Nautilus6 - Network Mobility

Network mobility arises when entire networks are changing their point of attachment with respect to the Internet topology. Those are thus referred to as mobile networks and will soon be found in vehicles (taxi, cars, trains) and embedded on people (Personal Area Networks or PANs). A mobile network is connected to the Internet via one or more mobile routers (MR). Nodes behind the MR are referred to as mobile network nodes (MNNs). MNNs are either local fixed nodes (or LFNs, i.e. nodes that belong to the mobile network with no abilities to change their point of attachment), local mobile nodes (or LMNs, i.e. nodes that belong to the mobile network with the ability to change their point of attachment), or visiting mobile nodes (or VMNs, i.e. nodes which do not belong to the mobile network and which are able to change their point of attachment). If no network mobility support functions are provided, all connections between the MNNs and nodes located in the Internet would break as a result of the MR changing its point of attachment.

The IETF NEMO (NEtwork MObility) working group has been created in fall 2002 to standardize a solution for this problem. The NEMO WG has decided to first specify an easy, straight forward, but not optimal solution for this problem referred to as NEMO Basic Support. The solution is to set up a bidirectional tunnel between the home agent (HA) and a mobile router much like it is done in Mobile IPv6. The first version of this solution has been issued in June 2003.

The IETF's NEMO working group is also investigating issues related to specific configurations of mobile networks, such as nested mobile networks (mobile networks that attach in a larger mobile network, such as a PAN that is getting Internet access through a mobile network deployed in a train), multihomed mobile networks (mobile networks with several point of attachment to the Internet), issues related to prefix-delegation and other IPv6 mechanisms, and compatibility issues with other IPv6 protocols, such as multicast. For the long term, the IETF's NEMO working group intends to investigate how the solution could be optimized, i.e. NEMO Extended Support. This includes solutions to improve routing, particularly when there are several levels of mobility (i.e. nested mobile networks).

Network mobility is the key mobility feature to bring all mobility features together. It provides an environment where all IPv6 features must be combined (mobility, multihoming, security and access control, auto-configuration, multicast), particularly mobility activities (host mobility using Mobile IP, network mobility using NEMO, nested mobility using a combination of NEMO and Mobile IP, ad-hoc networking, seamless mobility, micro-mobility). NEMO can thus serve as a glue between all IPv6 features.

The objectives of Nautilus6 in this activity is to develop reference implementations of the standards designed at the IETF, to contribute to the standardization process, to push for the development of additional features which are required for a proper operational use of the protocols, and to investigate potential new solutions for the longer term. This year's activities can thus be split into implementation, testing and research.

NEMO Basic support implementations are available on both Linux (2.6 kernel) and BSD operating systems: check the implementation page.