CS 80240333,CUI Yong,1,Mobile IP -Mobility Support in Internet,CS 80240333 Instructor: CUI Yong,CS 80240333,CUI Yong,2,Outline,Introduction Concepts and glossary in mobile ipv4 Overview of MIPv4 Mobile IP Functions Agent Discovery Registration Tunneling Challenges in MIPv4 Route Optimization in Mobile IP Supporting Fast Handoffs in Mobile IP Conclusions,CS 80240333,CUI Yong,3,How to contact a mobile friend,Turn to her parents? Parents are stable She has a new contact She will tell her parents where she is,Suppose you have a friend who likes traveling and frequently changes address. How to contact her?,Where is she?,CS 80240333,CUI Yong,4,Scenario 1,Computers get wireless access to the internet,No mobility actually,166.111.81.x,Wired network,CS 80240333,CUI Yong,5,Internet,ADSL ISDN 802.11,Scenario 2,Bring notebook back home,Wired environment Offline while moving,CS 80240333,CUI Yong,6,Scenario 3,Access to internet in train,Wireless environment Online while moving,CS 80240333,CUI Yong,7,Mobility from network view,stable,mobile,wireless users by fixed AP,Online mobile users (handoff),Offline mobile users (roaming),CS 80240333,CUI Yong,8,Internet and IP,BS,Company network,Local ISP,Region ISP,IP,Hub, Switch, Router?,CS 80240333,CUI Yong,9,Problems in movement,166.111.80.11,166.111.203.0,166.111.129.0,One or two things? Disconnection while moving（handoff） MN cant be called（roam）,166.111.203.99,166.111.129.88,166.111.80.0,IP protocol and IP address is very important!,CS 80240333,CUI Yong,10,Two kinds of mobility,1) Seamless mobility Mobility is totally transparent to applications 2) Portability Mobility is not transparent to applications when we move, but we can still access the network at a new place Some protocols support either one of them DHCP can support portability Mobile IP can support seamless mobility,CS 80240333,CUI Yong,11,Requirement,To the point of attachment We have seen that mobile users can change point of attachment In a cellular network, a mobile changes base station. In a WLAN, a mobile changes access point. A mobile user can work at office and at home at different in a day: mobile changes Ethernet subnets. To the applications We want applications to be not disturbed from mobility We want to continue to talk with our cell-phone when we change base-stations We want to continue to run telnet when we change access points in a Wireless LAN. ,CS 80240333,CUI Yong,12,Mobility Solutions,Protocols and solutions Mobile Cellular Telephone Networks Solution GSM has its own registration, handoff, mobility management procedures Mobile Internet Solution Mobile IP has been developed to support IP based hosts and mobile users. We will look to Mobile IP in this course,CS 80240333,CUI Yong,13,Mobile IP,Mobile IP is a layer-3 (network layer) mobility solution to support mobile users in the Internet in a seamless manner. We will not be concerned about how mobile stations change physical point of attachments at the Physical layer.,CS 80240333,CUI Yong,14,Mobile IP,Mobile IP is a solution that is independent of the physical and data-link layers: It can work for Ethernet, Token Ring, Wireless LANs, PPP over serial cables or phone lines, etc. By use of Mobile IP, all TCP/IP applications are unaware of the fact that the users are moving Only IP protocol and lower layers are aware of mobility Higher protocol layers (TCP, UDP, RTP, etc) and applications are not aware of mobility.,CS 80240333,CUI Yong,15,Mobile IP,Mobile IP,Ethernet,Token Ring,PPP,WLAN 802.11b,Bluetooth,TCP,UDP,Network Applications and Protocols Telnet, FTP, HTTP, etc.,Mobility is seamless to these.,The link layer can be anything.,TCP/IP Protocol STACK,CS 80240333,CUI Yong,16,Why we need mobile IP,Initial design of Internet was for these computers. Initially we had desktops, workstations, main-frames and super-computer They are static and you can not carry them with you! Now, we have Laptop and handheld computers Palmtop and Pocket PC They are powerful enough for interesting network applications We need Wireless network Internet access technologies for these highly mobile computers and devices to support mobile applications Mobile IP has been designed for this purpose!,CS 80240333,CUI Yong,17,Why we need mobile IP (cont),Come back to the current Internet Current Internet architecture and protocols (without mobile IP support) do not support seamless mobility for mobile users Internet is designed assuming hosts (computer) are static and do not change location frequently. When you move to a new location with your laptop and connect it to a Ethenet cable at the new location, you have to re-confgure your laptop. When you re-confgure your laptop with this information, most of the time you have re-start your laptop. Whether you re-start or not your laptop, previously running network applications will stop working properly when you change the IP address of your laptop.,CS 80