Aviation application over IPv6: performance issues

Aviation industries in United States and in Europe are undergoing a major paradigm shift in the introduction of new network technologies. In the US, NASA is also actively investigating the feasibility of IPv6 based networks for the aviation needs of the United States. In Europe, the Eurocontrol lead, Internet protocol for aviation exchange (iPAX) Working Group is actively investigating the various ways of migrating the aviation authorities backbone infrastructure from X.25 based networks to an IPv6 based network. For the last 15 years, the global aviation community has pursued the development and implementation of an industry-specific set of communications standards known as the aeronautical telecommunications network (ATN). These standards are now beginning to affect the emerging military global air traffic management (GATM) community as well as the commercial air transport community. Efforts are continuing to gain a full understanding of the differences and similarities between ATN and Internet architectures as related to communications, navigation, and surveillance (CNS) infrastructure choices. This research paper describes the implementation of the IPv6 testbed at Computer Networks & Software, Inc. and it´s interface connection mechanism to Eurocontrol and NASA´s (Cleveland) testbed in the first phase of the project. In the second phase this research work investigates the performance issues of aviation applications such as controller to pilot data link communication (CPDLC), on an IPv6 based backbone network. Aviation applications are grouped into different priority levels. Desired quality of service (QoS) to each priority level is implemented via Diffserv implementation. This research work looks into the possibility of providing similar QoS performance for aviation application in an IPv6 network as is provided in an ATN based network. The testbed consists of three autonomous systems. The autonomous system represents CNS domain, NASA domain and a EUROCONTROL domain. The primary mode of connection between CNS IPv6 testbed and NASA and EUROCONTROL IPv6 testbed is initially a set of IPv6 over IPv4 tunnels. The aviation application under test (CPDLC) consists of two processes running on different IPv6 enabled machines. These processes communicate with each- other over the IPv6 network. One machine resides on the CNS portion of the testbed and other may reside in NASA (Cleveland) and/or in Eurocontrol. The IPv6 packets between Eurocontrol, NASA and CNS testbeds would be carried on IPv6 over IPv4 tunnels. We present some results, which suggest that IPv6 QoS has matured enough, so as to provide the QoS service, which is similar in capability to die ATN architecture. We implemented three basic priorities of flow: (1) command & control; (2) surveillance; and (3) general traffic. Various parameters like throughput, packet loss and delay are investigated. The results are analyzed to get a conceptual view of the effect of IPv6 based network on the aviation applications.