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

2. 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 Ed. 2)
ATS Extended Service (Doc Ed. 3)
AFTN/AMHS Gateway (Doc Ed. 2)

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

4. 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

5. 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

6. AMHS Extended Service
Most recently defined enhancements to AMHS (Doc 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

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

8. 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

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

10. 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

11. 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

12. 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

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

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

15. AMHS Product Descriptions
Implements ICAO Doc 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

16. 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

17. 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

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

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

20. 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

21. 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

22. 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

23. 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

24. 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

25. Demonstration System UA
MTA1
MTA2
AFTN Terminal
Control Position

26. THANK YOU
Any Questions?