There are several apparent differences:
The greatest degree of negotiating clout will lie with users who generate large traffic volumes and can migrate to other suppliers, or who can install their own equipmentThe ADMD name is a bar to migrating to another supplier; the routing habit is a bar to "installing your own equipment" - that is, PRMDs cross-connecting to other PRMDs or ADMDs. In some countries, it's even illegal....
There are also some important commonalities:
Attribute Type Abbreviation Label (where necessary) Given Name Given name G Initial Initials I Surname Surname S Generation Qualifier Generation Q Common Name Common Name CN Organization Organization O Organizational Unit 1 Org.Unit.1 OU1 Organizational Unit 2 Org.Unit.2 OU2 Organizational Unit 3 Org.Unit.3 OU3 Organizational Unit 4 Org.Unit.4 OU4 Private Management Domain Name PRMD P Administration Management Domain Name ADMD A Country Country C Physical Delivery Personal Name PD-person PD-PN Extension of Postal O/R Address Components PD-ext.address PD-EA Extension of Physical Delivery Address Components PD-ext.delivery PD-ED Physical Delivery Office Number PD-office number PD-OFN Physical Delivery Office Name PD-office PD-OF Physical Delivery Organization Name PD-organization PD-O Street Address PD-street PD-S Unformatted Postal Address PD-address PD-A1 PD-A2 (there are individual labels for PD-A3 each line of the address) PD-A4 PD-A5 PD-A6 Unique Postal Name PD-unique PD-U Local Postal Attributes PD-local PD-L Postal Restante Address PD-restante PD-R Post Office Box Address PD-box PD-B Postal Code PD-code PD-PC Physical Delivery Service Name PD-service PD-SN Physical Delivery Country Name PD-country PD-C X.121 Network Address X.121 X.121 E.163/E.164 Network Address ISDN ISDN PSAP Network Address PSAP PSAP User Agent Numeric ID N-ID N-ID Terminal Identifier T-ID T-ID Terminal Type T-TY T-TY Domain Defined Attribute DDA:Most of these aren't used very much; those with PD- in front of them are used with X.400 networks that support delivery of mail by printing it onto paper and sending it to the postal service, and the only one I've seen used out of the network crowd is the X.121, which some ADMDs use to address fax machines through the telephone network.
DDA: where the notation identifies the type of domain defined attribute.
[soap....] I regard attribute-based addressing as a mistake.
This stems from the fact that attribte labels tend to make people believe that the named entity should have some property associated with the label; for instance, they expect something to be an organization just because it is named in the "organization" field, and something "should be" a person just because it has a "surname" field.
They also expect address hierarchies to conform to organizational charts, thinking that OU1=trondheim; OU2=sales means that there is a Trondheim office controlling the Trondheim sales department. (Trondheim is a city), or expect an user to work for an organization just because he uses its O field, while he is in fact a customer of their service. [....soap]
Other problems include the use of "country": SITA, the airline industry network, has unilaterally started to use "C=WW" for "world wide", because several of its customers refused to be locked into a statement about which country they were located in, and the ISODE Consortium, with offices in the UK and USA, uses "C=FI" because their service provider happens to be operating out of Finland.
It added an extension mechanism, allowed most attributes to be written using the Teletex charset (Japanese characters, and most accents, but NOT greek, Arabic or Sanskrit), and then added the proviso that you had to make all the mailboxes addressable using the older PrintableString attributes, because you couldn't expect everyone in the world to be fluent Kanji typists.
It also added the "Common Name", "because it seems so silly to talk about the surname of a process or mailing list", adding further to the confusion, and not helping ease of mapping at all.
There have been moves afoot to add the possibility of putting Internet-style addresses into X.400 addresses as a new attribute, making life easier for the Internet gateways, but rather harder for those whose UAs haven't even found out what a Common Name is yet.
Another interesting twist is the "special ADMD values", SPACE for
indicating "You may route on the C,PRMD tuple, and if you are
connected to any ADMD in the country, you can expect it to be
delivered", which works with at least some UK ADMDs, and the zero ("0")
for indicating that you are in a PRMD that is connected to no ADMD, so
if you don't have a route directly to it, you can drop the message
The latter one hasn't exactly been a raging success...
SOME_USER@HP-SWITZERLAND-desk1////////HPMEXT1/THIERRY#b#PARIDANT#o#HP8700#o#Y0.om.hp.com (current leader in category "abusive domain name". Apparently worked!) GIS_+a_RCI_+lGivenname_Surname+i%MHS+d_20D08E2B01F53FDC-20D08E2B02F53FDC%RCI_Incorporated@mcimail.com (current leader in category "abusive user naming"; it couldn't be replied to either) John_Smith%Dept_Server%Widget_Dept@company.gateway.com (rabid rewriters may think they know what a percent sign is for) (produced by Banyan Vines gateways; I don't have a working example) firstname.lastname@example.org (most cryptic address format in widespread use)Common to most of these are: