Network Working Group S. Kille
Request for Comments: 1836 ISODE Consortium
Category: Experimental August 1995
Representing the O/R Address hierarchy in the
X.500 Directory Information Tree
Status of this Memo
This memo defines an Experimental Protocol for the Internet
community. This memo does not specify an Internet standard of any
kind. Discussion and suggestions for improvement are requested.
Distribution of this memo is unlimited.
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].
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
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RFC 1836 O/R Addresses in the X.500 DIT August 1995
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.
/\
/ \
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
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RFC 1836 O/R Addresses in the X.500 DIT August 1995
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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RFC 1836 O/R Addresses in the X.500 DIT August 1995
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-lenght}
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
mHSNumericUserIdentifier OBJECT-CLASS ::= {
SUBCLASS OF {top}
MUST CONTAIN {mHSNumericUserIdentifierName}
ID oc-mhs-numeric-user-id}
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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
normalise 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.
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.
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RFC 1836 O/R Addresses in the X.500 DIT August 1995
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
organisational 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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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
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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:
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. Acknowledgements
Acknowledgements for work on this document are given in [4].
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References
[1] The Directory --- overview of concepts, models and services,
1993. CCITT X.500 Series Recommendations.
[2] Kille, S., "Mapping between X.400(1988)/ISO 10021 and RFC 822",
RFC 1327, Department of Computer Science, University College
London, May 1992.
[3] Kille, S., "A String Representation of Distinguished Names",
RFC 1779, Department of Computer Science, University College
London, March 1995.
[4] Kille, S., "MHS Use of the X.500 Directory to Support MHS
Routing, RFC 1801, ISODE Consortium, June 1995.
[5] Kille, S., "Use of the X.500 Directory to Support Mapping between
X.400 and RFC 822 Addresses, RFC 1838, ISODE Consortium,
August 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
Security issues are not discussed in this memo.
8. Author's Address
Steve Kille
ISODE Consortium
The Dome
The Square
Richmond
TW9 1DT
England
Phone: +44-81-332-9091
Internet EMail: S.Kille@ISODE.COM
X.400: I=S; S=Kille; O=ISODE Consortium; P=ISODE;
A=Mailnet; C=FI;
DN: CN=Steve Kille,
O=ISODE Consortium, C=GB
UFN: S. Kille, ISODE Consortium, GB
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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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