This paper incorporates editorial changes from to the output from Subgroup N1 to Working Group N.
Considering the dominant position of the Internet Protocol Suite (IPS) in the commercial networking environment, the Air Navigation Commission concluded that consideration should be given to whether it was viable for aeronautical applications to make direct use of IPS in the aeronautical environment and gave the Aeronautical Communications Panel (ACP) Working Group N (Networking) the task to, “consider the use of TCP/IP protocols in the provision of aeronautical internetworking”. ACP Working Group N produced an initial report which was presented at the June 2005 ACP Working Group of the Whole Meeting. The report concluded that use of the IPS in the ground environment appeared to be straightforward and further consideration was to be given with the aim of development of a minimum set of SARPs and Guidance Material necessary to support global interoperability. However for air-ground communications the report noted that technical issues, mainly related to mobility and security aspects associated with the introduction of the IPS in air-ground data link systems, need to be resolved. This report presents an initial analysis of a number of candidate ATN IPS mobility solutions.
A set of candidate solutions was identified at the November Sub-Group N1 meeting held in Montreal in November 2005. The candidate solutions identified were in several areas and included: using IETF mobile networking approaches, applying IETF Inter-domain routing protocols or adapting ISO Inter-domain routing protocols, performing mobility at the transport layer, and performing mobility at the application layer. The candidate approaches are listed in Table ES-1
Table ES-1 Candidate Approaches
During the November 2005 meeting Sub-Group N1 also identified a set of Technical and Implementation Characteristics which are used for analysis of each candidate approach. Note that the characteristics have not been identified to select a particular approach but rather to determine if IPS mobility is feasible generally to support the needs of the aviation community.
The IETF approaches to mobility Mobile IPv6 and NEMO appear to hold promise for the long term. However, it should be clear that the extensions to MIPv6 and NEMO are still evolving.
An inter-domain routing approach on its own, using BGP, would undoubtedly work, since the current network uses a similar protocol, but concerns centre on the degree of manual configuration required and its responsiveness following network mobility events.
IDRP would also work; however, the community would still be left with an aviation-specific solution.
OSPF applied on a single routing domain perspective could be employed to alleviate the convergence issues but there may be administrative issues since it is expected that the ATN will be operated by multiple service providers and administrations.
SCTP is a standard that was not designed for mobility. Many instances of experimentation have demonstrated that SCTP is capable of supporting mobility, and even has some desirable features not found in network-layer solutions, but this type of use is not directly supported by the standards documents or available vendor implementations.
Neither of the two Instant Messaging approaches: XMPP and SIMPLE is directly designed to provide the type of smooth mobility that is under consideration here, although they could be used to provide an ACARS-like service.
An ATN application based approach to mobility has the advantage of a simplified network layer; however, it does not take advantage of COTS solutions.
This report concludes that mobility in an IPS environment is feasible. Candidate approaches have their individual strengths in each of the characteristics identified.
TABLE OF CONTENTS
1. Background 8
2. Introduction 10
2.1 Summary of Candidate Approaches for IPS Mobility 10
2.2 Technical Implementation Characteristics of Candidate Approaches for IPS Mobility 10
2.2.1 Technical Characteristics 10
2.2.2 Implementation Characteristics 11
3. Detailed Analysis 12
3.1 Approach N1 – Mobile IPv6 (MIPv6) 12
3.1.1 Approach N1 Description 12
22.214.171.124 Basic Provisions of MIPv6 12
126.96.36.199 Extensions to MIPv6 14
188.8.131.52.1 Mobile Nodes And Multiple Interfaces in IPv6 (MONAMI6) 14
184.108.40.206.2 Fast Handovers for Mobile IPv6 (FMIPv6) 17
220.127.116.11.3 Heirarchical Mobile IPv6 (HMIPv6) 17
18.104.22.168.4 Security Extensions to Mobile IPv6 18
22.214.171.124.4.1 Mobile Node-Home Agent Protection Extensions 18
126.96.36.199.4.2 Mobile Node-Correspondent Node Protection Extensions 20
3.1.2 Approach N1 Analysis 20
188.8.131.52 TC1 - Support Authorized Traffic Type and Category 20