​Welcome to the preliminary AMHS MD register

This area allows you to either browse the complete AMHS management domains (MD) and addressing information register or to search the database for specific entries.


Browse the preliminary AMHS MD register

Browse the AMHS MD register. Browser CAAS table.

You may also generate an Excel file of the complete register by clicking AMHS MD register and CAAS table.

Search the preliminary AMHS MD register

Search the AMHS MD register.


AMHS uses X.400 addressing.
The basic addressing structure in X.400 is know as the O/R Name (Originator/Recipient Name). An O/R Name is composed of two elements, of which at least one must always be present:
An O/R Address.

This is a structured address, supported by all X.400 systems.
Directory Name.

This is the name of an entry in an X.500 directory, which represents the end user. The O/R address is structured in attribute value pairs, which supports message routing without directory and enables high flexibility in addressing structure and approach. AMHS allows any O/R address to be used, but for early deployments it is anticipated that most addresses will follow one of two specific forms, know as "XF" and "CAAS". Examples O/R Addresses:


It can be seen that these O/R Addresses bear some relationship to AFTN addresses, but not a simple algorithmic one.

Directory names are also attribute structured and are hierarchical, typically following a "Country, Organization, Common Name" hierarchy. For example:
  • Country=FR, Organization=LFCI, Common Name=LFCIZPZX
  • Country=FR, Organization=LFCI, Common Name=Operator

This structure is easier to understand than the O/R Address (because it does not need to include routing information) and can use values which are intuitive.

Further information can be obtained from [TBD].


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