AMHS(ATS Message Handling System)

Presented by

Hoang Tran

U.S. FAA/AOS-900

Presentation ATN2.4-Part Presentation ATN2.4-Part BB

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 ATNDeliver a level of service at least equivalent to the that of the AFTNAllow transition from AFTN to ATNAMHS users to/from AMHS usersAMHS users to/from AFTN usersAFTN 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 fieldsAdds user authentication (security)Adds use of ATN Directory ServiceDefines system management requirementsDefines 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) 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 submissionMessage forwardingMessage Delivery

ATN AMHS MTA

ATN AMHS MTA specific functionsLimited body part types

1 IA5 (text) message partLimited message formats

Defines an AFTN-like message formatLogging of messages

Satisfies long-term retention requirements of ICAO Annex 10

AFTN/AMHS GatewayDefines 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

Ground Domain

AFTN

AFTN/AMHS Gateway

AFTNStation

BISAFTN

AFTN stationAFTN/AMHSGateway

AMHSMTA & UA

Ground Domain

AFTN Message AMHS Message

AMH

S M

essage BIS

AFTN Message

AMHSMTA & UA

IS

D

AFTN User-to-AFTN User

A

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

AMHS Implements ICAO Doc. 9705 ed. 2:

MTA based on Asia/Pac AMHS ICDAFTN/AMHS Gateway based on Asia/Pac ICDProprietary UAProprietary Control PositionX.25 interfaces to AFTNLAN interfaces to ATN router

AMHS Product Description (2)

AMHS UAbased on JAVA technologyaccess to remote Message Transfer Agent

(MTA) allows for both AFTN over X.400 and

X.400 message generationprovided with customization if required

AMHS Product Architecture

HardwareMTA

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)

Softwareall software written in C except UA file based for reliability

AMHS Product Architecture (3)

ATN

R

LAN

MTA

TCP/IP/CLNP

FAA

Control PositionX.25

Window X.25

AFTN

UA

MTA and Control Position

Flow control implements priority mechanisms for

processing messagesall processing is file based

Loss of X.25 files stored at control position until error

clearedMTA 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 backgroundcreation of CD-ROM of log files

Statisticsbasic gathering of statistics and log

informationdatabase recording of statistics

MTA and Control Position

MTA has no HMI - all through the control position

Control Position - window basedediting of messages with errorscontrol of the MTA

User Agent (UA)

JAVA-based HMIBoth AFTN over X.400 and X.400 message

creation screens

Storage of all received/read messagesSorted by selected fieldsAddress management with lists and

address book

Generation of probes

Demonstration System

MTA2

MTA1

Control Position

UA

AFTN Terminal

THANK YOU

Any Questions?