AMHS (ATS Message Handling System) Presentation ATN2.4-Part B AMHS (ATS Message Handling System) Presented by Hoang Tran U.S. FAA/AOS-900

AMHS Definition Provides a ATN-specific messaging system Similar to AFTN and can interoperate with it Based on ITU-T X.400 standards Three main classes of service ATS Basic Service (Doc. 9705 Ed. 2) ATS Extended Service (Doc. 9705 Ed. 3) AFTN/AMHS Gateway (Doc. 9705 Ed. 2)

AMHS in the ATN AMHS first ground-ground ATN application defined Doc. 9705 Sub-Volume 3 contains definition

AMHS Requirements Provide a messaging service over the ATN Deliver a level of service at least equivalent to the that of the AFTN Allow transition from AFTN to ATN AMHS users to/from AMHS users AMHS users to/from AFTN users AFTN users to/from AFTN users via ATN

AMHS Basic Service Original AMHS Specification Adapted to Aeronautical Environment, especially AFTN Functionality Defines very limited format (AFTN-like) Restricts X.400 capabilities to limited subset (messages consist of single IA5 body-part) Maps AFTN service elements to fields in message text

AMHS Extended Service Most recently defined enhancements to AMHS (Doc. 9705 Ed. 3) Extends the number and types of body-parts (i.e., message contents) Specifies a mapping of message elements to standard X.400 fields Adds user authentication (security) Adds use of ATN Directory Service Defines system management requirements Defines a CIDIN Gateway

AFTN/AMHS Gateway Allows Transition from AFTN to ATN Defines interoperability between AFTN systems and AMHS Defines mappings between AFTN services and AMHS services

AMHS Components Message Transfer Agents (MTAs) User Agents (UAs) Provides the message transfer and delivery functions User Agents (UAs) Provides end-user message sending and reading Mostly defined by implementation rather than SARPs Control Position ATN specific management station AFTN/AMHS Gateway Provides interoperability between AFTN users and AMHS users

AMHS MTA Implements X.400 messaging functions: Message submission Message forwarding Message Delivery

ATN AMHS MTA ATN AMHS MTA specific functions Limited body part types 1 IA5 (text) message part Limited message formats Defines an AFTN-like message format Logging of messages Satisfies long-term retention requirements of ICAO Annex 10

AFTN/AMHS Gateway Defines a Message Transfer and Control Unit (MTCU) Maps between AFTN messages and AMHS messages Processes AFTN service messages Maps between AFTN and AMHS priorities Defines Control Position functions Display of errors Interface for correction of errors in AFTN messages Defines an AFTN component Behaves like an AFTN center Responds to AFTN service messages that do not generate AMHS message

AFTN User-to-AFTN User Ground Domain AFTN AFTN/AMHS Gateway Station BIS station AFTN/ AMHS MTA & UA AFTN Message AMHS Message A IS D

by Hoang Tran US FAA/AOS 900 FAA ATN AMHS by Hoang Tran US FAA/AOS 900

ATN Program Overview FAA has developed the following ATN Products: AMHS with integrated AFTN/AMHS gateway AMHS User Agents

AMHS Product Descriptions Implements ICAO Doc. 9705 ed. 2: MTA based on Asia/Pac AMHS ICD AFTN/AMHS Gateway based on Asia/Pac ICD Proprietary UA Proprietary Control Position X.25 interfaces to AFTN LAN interfaces to ATN router

AMHS Product Description (2) AMHS UA based on JAVA technology access to remote Message Transfer Agent (MTA) allows for both AFTN over X.400 and X.400 message generation provided with customization if required

AMHS Product Architecture Hardware MTA either single workstation or dual/redundant workstation with automatic switch-over NetBSD Control Position/X.25 interface PC (Windows) UAs any network capable computer

AMHS Product Architecture (2) Software all software written in C except UA file based for reliability

AMHS Product Architecture (3) FAA Control Position MTA X.25 AFTN Window X.25 LAN TCP/IP/ CLNP ATN R UA

MTA and Control Position Flow control implements priority mechanisms for processing messages all processing is file based Loss of X.25 files stored at control position until error cleared MTA message processing continues during X.25 errors

MTA and Control Position (2) X.25 Status Monitoring card monitor circuit monitor Probes and Non-Delivery Reports (NDR) NDRs generated and received by MTA sent to control position database of AFTN and AMHS messages for NDR correlation Probes supported

MTA and Control Position Scripts for log file maintenance run in background creation of CD-ROM of log files Statistics basic gathering of statistics and log information database recording of statistics

MTA and Control Position MTA has no HMI - all through the control position Control Position - window based editing of messages with errors control of the MTA

User Agent (UA) JAVA-based HMI Storage of all received/read messages Both AFTN over X.400 and X.400 message creation screens Storage of all received/read messages Sorted by selected fields Address management with lists and address book Generation of probes

Demonstration System UA MTA1 MTA2 AFTN Terminal Control Position

THANK YOU Any Questions?