j.onions@xtel.co.uk (Julian Onions) (03/01/91)
> X.{4,5}00 names for people & mailboxes have (at least) the following attri bu > tes: > > Country /C=../ > Administrative Domain /ADMD=.../ > Primary Domain /PRMD=.../ > Organization /O=.../ > Organizational Unit /OU=.../ > Surname /S=.../ > Given Name /G=.../ > Common Name /CN=.../ No - you are missing something here. X.400 and X.500 are different. X.400 was designed before X.500 and therefore X.400 could not rely on X.500 information. This is why X.400 includes obvious routing things such as ADMD and PRMD. An X.500 Distinguished Name has almost no constraints on it whatsoever. In practice, it usual starts with a Country, Orgnization or locality as the most significant part, but this is not enforced by the standard. X.500 is used to look up X.400 names so my X.500 DN may be very different to my X.400 mail address and you can't in general algorithmically derive one from another. The X.500 name is meant to be natural and 'intuitive' the X.400 address is meant as an address. As it looks so horrible - you are meant to try and hide it from the users wherever possible (my opinion). Just to complete this an example: My Distinguished Directory Name is the following (in white pages syntax) C=GB@O=X-Tel Services Ltd@cn=Julian Onions my X.400 address on the other hand is (in rfc987 syntax) /C=GB/ADMD= /PRMD=X-Tel Services Ltd/O=Xtel/I=J/S=Onions/ X.400 in the 1984 recommendation says an address is made up of the following components. Country, ADMD, PRMD, X121address, TerminalID, Organization, UniqueUAID, Personal Name (made up of initial, given, surname and generational-qualifier) organizationalunit and domaindefined-attributes X.400 only allows one of 5 combinations of these though. X121address & terminalID (optional) - used for sending mail when - you're infrastructure only - supports digits (e.g. - phone/telex) C, ADMD, UniqueUAId & DD (optional) C, ADMD, X121address & DD (optional) C, ADMD, + one or more of { PRMD, PN, O, OU, DD } In practice, it is only the last one that I have ever seen used. The other cases I think are for a PTT running a service and supplying a mailbox facility or some such. In the 1988 X.400 standard a whole bunch of new attributes were added. There are one or two extensions, such as CommonName for things that are and aren't people (seems kind of silly to address a list as 'Surname=tcp-ip'). The rest are broadly speaking either Teletex string forms of the above, so that you can type names in whatever alphabet you require, or paper postal address attributes to allow interworking between X.400 and the postal system. > Are these attributes required of every X.[45]00 people and mailbox > names, or are they specific to the naming convention chosen by the > NYSERNet White Pages Project (and possibly others)? Summary: X.400 is fairly rigid in the addresses you can have, X.500 isn't. The white pages project has a lot of freedom to choose formats, X.400 people don't have so much. (In practice, you don't get so much freedom in X.500 - you are dependant on what the higher parts of the tree define. For E.G. if C=US decided that at the next layer down people are either put into subtrees type=competent and type=incompetent you are stuck with this if you want to join the tree :-) ...) Julian.