scope:

GENERAL OVERVIEW 

This manual contains the minimum communication standards and protocols that will enable implementation of an ICAO aeronautical telecommunication network (ATN) based on the Internet protocol suite (IPS), referred to as the ATN/IPS. The scope of this manual is on interoperability across administrative domains. This includes administrative domains participating in the global ATN/IPS internetwork as well as administrative domains directly connected via point-to-point connections. Implementation of the ATN/IPS, including the standards and protocols included in this manual, will take place on the basis of regional air navigation agreements between ICAO Contracting States in accordance with Annex 10, Volume III, Part I, Chapter 3, 3.3.2. Planning and Implementation Regional Groups (PIRGs) coordinate such agreements.

The ATN/IPS protocol architecture is illustrated in Figure I-1-1. The ATN/IPS has adopted the same fourlayer model as defined in Internet Society (ISOC) Internet standard STD003. Note.- STD003 is a combination of Internet Engineering Task Force (IETF) RFC 1122 and RFC 1123. 

This model has four abstraction layers called the link layer, the Internet or Internet protocol (IP) layer, the transport layer and the application layer.

As depicted in Figure I-1-1, this manual does not adopt any specific link layer protocol as this is a local or bilateral issue which does not affect overall interoperability.

This manual adopts the Internet protocol version 6 (IPv6) for Internet layer interoperability. Implementation of IPv4 in ground networks, for transition to IPv6 (or as a permanent network) is not addressed in this manual. IPv6 is to be implemented in air-ground networks. The border gateway protocol - 4 (BGP-4) with extensions is adopted for interdomain routing.

The transmission control protocol (TCP) and user datagram protocol (UDP) are adopted for connectionoriented and connectionless services at the transport layer.