MOB 6 addressing routing 2010

Anne Fladenmuller Internet & Mobile Communications - 2007 Mobile Communications   Network Layer   DHCP   IP mobility (IPv4 and V6)   Ad hoc routing Internet & Mobile Communications - 2007 2 Network Layer   Identification of each network   Identification of networks’ nodes   Packets redirection   Fragmentation and reassembly Goal: routing and IP packets control. Operations taken into account by IP: Mobility requires modifications mainly in packets redirection functions • QoS management • Triggering of address resolution mechanisms • Information about control and links state Internet & Mobile Communications - 2007 3 Network Layer 132.227.61.18 98.217.15.25 132.227.61.xx 98.217.15.xx 132.227.61.15 Classical routing C From: 98.217.15.25 To: 132.227.61.18 A B D E 132.227.xx E 98.217.15.xx A …. Internet & Mobile Communications - 2007 4 Network Layer WAN 132.227.61.18 98.217.15.25 132.227.61.xx 98.217.15.xx 132.227.61.15 129.210.112.30 129.210.112.xx 132.227.61.18 Terminals mobility Internet & Mobile Communications - 2007 5 WAN 98.217.15.25 132.227.61.xx 98.217.15.xx 132.227.61.15 129.210.112.30 129.210.112.xx 132.227.61.18 From: 98.217.15.25 To: 132.227.61.18 ? Network Layer Terminals mobility Internet & Mobile Communications - 2007 6 Network Layer   Different mobility aspects –  Unfrequent moves from the user with his laptop or PDA.   IP address modification: DHCP.   Macro mobility management. –  Frequent moves from the user: micro mobility management. –  Independant moves of all network devices: Ad Hoc networks. Internet & Mobile Communications - 2007 7 DHCP   Allocation of a new IP address with DHCP (Dynamic Host Configuration Protocol). –  Main goal:   Simplification of network administration.   Nomadism management: user’s move to a new network with his computer –  It allows obtaining a network configuration dynamically:   DHCP is mainly used for IP addresses distribution   It comes from an evolution of BOOTP (Bootstrap Protocol) used to set up machines accross a network.   A DHCP server can return BOOTP parameters or configuration parameters specific to a given host.   RFCs: 1541 Internet & Mobile Communications - 2007 8 DHCP   DHCP protocols principles –  1 DHCP server distributes IP addresses.   The server is a base for all DHCP requests (1 server with a fixed IP address per network).   The fundamental communication mechanism is BOOTP –  When a machine gets started, it has no information about its network configuration. –  To find the DHCP server and dialog with it, the machine will send a particular broadcast packet on the LAN. –  When the DHCP server receives this packet, it answers with another broadcast packet (the client does not necessarily have his IP address and is thus unreacheable directly) which contains all necessary information for the client. Internet & Mobile Communications - 2007 9 DHCP   Allocation of a static or dynamic address –  A DHCP server generally provides dynamic addresses   A same computer can thus receive 2 different addresses one successively –  But it can also provide a fixed IP address to a specific client.   This must be used reasonably, otherwise the DHCP server is more or less useless Internet & Mobile Communications - 2007 10 DHCP   Dialog with the server –  DHCP messages are transmitted through UDP. –  DHCP thus works in an unconnected mode. –  Ports’ numbers:   The client only uses port 68 to send and receive its messages   The server sends and receives its messages on a single port, port 67. –  BOOTP/DHCP frame format   The DHCP frame is indeed the same as BOOTP   Parameters exchange (machine’s name ) is done through options. –  Options are described in RFC2132. They are all identified by a number. For example,   option 15: provides the client with the network’s domain name.   option 53: DHCPACK [...]... Internet & Mobile Communications - 2007 Mobile Communications   IP Mobility   Mobilile IP   Micro Mobility   Mobile IPv6 Different kinds of mobility Home Network Mobile Cellular Network POP POP Internet POP Mobile host Visited LAN POP Mobile host PSTN 25 Mobile host Internet & Mobile Communications - from Gwendal Legrand Mobile host Different kinds of mobility   Nomadic Computing (DHCP) –    Mobile... 32 Internet & Mobile Communications - from Gwendal Legrand Mobility: Vocabulary home network: permanent “home” of mobile (e.g., 137.194. 160 .0) home agent: entity that will perform mobility functions on behalf of mobile, when mobile is remote wide area network Permanent address: address in home network, can always be used to reach mobile e.g., 137.194. 160 . 36 correspondent 33 Internet & Mobile Communications... These documents and other related information may be found at the mobileip WG home page on the Web: http://   www.ietf.org/html.charters/mobileip-charter.html 30 Internet & Mobile Communications - from Gwendal Legrand Mobile Communications   IP mobility   Mobile IP   Micro-mobility   Mobile IPv6   Conclusion How do you contact a mobile friend: Consider friend frequently changing addresses, how... translate addresses keep its address -> change routing Let's see that in more detail now … Internet & Mobile Communications - from Gwendal Legrand Mobile IP standardization process   Standardization of Mobile IP is carried out at the IETF –  The IP Routing for Wireless/Mobile Hosts (mobileip) Working Group is in charge of defining and specifying the Mobile IP architecture and protocols Request For... Legrand Mobility: more vocabulary Home agent : entity in the home network which delivers datagrams to departed mobile nodes, and maintains current location information for each Permanent address: remains constant (e.g., 137.194. 160 . 36) visited network: network in which mobile currently resides (e.g., 132.227 .61 .0) Care-of-address: address in visited network (e.g., 132.227 .61 .134) wide area network Mobile... the datagrams destined to the mobile host to the current attachment point of this host (answers the last IP addresses constraint) 35 Internet & Mobile Communications - from Gwendal Legrand Mobility: approaches     Let routing handle it: routers advertise permanent address of mobile-nodes-in-residence via usual routing table exchange –  routing tables indicate where each mobile located –  no changes... its home network correspondent: wants to communicate with 34 mobile foreign agent: entity in visited network that performs mobility functions on behalf of mobile Internet & Mobile Communications - from Gwendal Legrand The Mobile IP basic concept   The Mobile IP architecture resolves the above contradiction by using 2 IP addresses for a mobile host : –  The Home address (HoA) is a permanent address... indicate where each mobile located –  no changes to end-systems Let end-systems handle it: –  indirect routing: communication from correspondent to mobile goes through home agent, then forwarded to remote –  direct routing: correspondent gets foreign address of mobile, sends directly to mobile 36 Internet & Mobile Communications - from Gwendal Legrand ... AP Station AP Station Station Station Station Station BSS BSS ESS 27 Internet & Mobile Communications - from Gwendal Legrand Requirements of the IP mobility architecture   Two major requirements arise when considering IP mobility: –  Application transparency : Dealing with a mobile configuration should not necessitate a mobile-aware application   needed to avoid application replacement on all Internet... whatever the access network used by the mobile roaming user Dealing with mobility at the IP layer provides a way to answer the above requirements Internet & Mobile Communications - from Gwendal Legrand Mobility in the Internet   IP address –  –    TCP transport session –    –  29 4-tuple: Host moves –    used as a routing directive used as an end-point . Fladenmuller Internet & Mobile Communications - 2007 Mobile Communications   Network Layer   DHCP   IP mobility (IPv4 and V6)   Ad hoc routing Internet & Mobile Communications -. Internet & Mobile Communications - 2007 3 Network Layer 132.227 .61 .18 98.217.15.25 132.227 .61 .xx 98.217.15.xx 132.227 .61 .15 Classical routing C From: 98.217.15.25 To: 132.227 .61 .18 A. & Mobile Communications - 2007 4 Network Layer WAN 132.227 .61 .18 98.217.15.25 132.227 .61 .xx 98.217.15.xx 132.227 .61 .15 129.210.112.30 129.210.112.xx 132.227 .61 .18 Terminals mobility