The NEMO Working Group is concerned with managing the mobility of an entire network, which changes, as a unit, its point of attachment to the Internet and thus its reachability in the topology. The mobile network includes one or more mobile routers (MRs) which connect it to the global Internet. A mobile network is assumed to be a leaf network, i.e. it will not carry transit traffic. However,it could be multihomed, either with a single MR that has multiple attachments to the internet, or by using multiple MRs that attach the mobile network to the Internet. Initially,the WG will assume that none of the nodes behind the MR will be aware of the network's mobility, thus the network's movement needs to be completely transparent to the nodes inside the mobile network. This assumption will be made to accomodate nodes inside the network that are not generally aware of mobility. A basic approach for network mobility support is for each Mobile Router to have a Home Agent, and use bidirectional tunneling between the MR and HA to preserve session continuity while the MR moves. The MR will acquire a Care-of-address from its attachment point much like what is done for Mobile Nodes using Mobile IP. This approach allows nesting of mobile networks, since each MR will appear to its attachment point as a single node. The WG will take a stepwise approach by standardizing some basic support mechanisms based on the bidirectional tunneling approach, and at the same time study the possible approaches and issues with providing more optimal routing than can be had with (potentially nested) tunneling. However, the WG is not chartered to actually standardize a solution to such route optimization for mobile networks at this point in time. The WG will work on: - A threat analysis and security solution for the basic problem (tunneling between HA and MR) - A solution to the basic problem for both IPv4 and IPv6. The solution will allow all nodes in the mobile network to be reachable via permanent IP addresses, as well as maintain ongoing sessions as the MR changes its point of attachment within the topology. This will be done by maintaining a bidirectional tunnel between the MR and its Home Agent. The WG will investigate reusing the existing Mobile IPv6 mechanisms for the tunnel management, or extend it if deemed necessary. - An informational document which specifies a detailed problem statement for route optimization and looks at various approaches to solving this problem. This document will look into the issues and tradeoffs involved in making the network's movement visible to some nodes, by optionally making them "NEMO aware". The interaction between route optimization and IP routing will also be described in this document. Furthermore, security considerations for the various approaches will also be considered. The WG will: - Ensure that solutions will scale and function for the different mobile network configurations, without requiring changes to Correspondent Nodes in the Internet. All solutions will aim at preserving route aggregation within the Internet and will satisfy an acceptable level of security (a thorough survey of new threats and an analysis of their severity will be conducted) - Ensure that various mechanisms defined within other IETF WGs will be useful for mobile networks. To achieve this, the NEMO WG will interact with other WGs when needed, and may place requirements on the protocols developed by those WGs. The WG will not: - consider routing issues inside the mobile network. Existing routing protocols (including MANET protocols) can be used to solve these problems.