Presentation on theme: "Mobile Networking through Mobile IP"— Presentation transcript:
1 Mobile Networking through Mobile IP Presenter: Guimin Zhang
2 Truly Mobile Networking Provide confident access to the Internet anytime, anywhereReconnection occurs automatically and noninteractivelyMobility transparent to applications and higher level protocols such as TCP
3 Today’s Internet Protocol Packets are routed to destinations based on IP address
6 Mobile IP Approach Mobile IP uses two IP addresses: Home address: The IP address assigned to the mobile node, making it logically appear attached to its home network.Care-of address: An IP address at the mobile node's current point of attachment to the Internet, when the mobile node is not attached to the home network.
7 Mobile Network Terminology (1) Home network: The network at which the mobile node seems reachable, to the rest of the Internet, by virtue of its assigned IP address.Foreign network: The network to which the mobile node is attached when it is not attached to its home network, and on which the care-of address is reachable from the rest of the Internet.
8 Mobile Network Terminology (2) Home agent: A router on the home network that effectively causes the mobile node to be reachable at its home address even when the mobile node is not attached to its home network.Foreign agent: A router on the foreign network that can assist the mobile node in receiving datagrams delivered to the care-of address.
10 How Mobile IP Works Discovering the care-of address Registering the care-of addressTunneling to the care-of addressRegisterHAFADiscovery
11 Agent Discovery Protocol Extends ICMP Router Discovery protocolICMP Router Discovery Protocol enables hosts attached to multicast or broadcast networks to discover the IP addresses of their neighboring routers.Agent advertisements: The mobile agent broadcast agent advertisements at regular intervals.Agent solicitation: The mobile node broadcast or multicast a solicitation that will be answered by any foreign agent or home agent that receives it.
12 Advertisement Message Formats ICMP Router AdvertisementAgent Advertisement extensionType: 16R: register requiredB: busyH: home agentF: foreign agentM: minimum encapsulationG: GRE encapsulationV: Van Jacobson header compression
13 Advertisement Message Formats ICMP Router AdvertisementPrefix Length extensionType: 19Prefix Length:network number of the corresponding Router Address listed in the ICMP Router Advertisement portion of the message.
14 Mobile Node Move Detection Lifetime basedThe mobile node record the Lifetime of advertisement message. If it fails to receive another advertisement from the same agent until the the Lifetime expires, it considers to find a new agent.Network prefixes basedThe Prefix-length extension is used to determine if the newly received advertisement is in the same subnet as the mobile node’s current care-of-address.
15 RegistrationExchange of Registration Request and Registration Reply messages: UDP using well-known port 434MH: mobile host; FA: Foreign Agent; HA: Home Address
16 Foreign Agent Consideration Each foreign agent must be configured with a care of addressFor each pending or current registration, the foreign agent maintains a visitor list entry containing:Link-layer source address of the mobile nodeThe mobile node’s Home AddressThe Home Agent addressThe identification fieldThe requested registration LifetimeThe remaining Lifetime of the pending or current registration
17 Security Considerations in Registration Danger: Registration Request works remotely to the home agent to affect the home agent's routing tableSecurity:Authentication: Home agents and mobile nodes perform authentication using MD5 algorithm and key size of 128 bits.Replay Protection: The Identification field is used to verify that a registration message has been freshly generated.timestamp , random number
19 Changes with IP Version 6 Route OptimizationWhen it knows the mobile node's current care-of address, a correspondent node can deliver packets directly to the mobile node's home address without any assistance from the home agentSecurityStrong authentication and encryption features are included in IP V6
20 Problems Facing Mobile IP Security issuesRouting inefficiencyTriangle routingIngress filteringUser perceptions of reliabilityCompetition from other protocols
21 Mobile IP Related Projects The CMU Monarch Project: Protocols for Adaptive Mobile and Wireless NetworkingPortland State Secure Mobile Networking ProjectState University of New York, Binghamton's Linux-Mobile IPStanford's Operating Systems and Networking Group's MosquitoNetBBN Technologies' Mobile IP Security page
22 Reference"Mobile Networking through Mobile IP," C. Perkins, IEEE Internet Computing, Vol. 2, No. 1, 1998."Mobile IP ," C. Perkins, IEEE Communications Magazine, Vol. 35, No. 5, 1997.