This specification is based on IETF Request for Comments (RFC). Applicable RFCs used in this specification are listed in Section 1.4. Except where necessary, information already contained in any RFC is not duplicated within this specification, and it is recommended that the reader obtain a copy of the applicable RFC when necessary.

This specification defines the broad characteristics of two types of networks:

1. Compliant Aircraft Data Network, referred to as Compliant Network.

2. Profiled Aircraft Data Network, referred to as Profiled Network.

In summary, a Compliant Aircraft Data Network operates fully within the applicable Internet specifications as defined in the relevant IETF RFCs. A Profiled Aircraft Data Network is one in which one or more industry standard protocols have been extended to address unique problems of the avionics industry.

Interoperability between a Compliant Network and a Profiled Network, or between Profiled Network systems with different characteristics, is not assured without the use of an intermediate system, such as a router or gateway. In addition, a Profiled Network may provide some characteristics typical of a Compliant Network to a User Application (UA); but the fundamental or underlying behavior of the network may not be identical.

Purpose of Document

This document specifies a profile of Internet Engineering Task Force (IETF) standard protocols and services for use on board aircraft. It is the intent of this specification to define the functionality of standard Internet protocols and services in a manner that allows interoperability of components connected to onboard data networks while simultaneously being totally independent of functionality. Not all functions of a "standard" Commercial Off the Shelf (COTS) implementation may be useful, or appropriate, for all onboard networks. However, by implementing a "proper subset" of Internet standards the goal of maximum interoperability balanced with cost of implementation and certification can be achieved.