View
20
Download
0
Category
Preview:
Citation preview
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
� 4th 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 lowbandwith 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 exponentialThe 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,H1b) Request: H1,P1,P2,P3,H2 Response: H2,P3,P2,P1,H1c) …
� 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 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
� 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 foreign-network
� 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
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
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
Recommended