Mobile Communications-Network Protocols/Mobile IP Presented by: Indhra Priya Shanmugam Submitted To: Professor Ivan Stojmenovic

WHY MOBILE IP The node must change its IP address whenever it changes its point of attachment. (impossible for a node to maintain transport and higher layer connections when the node changes location) Host-specific routes must be propagated throughout much of the Internet. (does not scale very well) Indhra P Shanmugam, Wireless Networks and Mobile Computing

Mobile IP is an Internet Engineering Task Force (IETF) standard communications protocol that is designed to allow mobile device users to move from one network to another while maintaining a permanent IP address. Indhra P Shanmugam, Wireless Networks and Mobile Computing

system in the home network of the MN, typically a router Mobile Node (MN) system (node) that can change the point of connection to the network without changing its IP address Home Agent (HA) system in the home network of the MN, typically a router registers the current location of the MN, tunnels IP datagram's to the COA Foreign Agent (FA) system in the current foreign network of the MN, typically a router De-tunnels and delivers datagram's to the MN Care-of Address (COA) address of the current tunnel end-point for the MN (at FA or MN) actual location of the MN from an IP point of view can be chosen, e.g., via DHCP Correspondent Node (CN) communication partner Indhra P Shanmugam, Wireless Networks and Mobile Computing

HOW MOBILE IP WORKS 2 1 6 3 4 5 Indhra P Shanmugam, Wireless Networks and Mobile Computing

Agent Advertisement Registration Tunneling FUNCTIONS OF MOBILE IP The main functions of Mobile IP are: Agent Advertisement Registration Tunneling Indhra P Shanmugam, Wireless Networks and Mobile Computing

AGENT ADVERTISEMENT Agent Discovery MN detect whether its has moved and it is connected to Home Network (HN) or Foreign Network (FN) Agent Advertisement Routers broadcast an advertisement to links to offer services ICMP Router Advertisement Message. Two types of Message Agent Solicitation Indhra P Shanmugam, Wireless Networks and Mobile Computing

Agent Solicitation When a MN needs information about Foreign agents, it broadcasts Solicitation messages Foreign Agents respond with a router advertisement message directly to the MN. Type: 10 Code: 0 Reserved: 0 Checksum: 0 Indhra P Shanmugam, Wireless Networks and Mobile Computing

AGENT ADVERTISEMENT type = 16 length = 6 + 4 * #COAs R: registration required B: busy, no more registrations H: home agent F: foreign agent M: minimal encapsulation G: GRE encapsulation r: =0, ignored T: FA supports reverse tunneling reserved: =0, ignored Indhra P Shanmugam, Wireless Networks and Mobile Computing

REGISTRATION MN communicate their reachability to HA MN request service when visiting FN MN inform HA the current COA Deregister Indhra P Shanmugam, Wireless Networks and Mobile Computing

REGISTRATION CRTITERIA There are 2 types Registration Procedures: Through Foreign Agent Directly with Home Agent If MN registering a Foreign Agent COA , then register via FA If MN got an advertisement from FA, then register via Foreign Agent If MN has returned to HA, it registers directly with its Home Agent If MN is using Co-located COA, it registers naturally with its HA Indhra P Shanmugam, Wireless Networks and Mobile Computing

REGISTRATION MESSAGE Registration messages in Mobile IP use the User Datagram Protocol (UDP). There are two registration Message: Registration Request Registration Response Indhra P Shanmugam, Wireless Networks and Mobile Computing

AUTHENTICATION To allow additional security for registration process, Mobile IP defines registration extensions: Mobile-Home Authentication extension Mobile-Foreign Authentication extension Foreign-Home Authentication extension Each extension includes SPI and IP address that contains secret information needed to compute others The default algorithm uses MD5(Message Digest) to authenticate the request and response messages Indhra P Shanmugam, Wireless Networks and Mobile Computing

AUTHENTICATION FORMAT Secret key is used both – Prefix and Suffix to data SPI selects authentication algorithm, mode and secret key used in authenticator SENDER = Message + algorithm +secret key RECEIVER = Message Received + algorithm to be used + Secret Key IF Sender = Receiver ( Authenticated) Indhra P Shanmugam, Wireless Networks and Mobile Computing

TUNNELING After successful Registration, Mobile IP requires encapsulation to deliver datagram The encapsulation and decapsulation methods are called tunneling When data transfer, Home agent intercepts the data sent to MN and tunnels them to the COA of MN There are 3 main Tunneling algorithm: IP-in-IP Encapsulation (Default) Minimal Encapsulation Generic Record Encapsulation (GRE) Indhra P Shanmugam, Wireless Networks and Mobile Computing

IP-IN-IP ENCAPSULATION IP datagram is encapsulated within another IP datagram. Data is carried as payload Outer header is added before existing IP header Additional headers can be added for security reasons Indhra P Shanmugam, Wireless Networks and Mobile Computing

MINIMAL ENCAPSULATION Devised to avoid redundancy from IP-in-IP Datagram should be not fragmented before encapsulation Minimal Forwarding Header is used No additional IP header is added Indhra P Shanmugam, Wireless Networks and Mobile Computing

GRE ENCAPSULATION It is more general method. Also used for many other Protocols Indhra P Shanmugam, Wireless Networks and Mobile Computing

REVERSE TUNNELING Tunneling starts at the HA and is decapsulated by either FA or MN (end) Decapsulation depends on type of COA Foreign Agent COA – FA Co-located COA – MN When MN sends message to CN, the process is called Reverse Tunneling Indhra P Shanmugam, Wireless Networks and Mobile Computing

ROUTE OPTIMIZATION One of the problem with Mobile IP – Triangle Routing To overcome this, Route Optimization is implemented Indhra P Shanmugam, Wireless Networks and Mobile Computing

ROUTE OPTIMIZATION OVERVIEW There are 4 operations in Route Optimization: Binding Caches: It maintains COA of mobile nodes and directly tunnels data to MN Manage Smooth Handoff: When MN moves from one FA to another Registration Keys: Securely perform operations for handoff and authentication Using Special Tunnels: To perform tunneling in special cases Indhra P Shanmugam, Wireless Networks and Mobile Computing

ROUTE OPTIMIZATION MESSAGE FORMATS There are 4 Message Formats: Binding Warning Message: To warn MN that it has no cache entry When MN detunnels and is not in current FA Binding Request Message: Request for MN’s current mobility binding Binding Update Message: Update or notify MN’s current mobility binding Binding Acknowledge Message: Acknowledge the receipt of update message Indhra P Shanmugam, Wireless Networks and Mobile Computing

MOBILE IP - ROUTE OPTIMIZATION Indhra P Shanmugam, Wireless Networks and Mobile Computing

SECURITY IN MOBILE IP Network Security in Mobile IP is important. Compromise in Security may lead too: Unauthorized access Disclosure of information Unreliability Denial of Service Corruption of Data Indhra P Shanmugam, Wireless Networks and Mobile Computing

SECURITY ENHANCEMENTS Security can be maintained in Mobile IP using: Confidentiality Authentication Non-Repudiation Integrity Authorization Security in IP Firewall Indhra P Shanmugam, Wireless Networks and Mobile Computing

FUTURE OF MOBILE IP Mobile IP is the Voice and Data of Future It is currently used in: 3G Wireless, CDMA, GSM VOIP Services VPN CISCO WLAN IOS Campus Mobility Metro Mobility Indhra P Shanmugam, Wireless Networks and Mobile Computing

Indhra P Shanmugam, Wireless Networks and Mobile Computing

Question – 1: In Mobile IP Protocol, Explain with Diagram how the Registration Process takes place: a) When Mobile Node (MN) is in Home Network (HN) b) When Mobile Node (MN) is in Foreign Network (FN) Indhra P Shanmugam, Wireless Networks and Mobile Computing

Question – 2: In Mobile IP Protocol, a) What are the three main Tunneling algorithm? b) Which approach is used to solve the Triangle Routing Problem and explain its message Format ? Answer : a) The three main Tunneling algorithm are : IP-In-IP Encapsulation Minimal Encapsulation GRE Encapsulation b) Route Optimization. Its message format are : Binding Warning Message Binding Request Message Binding Update Message Binding Acknowledgement Message Indhra P Shanmugam, Wireless Networks and Mobile Computing

Question – 3: The given diagram explains how datagrams are transferred from Correspondent Node (CN) to Mobile Node (MN) in the current Foreign Agent (FA) using Mobile IP Protocol. Consider that the Mobile Node moved from Foreign Agent Old to Foreign Agent New. Using Route Optimization, Complete the following diagram, explaining how a Mobile Node can move from FA old to FA new. Indhra P Shanmugam, Wireless Networks and Mobile Computing

Answer: Indhra P Shanmugam, Wireless Networks and Mobile Computing

REFERENCES C. Perkins, Mobile IP: Design Principles and Practice, Addison-Wesley Longman Handbook of Wireless Networks and Mobile Computing, Edited by Ivan Stojmenovic Stefan Raab and Madhavi W. Chandra, Mobile IP Technology and Applications Abdul Sakib Mondal, Mobile IP – Present State and Future Dr.-Ing. Jochen Schiller, http://www.jochenschiller.de/ http://ubiquity.acm.org/article.cfm?id=1217824 http://en.wikipedia.org/wiki/Mobile_IP#Applications Indhra P Shanmugam, Wireless Networks and Mobile Computing

Indhra P Shanmugam, Wireless Networks and Mobile Computing