Mobile IP V4

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Mobile IP V4

• Santhosh Rajathayalan (25764968)
• Senthil Kumar Sevugan (42762375)

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Cellular Networks
Cellular Technology Architecture Data Mobility Protocol Authentication/Authorization
GSM/GPRS Circuit Switched Voice, Packet Switched Data GPRS/Mobile IP HLR/HSS
CDMA2000 1x-RTT Circuit Switched Voice, Packet Switched Data Mobile IP HLR/HSS
CDMA2000 1x-EV-DO Packet Switched Data Mobile IP HLR/HSS
Mobile WiMAX Packet Switched Voice And Data Mobile IP AAA Server , RADIUS
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CDMA 2000 Network Architecture
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WiMAX Network Architecture
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• Mobile IP was developed as a means for
  transparently dealing with problems of mobile
  users
• Enables hosts to stay connected to the Internet
  regardless of their location
• Enables hosts to be tracked without needing to
  change their IP address
• Requires no changes to software of non-mobile
  hosts/routers
• Requires addition of some infrastructure
• Requires no modifications to IP addresses or IP
  address format
• Supports security

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• Network Entities
• Mobile Node (MN)
• The entity that may change its point of
  attachment from network to network in the
  Internet
• -Detects and registers with best FA
• Assigned a permanent IP called its home address
  to which other hosts send packets regardless of
  MNs location
• Since this IP doesnt change it can be used by
  long-lived applications as MNs location changes.
• Home Agent (HA)
• This is router with additional functionality
• Located on home network of MN
• Does mobility binding of MNs IP with its COA
• Forwards packets to appropriate network when MN
  is away

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• Network Entities
• Foreign Agent (FA)
• Another router with enhanced functionality
• If MN is away from HA the it uses an FA to
  send/receive data to/from HA
• Advertises itself periodically
• Forwards MNs registration request
• Decapsulates messages for delivery to MN.
• Care-of-address (COA)
• Address which identifies MNs current location
• Sent by FA to HA when MN attaches
• Usually the IP address of the FA
• Correspondent Node (CN)
• End host to which MN is corresponding (eg. a web
  server)

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Messages Involved Proxy Registration Request
(PRRQ) The Registration Request message is sent
by the Proxy Mobility Agent/MN to the Home Agent
in order to set up a mobility binding entry for
a mobile device. Proxy Registration Reply
(PRRP) The Registration Reply message is sent by
the Home Agent in response to the Proxy
Registration Request received from the Proxy
Mobility Agent/MN.
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• Types of Mobile IP
• Client Mobile IP
• Proxy Mobile IP
• RFC 5563 - WiMAX Forum / 3GPP2 Proxy Mobile IPv4

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• Proxy Mobile IPv4
• Provides mobility support without "touching"
  these Mobile Devices.
• Proxy Mobile IPv4 Client (PMIPv4 Client)
• is responsible for initiating and maintaining
  the Proxy Mobile IPv4 registration on behalf of
  the mobile device.
• It performs the Mobile IPv4 client function but
  is hosted in the network. In some cases, this
  function is collocated with the Foreign
  Agent(FA)

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• Proxy Registration During Initial Network
  Attachment
• Involves three stages
• Authentication and authorization happen when the
  mobile device accesses the network.
• Mobile device attempts to obtain an IP address.
  This triggers Proxy Mobile IP, which
  assigns/authorizes the IP address.
• The mobile device configures its IP stack with
  the IP address and the obtained host
  configuration.

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• Proxy Registration During Initial Network
  Attachment
• Mobile device establishes a L2 (Layer 2) link
  with the base station and performs access
  Authentication/authorization with the AR(Access
  Router).
• AR contains the AAA client which exchanges AAA
  messages with the AAA infrastructure to perform
  authentication and authorization of the mobile
  device.
• The mobile device requests an IP address.
• The PMA sends a Proxy Registration Request (PRRQ)
  to the HA.
• The Home Agent sets up the mobility binding entry
  for the mobile device after assigning an IP
  address

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• Tables maintained in the Router
• Visitor Table
• Maintained on FA serving an MN.
• Maps MNs home address to its MAC address
  and HA address
• Mobility Binding Table
• Maintained on HA of MN.
• Maps MNs Home Address
• with its current CoA.

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• Mobile IP functionality
• Registering the Care-of Address
• Tunneling to the Care-of Address

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• Proxy Registration During Mobility
• Mobile device enters into a new network and
  establishes a L2 (Layer 2) link with the base
  station and performs access authentication/authori
  zation with the AR(Access Router).
• The mobile device requests an IP address.
• Triggered by successful authentication, the
  PMA/FA sends a PRRQ to the HA.
• The Home Agent sets up the mobility binding
  entry for the mobile device with its new Care of
  Address(CoA).
• Now HA sends a PRRP message to New PMA , which
  then creates a Tunnel to forward data.
• Because the forwarding path is established
  between the new PMA and HA, the mobile device can
  receive or send IP packets using the Home
  Address.

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• Registration Revocation
• Triggered by the update of the mobility binding
  entry for a mobile device that has moved to a
  new AR.
• The HA may send a Registration Revocation to the
  old PMA (i.e., specifically to the Foreign Agent
  entity) in order to clean up unused resources in
  an expeditious manner.
• The old PMA removes the PMIPv4 states for the
  mobile device.
• The old PMA sends revocation acknowledgement to
  the HA.

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• Reverse Tunneling
• In the upstream direction if MS sends packets
  directly to the correspondent node, there is a
  mismatch.
• Now MS is in network with prefix 192.8.2.
  Security devices (e.g., firewalls) may filter out
  these packets since it may mark them as illegal
  IP source addresses. This is to protect network
  to some types of denial of service attacks.
• Reverse tunneling addresses this issue by
  reversing the outgoing transmission as in the
  incoming route. MS sends the packets to FA, FA
  tunnels them to HA, and HA removes the tunnel and
  forwards the packet to the final destination.

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• Appearance of Being at Home Network
• Mobile Node is not aware of its mobility and does
  not participate in handover signaling.
• The network entities emulate the home network to
  the mobile device attached on the network. From
  the mobile devices perspective, it operates as
  if it were at the home network.
• The network is directing the mobile devices
  traffic to and from its current location and will
  continue to do so when it moves to a new location

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• Forwarding between Devices on Same PMA
• When the communication peers are both attached to
  the same PMA.
• The traffic between them should be routed via the
  HA without taking a local shortcut on the PMA.
• This ensures that data-traffic enforcement at the
  HA is not bypassed.

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Thank you