Enabling Network Mobility: A Survey of NEMO file:///X:/www-docs/cse574-06/ftp/network_mobility/index.html1 of 12 5/9/2006 7:25 PMEnabling Network Mobility: A Survey of NEMOPaul Moceri [email protected] growing use of IP devices in portable applications has created the demand for mobility support for entire networks of IP devices. Network Mobility (NEMO) solves this problem by extending Mobile IP. Devices on amobile network are unaware of their network's mobility; however, they are provided with uninterrupted Internet access even when the network changes its attachment point to the Internet. The Internet EngineeringTask Force (IETF) has already created a set of NEMO protocols to provide basic NEMO functionality on bothIPv4 and IPv6 and continues to work with other projects to develop advanced performance and functionality enhancing features. The first set of NEMO implementations are available on several platforms including BSDvariants, Linux, and Cisco Systems routing equipment.KeywordsNetwork Mobility, NEMO, Mobile IP, MIPv4, MIPv6, Mobile Networks, Mobility, Survey, Multihoming, Route OptimizationTable of Contents1.0 Introduction1.1 Applications1.2 Terminology1.3 How it Works2.0 Protocols and Standards2.1 NEMO Basic Support Protocol2.2 NEMO on IPv4 vs. IPv63.0 Security and Performance Considerations3.1 Security Features3.2 Performance Analysis3.3 Interoperability4.0 Future Work for NEMO4.1 Route Optimization (RO)4.2 Multihoming4.3 DHCPv6 Prefix Delegation5.0 Implementations5.1 Nautilus6 Project for IPv65.2 Cisco Mobile Networks5.3 Microsoft Windows Support6.0 SummaryReferencesAcronymsEnabling Network Mobility: A Survey of NEMO file:///X:/www-docs/cse574-06/ftp/network_mobility/index.html2 of 12 5/9/2006 7:25 PM1. IntroductionToday, using Mobile IP (MIP), it is possible to move a single IP device from point to point on the Internet without losing higher level connections. However, with the proliferation of IP and the desire to always remainconnected to the Internet, we are seeing entire networks of IP devices moving together from one place toanother. It is possible to enable mobility for all of these devices using standard Mobile IP; however, thiswould require all devices to be capable of Mobile IP and generate excess overhead as every device has to perform Mobile IP functions.Another solution to the problem is Network Mobility (NEMO). NEMO works by moving the mobilityfunctionality from Mobile IP mobile nodes to a mobile network's router. The router is able to change itsattachment point to the Internet in a manner that is transparent to attached nodes. This survey paper will givean overview of NEMO including how it works, current and future NEMO standards, and an overview of implementations and products that support NEMO. Since NEMO draws heavily from Mobile IP, the authorrecommends that the reader is familiar with Mobile IP [RFC3344].1.1 ApplicationsIn the near future, airplanes, automobiles, and even people will carry entire networks of IP devices that connect to the Internet. However, as they move, these networks must change their point of attachment to theInternet due to availability of Internet connectivity. NEMO would enable devices on these networks tomaintain unchanged (in the sense of unchanged IP address and network prefix) connections to other devices on the Internet.Airplanes - Until recently, wireless devices have been prohibited on commercial airline flights due to the risk of interference with airplanes electrical systems. However, in June of 2005, the Federal AviationAdministration (FAA) gave permission to United Airlines to install Wi-Fi (802.11) wireless network equipment on some of its aircraft [Reuters05]. This new regulation will open the door for in-flight Internetservice and invite NEMO as a solution to provide uninterrupted Internet connectivity to multiple passengers.Automobiles - It is not difficult to image networked systems or even Internet enabled navigation, multimedia,or driving system on automobiles. NEMO has the potential to provide a single, shared Internet access point tothese systems. In the case of critical driving systems, NEMO would be essential in order to maintaincontinuous connectivity and availability [Ernst02].Personal Area Networks (PANs) - People are beginning to carry multiple Internet enabled devices such as cell phones, PDAs, laptop computes, and music players. Instead of each device connecting to the Internetseparate, all of devices could connect the Internet through a PAN. Using NEMO, one device, such as a cellphone, would act as the mobile router providing continuous access to the rest of the devices.Other applications and uses of mobile networks can be found in the Network Mobility Support Goals and Requirements Internet-Draft [Ernst05].1.2 TerminologyThe following definitions are important for understanding the basics of Mobile IP and NEMO and will be used throughout this survey paper.Access Router (AR) Router that provides Internet access to a Mobile Router.Enabling Network Mobility: A Survey of NEMO file:///X:/www-docs/cse574-06/ftp/network_mobility/index.html3 of 12 5/9/2006 7:25 PMCare-of Address (CoA) IP address of Mobile Router at its current Internet attachment point.Correspondent Node (CN) An IP device that is communicating with Mobile Network Node via IP.Foreign Agent (FA) An Access Router that is NEMO aware and provides mechanisms to aid the Mobile Router.Home Agent (HA) Host on the Home Network that enables the Mobile Router to roam.Home Network (HN) Network that a Mobile Router belongs to when it is not roaming. i.e. the network thatis associated with the network link of the Home Agent.Mobility Agent (MA) Any IP device, including Mobile Router and Home Agent, that perform mobility functions.Mobile Network Node (MNN) Any IP device on a mobile network. Mobile Network Nodes may be fixed tothe mobile network or visiting the mobile network as mobile nodes. MNNs do not need to be aware of the network's mobility.Mobile Node (MN) An IP device capable of changing its attachment point to the Internet while maintain higher layer connectivity through mobility functionality.Mobile Router (MR) A router capable of changing its point of attachment to the Internet without disrupting higher layer connections of attached devices.For a more complete list of the agents and devices involved in network mobility refer to [Ernst06].1.3 How it WorksThe easiest way to understand NEMO is to first understand Mobile IP. Mobile
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