16-1©2008 Raj JainCSE574SWashington University in St. LouisMobile IPMobile IPPart I: IPv4Part I: IPv4Raj JainProfessor of Computer Science and Engineering Washington University in Saint LouisSaint Louis, MO 63130Audio/Video recordings of this lecture are available at:http://www.cse.wustl.edu/~jain/cse574-08/16-2©2008 Raj JainCSE574SWashington University in St. LouisOverviewOverview! Mobile IP: Terminology! Processes: Registration, Advertisements, ..! Security Issues! Reverse Tunneling! Home Networks with Dynamic IP Address! Dynamic Home Agent Assignment! Network Mobility (NEMO)! Mobile IP and VPN16-3©2008 Raj JainCSE574SWashington University in St. LouisMobile IP: FeaturesMobile IP: Features! You can take you notebook to any location! Your TCP connection can continue. TCP connections are from one IP address to another IP address⇒ TCP is unaware of the mobility! Continuous access to your home resources! Access to local resources: Printers! Finds nearby IP routers and connects automatically ! Your IP messages are delivered to your new location! Only "Mobility Aware" routers and mobile units need new s/w! Other routers and hosts can use current IP! No new IP address formats.! Secure: Allows authentication16-4©2008 Raj JainCSE574SWashington University in St. LouisMr. Smith Goes to WashingtonMr. Smith Goes to Washington! We need:" An agent at home office: Home Agent" An agent at foreign office: Foreign AgentMr. SmithCan I speak to Mr. SmithHello Senator TaylorCan you connect me to Mr. Smith?Hello Senator TaylorHotelOperatorMr. Smith’s officeJim TaylorMr. Smith! Call from Taylor16-5©2008 Raj JainCSE574SWashington University in St. LouisMobile IP: TerminologyMobile IP: Terminology! Mobile Node (MN)! Home Agent (HA), Foreign Agent (FA)! Care-of-address (COA): Address of the end-of-tunnel towards the mobile node! Correspondent Node (CN)! Home Address: Mobile’s permanent IP addressHomeAgentMobileNodeCorrespondentNodeForeignAgentHome netNodemovesNew netMobileNode16-6©2008 Raj JainCSE574SWashington University in St. LouisTerminologyTerminology! Home Address: Long-term IP address of the mobile on the home network! IP Access Address: Local IP address of the mobile on the foreign network! Care-of-Address: Address to which the packets are sent by the home agent. Destination of the IP tunnel between home agent and the mobile. Generally COA=IP Access Address! Mobility Agent: Home agent or foreign agent! Agent Advertisement: Periodic advertisement from mobility agents! Correspondent Node: The node communicating with mobile! Foreign Network: Any network other than the home network! Gratuitous ARP: Sent by home agent to update other node’s ARP cache16-7©2008 Raj JainCSE574SWashington University in St. LouisTerminology (Cont)Terminology (Cont)! Mobility Binding: Binding between home address and COA ! Tunnel: Path followed by an encapsulated packet! Mobile Router: A router with changing point of attachment! Mobile Host: A end host (not a router) ! Mobile Node: Mobile Host or Mobile Router! Mobile Network: An entire network that changes its point of attachment! Mobile Network Node: A node in a mobile network. May itself be mobile (visiting) or fixed (permanent) member of the network.! Roaming: Getting connectivity from a foreign network based on a formal agreement between foreign and home network service providers16-8©2008 Raj JainCSE574SWashington University in St. LouisTerminology (Cont)Terminology (Cont)! Handover: Changing the point of attachment! L2 Handover: Moving from one access point to another access point in the same IP network (same network prefix)! L3 Handover: Moving from one IP network to another.Moving from one access router to another access router! Horizontal Handover: Moving between same technology. WLAN to WLAN or 3G to 3G! Vertical Handover: Moving between different technologies. WLAN to 3G.! Push Handover: Previous access router initiates handover! Pull Handover: New access router initiates handover16-9©2008 Raj JainCSE574SWashington University in St. LouisTerminology (Cont)Terminology (Cont)! Make-Before-Break: Make a new connection before disconnecting previous. Will communicate with both for some time.! Break-before-Make: Disconnect previous and then connect with next.! Handover Delay: Time between break and make.! Smooth Handover: Minimize packet loss. Handover delay not critical.! Fast Handover: Minimize handover delay. Packet loss not critical.! Seamless Handover: No change in quality, security, or capability of service.16-10©2008 Raj JainCSE574SWashington University in St. LouisTerminology (Cont)Terminology (Cont)! Diversity: Ability to receive two signals at the same time.! Micro Diversity: Two signals between the same subscriber and base station! Macro Diversity: Two signals from different base stations! IP Diversity: Packets from two IP networks! Micro Mobility: Mobility within a single network. No effect outside the network. a.k.a. Local Mobility.! Macro Mobility: Mobility between networks. Requires Mobile IP type solution. a.k.a. Global Mobility.16-11©2008 Raj JainCSE574SWashington University in St. LouisMobile IP: ProcessesMobile IP: Processes! Agent Discovery: To find agents" Home agents and foreign agents advertise periodically on network layer and optionally on datalink " They also respond to solicitation from mobile node " Mobile can send solicitation to Mobile agent multicast group 224.0.0.11" Mobile selects an agent and gets/uses care-of-address! Registration" Mobile registers its care-of-address with home agent.Either directly or through foreign agent" Home agent sends a reply to the CoA" Each "Mobility binding" has a negotiated lifetime limit" To continue, reregister within lifetime16-12©2008 Raj JainCSE574SWashington University in St. LouisProcesses (Cont)Processes (Cont)! Return to Home:" Mobile node deregisters with home agent sets care-of-address to its permanent IP address" Lifetime = 0 ⇒ Deregistration! Deregistration with foreign agents is not required. Expires automatically! Simultaneous registrations with more than one COA allowed (for handoff)16-13©2008 Raj JainCSE574SWashington University in St. LouisEncapsulation/TunnelingEncapsulation/Tunneling! Home agent intercepts mobile node's datagrams and forwards them to care-of-address! Care of Address can be the Foreign Agent or it can be co-located in the mobile host! Home agent tells local nodes and routers to send mobile node's datagrams to it! De-encapsulation: Datagram is
View Full Document
Unlocking...