1. Nitheesh K
VIAHECS030
Department of computer science
CS 640 1

2. Mobile IP
Mobile IP was designed to allow mobile device users to move
from one network to another .
 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.
 Has no geographical limitations.
 Supports security.
Standardized by IETF .
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3. Mobile IP Entities
Mobile Node (MN)
 The entity that may change its point of attachment from
network to network in the Internet.
 Two addresses:-
1. Home address – IP address assigned to the device
within its home network .
2. Care-of address (COA)– IP address of the device when
it is operating in a foreign network.
 Identifies Mobile Node’s current location.
 Sent by Foreign Agent to Home Agent when MN
attaches.
 Usually the IP address of the Foreign Agent.
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4. Mobile IP Entities
Home Network – The network within which the device
receives its Home address
Home Agent (HA)
 Stores information about Mobile nodes whose
permanent Home address is in Home Agent’s Network.
 Located on home network of Mobile Node.
 Does mobility binding of MN’s IP with its COA
 Forwards packets to network when MN is away
 Does this through encapsulation
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5. Mobile IP Entities contd.
Foreign network – Network in which the Mobile Node is
away from its Home network.
Foreign Agent (FA)
 Stores information about mobile nodes visiting its network.
 If MN is away from HA then it uses a FA to send/receive data
to/from HA
 Advertises Care-of addresses which are used by Mobile IP.
 Decapsulates messages for delivery to MN
Binding – Association of Home address with Care-of address.
Correspondent Node(CN) – End host of MN.
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6. Mobile IP Operation
Agent Discovery
 HA’s and FA’s broadcast their presence on each network to which
they are attached
 MN’s listen for advertisement and then initiate registration
Encapsulation – Attaching COA to the packet with HA
Decapsulation –Detaching COA to the packet with HA
Registration
 When MN is away, it registers its COA with its HA
 Registration happens as often as MN changes networks
 There is a specific lifetime for service for registration
 There is also a de-registration process if an MN returns home
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7. Mobile IP Operation
A MN listens for agent advertisement and then initiates
registration
After receiving the registration request from a MN, FA request
to HA
The HA acknowledges and registration is complete
HA intercepts all packets destined for MN
HA then encapsulates all packets addressed to MN and
forwards them to FA
FA decapsulates all packets addressed to MN and forwards
them via hardware address
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8. Registration Process
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9. Tables maintained on routers
Mobility Binding Table
 Maintained on HA of MN
 Maps MN’s home address with
its current COA
Visitor List
 Maintained on FA
 Maps MN’s home address HA
address
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10. Mobile IP Tunneling
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Across Internet

11. Mobile IP Problems
Single HA model may be damaged
Possible solution – have multiple HA
Frequent reports to HA if MN is moving
Applications
Found in Wired and Wireless environments.
Able to carry mobile devices across Multiple LANS.
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12. THANK YOU
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