RFC2294: Representing the O/R Address hierarchy in the X.500 Directory Information Tree
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Obsoletes:
RFC1836
Network Working Group S. Kille
Request for Comments: 2294 Isode Ltd.
Obsoletes: 1836 March 1998
Category: Standards Track
Representing the O/R Address hierarchy in the
X.500 Directory Information Tree
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
Abstract
This document defines a representation of the O/R Address hierarchy
in the Directory Information Tree [6, 1]. This is useful for a range
of purposes, including:
o Support for MHS Routing [4].
o Support for X.400/RFC 822 address mappings [2, 5].
Please send comments to the author or to the discussion group <mhs-
ds@mercury.udev.cdc.com>.
Kille Standards Track [Page 1]
RFC 2294 Directory Information Tree March 1998
Object Class Mandatory
------------ ---------
mHSCountry M
aDMD M
pRMD O
mHSX121 O
mHSNumericUserIdentifier O
mHSOrganization O
mHSOrganizationalUnit O
mHSPerson O
mHSNamedObject O
mHSTerminalID O
mHSDomainDefinedAttribute O
Table 1: Order of O/R Address Directory Components
1 The O/R Address Hierarchy
An O/R Address hierarchy is represented in the X.500 directory by
associating directory name components with O/R Address components.
An example of this is given in Figure 1. The object classes and
attributes required to support this representation are defined in
Figure 2. The schema, which defines the hierarchy in which these
objects are represented in the directory information tree is
specified in Table 1. A given object class defined in the table will
always be higher in the DIT than an object class defined lower down
the table. Valid combinations of O/R Address components are defined
in X.400.
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RFC 2294 Directory Information Tree March 1998
/\
/ \
C=GB / \ Numeric-C=234
/ \
/ \
/ \
+------------+<----------------+----+
| Country | | |
+------------+ +----+
/\
/ \
/ \
/ \
ADMD=" " / \ ADMD=Gold 400
+-------------+ +------------+
| ADMD | | ADMD |
+-------------+ +------------+
\ \
\ \
\ PRMD=UK.AC \ PRMD=UK.AC
\ \
+----------+ +----+
| PRMD |< -----------| |
+----------+ +----+
/
/
O=UCL
/
/
+------------+
| MHS-Org |
+------------+
\
\ OU=CS
\
\
+-----------+
| MHS-OU |
+-----------+
Figure 1: Example O/R Address Tree
Kille Standards Track [Page 3]
RFC 2294 Directory Information Tree March 1998
IMPORTS
ub-domain-name-length, ub-organization-name-length,
ub-organizational-unit-name-length, ub-common-name-length,
ub-x121-address-length, ub-domain-defined-attribute-type-length,
ub-domain-defined-attribute-value-length, ub-terminal-id-length,
ub-numeric-user-id-length, ub-country-name-numeric-length,
ub-surname-length, ub-given-name-length, ub-initials-length,
ub-generation-qualifier-length
FROM MTSUpperBounds {joint-iso-ccitt mhs-motis(6) mts(3) 10
modules(0) upper-bounds(3) };
mHSCountry OBJECT-CLASS ::= {
SUBCLASS OF {country}
MAY CONTAIN {mHSNumericCountryName}
ID oc-mhs-country}
mHSNumericCountryName ATTRIBUTE ::= {
WITH SYNTAX NumericString (SIZE (1..ub-country-name-numeric-length))
SINGLE VALUE 20
ID at-mhs-numeric-country-name}
aDMD OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {aDMDName}
ID oc-admd}
aDMDName ATTRIBUTE ::= {
SUBTYPE OF name
WITH SYNTAX DirectoryString {ub-domain-name-length} 30
ID at-admd-name}
pRMD OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {pRMDName}
ID oc-prmd}
pRMDName ATTRIBUTE ::= {
SUBTYPE OF name
WITH SYNTAX DirectoryString {ub-domain-name-length} 40
ID at-prmd-name}
mHSOrganization OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {mHSOrganizationName }
ID oc-mhs-organization}
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mHSOrganizationName ATTRIBUTE ::= {
SUBTYPE OF organizationName
WITH SYNTAX DirectoryString {ub-organization-name-length} 50
ID at-mhs-organization-name}
mHSOrganizationalUnit OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {mHSOrganizationalUnitName}
ID oc-mhs-organizational-unit}
mHSOrganizationalUnitName ATTRIBUTE ::= {
SUBTYPE OF organizationalUnitName 60
WITH SYNTAX DirectoryString {ub-organizational-unit-name-length}
ID at-mhs-organizational-unit-name}
mHSPerson OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {mHSSurname}
MAY CONTAIN {mHSGivenName|
mHSInitials|
mHSGenerationalQualifier}
ID oc-mhs-person} 70
mHSSurname ATTRIBUTE ::= {
SUBTYPE OF surname
WITH SYNTAX DirectoryString {ub-surname-length}
ID at-mhs-surname}
mHSGivenName ATTRIBUTE ::= {
SUBTYPE OF givenName
WITH SYNTAX DirectoryString {ub-given-name-length}
ID at-mhs-given-name} 80
mHSInitials ATTRIBUTE ::= {
SUBTYPE OF initials
WITH SYNTAX DirectoryString {ub-initials-length}
ID at-mhs-initials}
mHSGenerationQualifier ATTRIBUTE ::= {
SUBTYPE OF generationQualifier
WITH SYNTAX DirectoryString {ub-generation-qualifier-length}
ID at-mhs-generation-qualifier} 90
mHSNamedObject OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {mHSCommonName}
ID oc-mhs-named-object}
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mHSCommonName ATTRIBUTE ::= {
SUBTYPE OF commonName
WITH SYNTAX DirectoryString {ub-common-name-length}
ID at-mhs-common-name} 100
mHSX121 OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {mHSX121Address}
ID oc-mhs-x121}
mHSX121Address ATTRIBUTE ::= {
SUBTYPE OF name
WITH SYNTAX DirectoryString {ub-x121-address-length}
ID at-x121-address} 110
mHSDomainDefinedAttribute OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {
mHSDomainDefinedAttributeType|
mHSDomainDefinedAttributeValue}
ID oc-mhs-domain-defined-attribute}
mHSDomainDefinedAttributeType ATTRIBUTE ::= {
SUBTYPE OF name 120
WITH SYNTAX DirectoryString {ub-domain-defined-attribute-type-length}
SINGLE VALUE
ID at-mhs-domain-defined-attribute-type}
mHSDomainDefinedAttributeValue ATTRIBUTE ::= {
SUBTYPE OF name
WITH SYNTAX DirectoryString {ub-domain-defined-attribute-value-length}
SINGLE VALUE
ID at-mhs-domain-defined-attribute-value}
130
mHSTerminalID OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {mHSTerminalIDName}
ID oc-mhs-terminal-id}
mHSTerminalIDName ATTRIBUTE ::= {
SUBTYPE OF name
WITH SYNTAX DirectoryString {ub-terminal-id-length}
ID at-mhs-terminal-id-name} 140
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RFC 2294 Directory Information Tree March 1998
mHSNumericUserIdentifier OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {mHSNumericUserIdentifierName}
ID oc-mhs-numeric-user-id}
mHSNumericeUserIdentifierName ATTRIBUTE ::= {
SUBTYPE OF name
WITH SYNTAX DirectoryString {ub-numeric-user-id-length} 150
ID at-mhs-numeric-user-id-name}
Figure 2: O/R Address Hierarchy
The hierarchy is defined so that:
1. The representation is defined so that it is straightforward to
make a mechanical transformation in either direction. This
requires that each node is named by an attribute whose type can
determine the mapping.
2. Where there are multiple domain defined attributes, the first
in the sequence is the most significant.
3. Physical Delivery (postal) addresses are not represented in
this hierarchy. This is primarily because physical delivery can
be handled by the Access Unit routing mechanisms defined in [4],
and there is no need for this representation.
4. Terminal and network forms of address are not handled, except
for X.121 form, which is useful for addressing faxes.
5. MHSCountry is defined as a subclass of Country, and so the
same entry will be used for MHS Routing as for the rest of the
DIT.
6. The numeric country code will be an alias.
7. ADMD will always be present in the hierarchy. This is true
in the case of " " and of "0". This facilitates an easy
mechanical transformation between the two forms of address.
8. Each node is named by the relevant part of the O/R Address.
9. Aliases may be used in other parts of the tree, in order to
normalize alternate values. Where an alias is used, the value of
the alias should be present as an alternate value in the node
aliased to. Aliases may not be used for domain defined
attributes.
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RFC 2294 Directory Information Tree March 1998
10. Domain Defined Attributes are named by a multi-valued RDN
(Relative Distinguished Name), consisting of the type and value.
This is done so that standard attribute syntaxes can be used.
11. Where an O/R Address has a valid Printable String and T.61 form,
both must be present, with one as an alias for the other. This
is so that direct lookup of the name will work, independent of
the variant used. When both are present in an O/R Address being
looked up, either may be used to construct the distinguished
name.
12. Personal name is handled by use of the mHSPerson object class.
Each of the components of the personal name will be present in
the relative distinguished name, which will usually be multi-
valued.
The relationship between X.400 O/R Addresses and the X.400 Entries
(Attribute Type and Object Class) are given in Table 2. Where there
are multiple Organizational Units or Domain Defined Attributes, each
component is mapped onto a single X.500 entry.
Note: When an X.121 address is used for addressing fax transmission,
this may only be done relative to the PRMD or ADMD. This is in
line with the current X.400 standards position. This means that
it is not possible to use this form of addressing for an
organizational or departmental fax gateway service.
O/R Address Object Class Naming Attribute
----------- ------------ ----------------
C mHSCountry countryName
or
mHSNumericCountryName
A aDMD aDMDName
P pRMD pRMDName
O mHSOrganization mHSOrganizationName
OU/OU1/OU2 mHSOrganizationalUnit mHSOrganizationalUnitName
OU3/OU4
PN mHSPerson personName
CN mHSNamedObject mHSCommonName
X121 mHSX121 mHSX121Address
T-ID mHSTerminalID mHSTerminalIDName
UA-ID mHSNumericUserIdentifier mHSNumericUserIdentifierName
DDA mHSDomainDefinedAttribute mHSDomainDefinedAttributeType
and
mHSDomainDefinedAttributeValue
Table 2: O/R Address relationship to Directory Name
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RFC 2294 Directory Information Tree March 1998
2 Notation
O/R Addresses are written in the standard X.400 Notation.
Distinguished Names use the string representation of distinguished
names defined in [3]. The keywords used for the attributes defined
in this specification are given in Table 3.
3 Example Representation
The O/R Address:
I=S; S=Kille; OU1=CS; O=UCL,
P=UK.AC; A=Gold 400; C=GB;
would be represented in the directory as:
MHS-I=S + MHS-S=Kille, MHS-OU=CS, MHS-O=UCL,
Attribute Keyword
--------- -------
mHSNumericCountryName MHS-Numeric-Country
aDMDName ADMD
pRMDName PRMD
mHSOrganizationName MHS-O
mHSOrganizationalUnitName MHS-OU
mHSSurname MHS-S
mHSGivenName MHS-G
mHSInitials MHS-I
mHSGenerationalQualifier MHS-GQ
mHSCommonName MHS-CN
mHSX121Address MHS-X121
mHSDomainDefinedAttributeType MHS-DDA-Type
mHSDomainDefinedAttributeValue MHS-DDA-Value
mHSTerminalIDName MHS-T-ID
mHSNumericeUserIdentifierName MHS-UA-ID
Table 3: Keywords for String DN Representation
PRMD=UK.AC, ADMD=Gold 400, C=GB
4 Mapping from O/R Address to Directory Name
The primary application of this mapping is to take an X.400 encoded
O/R Address and to generate an equivalent directory name. This
mapping is only used for selected types of O/R Address:
Kille Standards Track [Page 9]
RFC 2294 Directory Information Tree March 1998
o Mnemonic form
o Numeric form
o Terminal form, where country is present and X121 addressing
is used
Other forms of O/R address are handled by Access Unit mechanisms.
The O/R Address is treated as an ordered list, with the order as
defined in Table 1. For each O/R Address attribute, generate the
equivalent directory naming attribute. In most cases, the mapping is
mechanical. Printable String or Teletex encodings are chosen as
appropriate. Where both forms are present in the O/R Address, either
form may be used to generate the distinguished name. Both will be
represented in the DIT. There are two special cases:
1. A DDA generates a multi-valued RDN
2. The Personal Name is mapped to a multi-valued RDN
In many cases, an O/R Address will be provided, and only the higher
components of the address will be represented in the DIT. In this
case, the "longest possible match" should be returned.
5 Mapping from Directory Name to O/R Address
The reverse mapping is also needed in some cases. All of the naming
attributes are unique, so the mapping is mechanically reversible.
6 Acknowledgments
Acknowledgments for work on this document are given in [4].
References
[1] The Directory --- overview of concepts, models and services,
1993. CCITT X.500 Series Recommendations.
[2] Kille, S., "MIXER (Mime Internet X.400 Enhanced Relay): Mapping
between X.400 and RFC 822/MIME", RFC 2156, January 1998.
[3] Kille, S., "A String Representation of Distinguished Names",
RFC 1779, March 1995.
[4] Kille, S., "Use of an X.500/LDAP directory to support MIXER address
mapping", RFC 2164, January 1998.
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RFC 2294 Directory Information Tree March 1998
[5] Kille, S., "X.400-MHS use of the X.500 directory to support
X.400-MHS routing", RFC 1801, June 1995.
[6] CCITT recommendations X.400 / ISO 10021, April 1988. CCITT
SG 5/VII / ISO/IEC JTC1, Message Handling: System and Service
Overview.
7 Security Considerations
This protocol introduces no known security risks.
8 Author's Address
Steve Kille
Isode Ltd.
The Dome
The Square
Richmond
TW9 1DT
England
Phone: +44-181-332-9091
EMail: S.Kille@ISODE.COM
X.400: I=S; S=Kille; P=ISODE; A=Mailnet; C=FI;
Kille Standards Track [Page 11]
RFC 2294 Directory Information Tree March 1998
A Object Identifier Assignment
mhs-ds OBJECT IDENTIFIER ::= {iso(1) org(3) dod(6) internet(1) private(4)
enterprises(1) isode-consortium (453) mhs-ds (7)}
tree OBJECT IDENTIFIER ::= {mhs-ds 2}
oc OBJECT IDENTIFIER ::= {tree 1}
at OBJECT IDENTIFIER ::= {tree 2}
oc-admd OBJECT IDENTIFIER ::= {oc 1} 10
oc-mhs-country OBJECT IDENTIFIER ::= {oc 2}
oc-mhs-domain-defined-attribute OBJECT IDENTIFIER ::= {oc 3}
oc-mhs-named-object OBJECT IDENTIFIER ::= {oc 4}
oc-mhs-organization OBJECT IDENTIFIER ::= {oc 5}
oc-mhs-organizational-unit OBJECT IDENTIFIER ::= {oc 6}
oc-mhs-person OBJECT IDENTIFIER ::= {oc 7}
oc-mhs-x121 OBJECT IDENTIFIER ::= {oc 8}
oc-prmd OBJECT IDENTIFIER ::= {oc 9}
oc-mhs-terminal-id OBJECT IDENTIFIER ::= {oc 10}
oc-mhs-numeric-user-id OBJECT IDENTIFIER ::= {oc 11} 20
at-admd-name OBJECT IDENTIFIER ::= {at 1}
at-mhs-common-name OBJECT IDENTIFIER ::= {at 2}
at-mhs-domain-defined-attribute-type OBJECT IDENTIFIER ::= {at 3}
at-mhs-domain-defined-attribute-value OBJECT IDENTIFIER ::= {at 4}
at-mhs-numeric-country-name OBJECT IDENTIFIER ::= {at 5}
at-mhs-organization-name OBJECT IDENTIFIER ::= {at 6}
at-mhs-organizational-unit-name OBJECT IDENTIFIER ::= {at 7}
at-prmd-name OBJECT IDENTIFIER ::= {at 10}
at-x121-address OBJECT IDENTIFIER ::= {at 12} 30
at-mhs-terminal-id-name OBJECT IDENTIFIER ::= {at 13}
at-mhs-numeric-user-id-name OBJECT IDENTIFIER ::= {at 14}
at-mhs-surname OBJECT IDENTIFIER ::= {at 15}
at-mhs-given-name OBJECT IDENTIFIER ::= {at 16}
at-mhs-initials OBJECT IDENTIFIER ::= {at 17}
at-mhs-generation-qualifier OBJECT IDENTIFIER ::= {at 18}
Figure 3: Object Identifier Assignment
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Kille Standards Track [Page 13]