:2ff0]/ IPv4 Adress will be stored in the low-order 32-bits to allow the gradual transition from IPv4
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
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!
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
Standards in Mobile IP Security Authentify of registry messages guarantee of the privacy Efficiency As few as possible extra datas to the end-system
Mobile IP
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.
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
Mobile IPv4
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
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
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
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
Reverse Tunneling Mobile IPv4
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
Fast Handover in Mobile IPv4
Fast Handover in Mobile IPv4 Pre-Registration
Fast Handover in Mobile IPv4 Post-Registration
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
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
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
Stateless CoA
From oldar to newar
Summary
Questions?
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?