MOBILE IP_INTRODUCTION_OVERVIEW OF MOBILE IP_KEY MECHANISMS OF MOBILE IP_SCHEMATIC MODEL OF MOBILE IP_TUNNELLING_CARE OF ADDRESS-TCP_PACKET FORWARDING_TCP SLIDING WINDOWS

1. MOBILE IP

2. DEFNITION OF MOBILE IP
INTRODUCTION:
Mobile IP is a communication protocol (created by extending
Internet Protocol, IP) that allows the users to move from one network
to another with the same IP address. It ensures that the
communication will continue without user’s sessions or connections
being dropped.

3. OVERVIEW OF MOBILE IP:
Mobile IP (Internet
Protocol) enables the transfer of
information to and from mobile
computers, such as laptops and
wireless communications. The
mobile computer can change its
location to a foreign network
and still access and communicate
with and through the mobile
computer's home network.

4. KEY MECHANISM OF MOBILE IP:
The Mobile IP process has three main phases, which are discussed in
the following sections.
I. Agent Discovery:
A Mobile Node discovers its Foreign and Home Agents during
agent discovery
II. Registration:
The Mobile Node registers its current location with the Foreign
Agent and Home Agent during registration.

6. AGENT DISCOVERY:
During the agent discovery
phase, the Home Agent and Foreign
Agent advertise their services on
the network by using the ICMP
Router Discovery Protocol (IRDP).
The Mobile Node listens to these
advertisements to determine if it is
connected to its home network or
foreign network.

7. A Foreign Agent care-of address is an IP address of a Foreign Agent that has an interface on
the foreign network being visited by a Mobile Node. A Mobile Node that acquires this type of care-of
address can share the address with other Mobile Nodes. A co-located care-of address is an IP address
temporarily assigned to the interface of the Mobile Node itself.
Registration
The Mobile Node is configured with the IP address and mobility security association (which
includes the shared key) of its Home Agent. In addition, the Mobile Node is configured with either its
home IP address, or another user identifier, such as a Network Access Identifier.
Tunneling
1.The Mobile Node sends packets using its home IP address, effectively maintaining the
appearance that it is always on its home network. Even while the Mobile Node is roaming on foreign
networks, its movements are transparent to correspondent nodes.
2.sData packets addressed to the Mobile Node are routed to its home network, where the Home
Agent now intercepts and tunnels them to the care-of address toward the Mobile Node.
Tunneling has two primary functions: Encapsulation of the data packet to reach the tunnel endpoint,
and Decapsulation when the packet is delivered at that endpoint.

8. PACKET FORWADING:

9. TCP:
TCP is a connection-oriented transport protocol that sends data as an
unstructured stream of bytes. By using sequence numbers and acknowledgment
messages, TCP can provide a sending node with delivery information about packets
transmitted to a destination node.
Where data has been lost in transit from source to destination, TCP can
retransmit the data until either a timeout condition is reached or until successful
delivery has been achieved. TCP can also recognize duplicate messages and will
discard them appropriately. If the sending computer is transmitting too fast for the
receiving computer, TCP can employ flow control mechanisms to slow data transfer.

10. TCP SLIDING WINDOWS:
TCP sliding window controls the flow and communication which allows
multiple packet
to e sent and confirmed with single acknowledge packet.
TCP siding window protocol helps the rate of data transmission rate, when
congestions start to develop.
The size of the TCP determine the number of acknowledge sent for data
transfer.