<p> Brussels, 27-29 June 2006</p><p>AERONAUTICAL COMMUNICATIONS PANEL(ACP) WORKING GROUP N - NETWORKING SUBGROUP N3 – GROUND-GROUND APPLICATIONS </p><p>SITA DOMAIN and AMHS/TYPE B GATEWAY ADDRESSING SCHEME </p><p>(Presented by SITA)</p><p>1 INTRODUCTION SITA has been operating an AFTN/TYPE B gateway for over 40 years. The service is today connected via low-level circuits to the AFTN network in some 40 countries. These inter-connections allow ATS organizations and airlines to communicate using AFTN messages on ATS organizations’ side and TYPE B messages on the airlines’ side. The SITA service provides all the necessary conversions for transparent communications. Currently around 21,000 messages from AFTN to TYPE B and 11,000 messages from TYPE B to AFTN are exchanged on a daily basis. Further to the planned AFTN replacement by AMHS, a new communication path must be implemented between ATS Organizations, which will use AMHS, and airlines. The aim of this paper is to propose an AMHS addressing scheme for the TYPE B users. 2 Background SITA is operating a worldwide X.400 ADMD and a TYPE B /X.400 gateway since 1989. SITA Domain Name is C=WW / A=SITAMAIL and TYPE B users are identified in X.400 world with an O/R Name of the form: C=WW/A=SITAMAIL/O=TYPEB/S=typeb_address. 3 Proposal In order to ensure that communications between airlines and ATS Organizations will take full advantage from AMHS implementation, SITA plans to provide a direct TYPE B/AMHS conversion service. In this respect, TYPE B users must be identified from the AMHS world. The two following schemes can be proposed for that purpose:  C=WW/A=SITAMAIL/O= TYPEB/S=’typebadd’  C=WW/A=SITAMAIL/O= AFTN/S=’aftnadd’</p><p>Where ’typebadd’ is the TYPE B address of the TYPE B user and ‘aftnadd’ is the AFTN address associated with this TYPE B address. 1/2 4 Conclusion SITA would like to get:  Comments and recommendation on the proposed addressing schemes  Advice on the procedure to be applied to get the addressing scheme registered by ICAO</p><p>2/2</p>