What  is a Protocol? What  is  this stuff? Well, a Protocol  is a set of rules, which is used for connecting some computers in a network. As for example a man goes to some different land and want to find his destination. Then there should be some standard pattern for such people to talk to each other or to communicate. These standard patterns are some set of rules with which you need to send your data to this distant land and talk to the person. Thus there is standard set of Protocols without which our communication is impossible for the Network Of Networks or INTERNET. These Protocols are thus called INTERNET PROTOCOLS. 

The day will arrive, hastened by Mobile IP, when no person will ever feel “lost” or out of  touch.  As  people  move  from  place  to  place  with  their  laptop,  keeping  connected  to  the network  can  become  a  challenging  and  sometimes  frustrating  and  expensive  proposition. The goal  is  that with widespread deployment of  the mobile networking  technologies described here automatic communications with globally inter-connected computing resources will be considered as natural for people on the move as it is for people sitting at a high performance workstation in heir office. In the near future communicating via laptop should be as natural as using telephone.

Although  the  Internet offers  access  to  information  sources worldwide,  typically we do not  expect  to  benefit  from  that  access  until we  arrive  at  some  familiar  point  –whether  home, office, or  school. However,  the  increasing variety of wireless devices offering  IP connectivity, such as personal digital assistants, handhelds, and digital cellular phones, is beginning to change ur perceptions of the Internet.

Mobile IP is a proposed standard protocol that builds on the Internet Protocol by making mobility  transparent  to  applications  and  higher-level  protocols  like  TCP.  This  paper  aims  at discussing  the design principles of Mobile  IP  and how  it can be  incorporated with  the already existing Internet architecture.

There are mainly three processes in Mobile IP:
1.  Agent Discovery: The process by which a Mobile node determines  its current  location and obtains the care of address.
2.  Registration: The process by which a Mobile node  request  service  from a  foreign agent on foreign link and informs its home agent of its current care-off address.
3.  Tunneling: The specific mechanism by which packets are routed to and from a Mobile node hat is connected to a foreign link.

Mobile Computing  is becoming  increasingly  important due  to  the  rise  in  the number of portable  computers  and  the  desire  to  have  continuous  network  connectivity  to  the  Internet irrespective of  the physical  location of  the node. The  Internet  infrastructure  is built on  top of a collection of protocols, called  the TCP/IP protocol  suite. Transmission Control Protocol  (TCP) nd Internet Protocol (IP) are the core protocols in this suite. IP requires the location of any host connected to the Internet to be uniquely identified by an assigned IP address. This raises one of he most important issues in mobility, because when a host moves to another physical location, it has to change its IP address. However, the higher level protocols require IP address of a host toe fixed for identifying connections.