Host Mobility for IP Networks CSCI 6704 Group Presentation presented by Ye Liang, ChongZhi Wang, XueHai Wang March 13, 2004

Presentation Outline Motivation Motivation Host Mobility Solutions Host Mobility Solutions - Mobile IP - Mobile IP - Host Identity Protocol (HIP) - Host Identity Protocol (HIP) - Migrate - Migrate Comparison Comparison

Motivation Mobile IP was perceived to contain many shortcomings. Mobile IP was perceived to contain many shortcomings. A wide variety of mobility management mechanisms have been proposed. A wide variety of mobility management mechanisms have been proposed. Future for MIP mobility management is not clear. Future for MIP mobility management is not clear. Don’t worry, people are working on it. Don’t worry, people are working on it.

Mobility Management Sits on both the end mobile hosts and the network. Sits on both the end mobile hosts and the network. Requirements: Location-independent identifier, Compatibility with IP routing, Location Management, Transparent, and Security. Requirements: Location-independent identifier, Compatibility with IP routing, Location Management, Transparent, and Security. Available Solutions: Transport, Application, Session mobility, Personal mobility, Service mobility, etc. Available Solutions: Transport, Application, Session mobility, Personal mobility, Service mobility, etc.

Mobile IP – Triangle Routing Download site Mobile host Home Agent Home network Foreign Agent Foreign network uses as its COA register Tunneling

Mobile IP – Route Optimization Download site Mobile host Home Agent Home network Foreign Agent Foreign network uses as its COA register Return Routability Check Binding update

MIP Extension - Micromobility B1 Home agent does not have to be aware of every handoff the mobile node performs. Home agent does not have to be aware of every handoff the mobile node performs. The visited network takes care of the local mobility using a Domain Foreign Agent (DFA) The visited network takes care of the local mobility using a Domain Foreign Agent (DFA) Protocols: HMIP, RAFA, Cellular IP, Hawaii IP, and Hierarchical Mobile IP. Protocols: HMIP, RAFA, Cellular IP, Hawaii IP, and Hierarchical Mobile IP. B3B2 Mobile Device Foreign Network DFA Internet

Problems with TCP/IP Dual roles of IP addresses makes things complex Bad for Mobility and multihoming Location Identifiers Host Identifiers

Architecture of Host Identity Protocol (HIP)  A new layer – a new name space for host identifiers  Sockets are bound to Host Identifies, not IP addresses  Kernel translation between Host identifies and IP address Proposed by Robert Moscowitz to the IETF in

HIP Cont. – Change the architecture  Separate locators from host identifiers  IP addresses still act as location identifiers  A new cryptography-based name space for host identifier

Operations of HIP

Migrate B. Awerbuch and D. Peled proposed a way to use a hierarchical directory service to support location management. B. Awerbuch and D. Peled proposed a way to use a hierarchical directory service to support location management. Snoeren and Balakirshnan proposed this end-to- end Mobility Management. Snoeren and Balakirshnan proposed this end-to- end Mobility Management.

Migrate Cont. Hostname, rather than IP address, is used as the invariant name Hostname, rather than IP address, is used as the invariant name But some transport protocols (i.e TCP) use IP addresses as part of its connection identifier, making migration difficult. But some transport protocols (i.e TCP) use IP addresses as part of its connection identifier, making migration difficult.

Migrate Cont. – session control i.e TCP connection migration i.e TCP connection migration Two TCP segments (SYN and ACK) are used to handle this situation. Two TCP segments (SYN and ACK) are used to handle this situation. IPsec or optional Diffie-Hellman key exchange is used to secure the network. IPsec or optional Diffie-Hellman key exchange is used to secure the network.

MIP, HIP, Migrate Comparison Performance. e.g. per-session packet overhead and latency Performance. e.g. per-session packet overhead and latency Security. Security. Deployment. Deployment. Scalability. Scalability. Robustness. Robustness.

Mobile IP -Strengths Does not require bilateral deployment of host modifications Does not require bilateral deployment of host modifications Can support mobile subnetworks of nodes that d not change addresses dynamically Can support mobile subnetworks of nodes that d not change addresses dynamically Support simultaneous mobility of both communicating nodes. Support simultaneous mobility of both communicating nodes. Micromobility support Micromobility support Longer history of research Longer history of research

Mobile IP - Weaknesses Tunneling and routing headers lead to additional per-packet overheads Tunneling and routing headers lead to additional per-packet overheads Operation with multiple addressing realms Operation with multiple addressing realms Tunneling can conflict with firewall and IPsec security policies Tunneling can conflict with firewall and IPsec security policies Security issues are more complicated by third party agents. Security issues are more complicated by third party agents.

HIP - Strengths Better path selection Better path selection No per packet overhead beyond that of Ipsec No per packet overhead beyond that of Ipsec Natural operation with multiple addressing realms Natural operation with multiple addressing realms Integrated with IP security protocols Integrated with IP security protocols More natural solution to multihoming More natural solution to multihoming

HIP – Weaknesses Short of history and experiences. Short of history and experiences. Deployment barriers. (IPsec deployment) Deployment barriers. (IPsec deployment) Lack of micromobility, mobile router, Lack of micromobility, mobile router, simultaneous node movement capabilities simultaneous node movement capabilities Overhead for short transactions. (Hand shack) Overhead for short transactions. (Hand shack)

Migrate – Strength Better path selection Better path selection Easier integration with NATs and firewalls Easier integration with NATs and firewalls No tunneling overhead No tunneling overhead Does not require additional network infrastructure. Does not require additional network infrastructure.

Migrate - Weaknesses Changes of TCP implementation at both ends Changes of TCP implementation at both ends DNS scalability DNS scalability TCP-centric TCP-centric

Conclusion Mobile IP is much more developed and implemented. Mobile IP is much more developed and implemented. Mobile IP support micromobility and mobile subnets Mobile IP support micromobility and mobile subnets If IPv6 is widespread, then MIPv6 is hard to beat. If IPv6 is widespread, then MIPv6 is hard to beat.

Questions?