Transcript Slide 1

Federal Aviation
Administration
Technical Operations Services
AMHS/AFTN Routing in a
Global Network
Topics
• As more AMHS systems become operational, we need to better
manage the Global AMHS/AFTN routing network.
• These items must be considered for future AMHS connectivity :
• AMHS Management Domain repositories.
• Use of CAAS/XF Addressing scheme.
• Interoperability testing between all MTAs connected to the US would
be the ideal scenario. However, it is mandatory to have connectivity
testing between multiple MTAs that terminate at a single US MTA.
General Information-AMHS Management
Domains
• The AMHS Address or AMHS O/R (Originator/Recipient)
Address is the way in which MTAs (Message Transfer
Agents) route messages. MTAs are a component of an
AMHS/AFTN Gateway.
• An MTA is usually configured to route based on the
AMHS Management Domain portion of the AMHS
Address. This is comprised of the Country (C),
Administrative Domain (ADMD or A), and the Private
Domain (PRMD or P) attributes. Historically, the private
domain attribute was reserved for the ICAO Nationality
Letter assigned in Doc 7910. This guarantees :
– an AFTN to AMHS address mapping for all AFTN addresses.
– an AMHS route for all AFTN addresses.
– a unique route for each ICAO nationality.
General Info Examples-AMHS Management
Domains
• For example,Japan AMHS will accept messages for the following
AMHS Management Domains:
C=XX, A=ICAO, P=RJ -Japan
C=XX, A=ICAO, P=UA - Kazakhstan
C=XX, A=ICAO, P=VA - India
• For example, Peru AMHS might accept messages for the following
AMHS Management Domains:
C=XX, A=ICAO, P=SP - Peru
C=XX, A=ICAO, P=SL - Bolivia
C=XX, A=ICAO, P=SC – Chile
• For example, UK AMHS might accept messages for the following
AMHS Management Domains:
C=XX, A=ICAO, P=EG - UK
C=XX, A=ICAO, P=ED - Germany
Interoperability Issues-AMHS Management
Domains
• Since routing is done on AMHS Management Domains, all
AMHS/AFTN gateways must use the same AMHS Management
Domain repository.
• Japan and the US relied on a working paper, PRMD (Management
Domain)_for_theUS-Japan_AMHS_service_B.doc
• There is an ICAO web site http://www.icao.int/anb/panels/acp/amhs/AMHSRegisterLis
t.cfm
• Eurocontrol's OneSky Online website, which is accessed and
managed though the AMC application
CAAS scheme : Overview
•
•
•
•
•
•
An AMHS address built using the CAAS address scheme
might look something like this:
C=XX, A=ICAO, P=GERMANY, O=EDDD, OU1= EDZZ ,
CN= EDZZXXXX (=8 char AFTN Address )
C=XX, A=ICAO, P=GERMANY is the global domain identifier
or AMHS Management Domain.
O (Organization) attribute represents a geographical
location.
OU1 (Organizational Unit 1) represents a 4 character ICAO
location identifier- 1st 4 characters of the AFTN Address.
CN (Common Name) represents the 8 character ICAO
address.
XF scheme: Overview
• That same address built using the XF addressing scheme
would look like this:
• C=XX, A=ICAO, P=GERMANY, O=AFTN,
OU1= EDZZXXXX.
• C=XX, A=ICAO, P=GERMANY is the global domain identifier
or AMHS Management Domain.
• O (Organization) =AFTN is a fixed field used by all
AMHS/AFTN gateways.
• OU (Organizational Unit) represents the 8 character ICAO
address.
General Information-AMHS Addressing
Scheme
• We are using a local ATN Directory as a repository for the
AMHS Management Domains and for address mapping
between the AFTN and AMHS O/R addresses. We use the
ATN schema defined in SARPs ATN Directory Services (DIR)
– Sub volume Seven, Third Edition. We have extended the
atn-AmhsMD schema to include an atn-Amhs-addr-scheme,
indicating the countries scheme of choice, XF or CAAS. The
address mapping is based on this attribute.
General Information-AMHS Addressing
Scheme
• Each ICAO country may declare their choice of addressing
scheme for mapping addresses within their Management
Domains.
• An accurate representation of this should be in the same
repository as the AMHS Management Domains.
• All AMHS/AFTN Gateways should be capable of mapping an
AFTN address to either scheme.
General Info Examples-AMHS Addressing
scheme
• Mapping an AFTN address , EDZZXXXX. If the entry for the ICAO
country code, ED ( matching the first two characters of the AFTN
address), were marked as CAAS addressing scheme. The AMHS
address would look like this : C=XX, A=ICAO, P=GERMANY,
O=EDDD, OU1= EDZZ , CN= EDZZXXXX.
• If the entry for the ICAO country code, ED, were marked as XF
addressing scheme. The AMHS address would look like this :
C=XX, A=ICAO, P=GERMANY, O=AFTN, OU1=
EDZZXXXX.
Interoperability Issues-Addressing Scheme
• Since there are 2 ‘standard’ AMHS addressing schemes, all
AMHS/AFTN Getways should be using the same repository for the
address scheme of each AMHS Management domain.
• In our operational system in Salt Lake City, it is necessary
to mark all of the AMHS Management Domains as using XF
addressing. At the time of implementation, Japan was/is
only capable of mapping AFTN/AMHS addresses using the
XF addressing scheme.
• The UK has stated that they will only be using the XF addressing
scheme.
Legacy Questions-Addressing scheme
• Why are countries declaring the use of CAAS addressing, when the
AMHS/Gateway fronting for these countries only use the XF
addressing scheme ?
• Example – ICAO country code , UU, declares CAAS. These
messages transit the Japan AMHS. Japan AMHS is only capable of
mapping XF addresses ??
General Information-Multiple MTAs
connected to a single US MTA
• The AMHS/AFTN Gateway is comprised of 3 components. The
MTA, the MTCU, and AFTN components.
• MTA routing is configured separately from the AMHS/Gateway and
AFTN applications.
Examples-Multiple MTAs connected to the
US MTA- Atlanta(ATN Network diagram)
• Routing Rules for the MTA in Atlanta, assuming UK and Peru MTAs:
• Peru MTA would accept messages for the following AMHS
Management Domains:
C=XX, A=ICAO, P=SP - Peru
C=XX, A=ICAO, P=SL - Bolivia
• Consider a message from the UK with a recipient in Bolivia (C=XX,
A=ICAO, P=SL,O=AFTN,OU1=SLYYYFYX), and the edit
position at ATL (C=XX, A=ICAO, P=K, O=AFTN,
OU1=KATLEDIT). In the current configuration, the US MTA in
Atlanta accepts the message and begin it’s routing algorithm. The
recipient for Bolivia would get sent to the MTA in Peru, while the US
delivery would go to the AMHSGate application and further to US
AFTN.
Interoperability-Multiple MTAs connected to the US
MTA- Atlanta.
• In the previous example, the message ‘payload’ or P2
portion of the message was created by the UK MTA. The
US MTA would not alter this portion of the message.
• The US MTA would rebuild the part of the message that the
MTAs use or P1 portion of the message.
• In order to insure seamless operations, connectivity testing should
be done between all MTAs connected to a single US MTA.
Summary
•
•
•
•
These items must be considered for future AMHS connectivity:
AMHS Management Domain repositories.
Use of CAAS/XF Addressing scheme.
Interoperability among all operational MTAs.