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- Network Working Group H. Alvestrand
- Request for Comments: 1494 SINTEF DELAB
- S. Thompson
- Soft*Switch, Inc.
- August 1993
-
- Equivalences between 1988 X.400 and RFC-822 Message Bodies
-
- Status of this Memo
-
- This RFC specifies an IAB standards track protocol for the Internet
- community, and requests discussion and suggestions for improvements.
- Please refer to the current edition of the "IAB Official Protocol
- Standards" for the standardization state and status of this protocol.
- Distribution of this memo is unlimited.
-
- Table of Contents
-
- 1. Introduction ............................................. 2
- 2. Equivalence Table Definition ............................. 2
- 3. Generic conversions ...................................... 3
- 3.1. Byte copy .............................................. 3
- 3.2. Text Conversion ........................................ 3
- 3.3. Image Conversion ....................................... 3
- 3.4. Tunneling .............................................. 3
- 4. Conversion Table for known X.400 and MIME Types ......... 4
- 4.1. MIME to X.400 Table .................................... 4
- 4.2. X.400 to MIME Table .................................... 4
- 5. Newly defined X.400 Body Parts ........................... 5
- 5.1. Use of OBJECT IDENTIFIERs and ASN.1 MACROS ............. 5
- 5.2. The Generic MIME Extended Body Part .................... 6
- 5.3. The PostScript body part ............................... 7
- 5.4. The JPEG body part ..................................... 7
- 5.5. The GIF body part ...................................... 8
- 6. Newly defined MIME content-types ......................... 8
- 6.1. The application/x400-bp content-type ................... 8
- 6.2. The image/g3fax content-type ........................... 9
- 6.2.1. G3Fax Parameters ..................................... 9
- 6.2.2. Content Encoding ..................................... 10
- 6.3. The Application/ODA content-type ....................... 11
- 7. Equivalence Definitions ................................... 11
- 7.1. IA5Text - text/plain .................................... 11
- 7.2. GeneralText - text/plain (ISO-8859) ..................... 12
- 7.3. BilaterallyDefined - application/octet-stream .......... 13
- 7.4. ODA - application/oda ................................... 14
- 7.5. g3-facsimile - image/g3fax .............................. 15
- 7.6. application/postscript - postscript-body-part .......... 16
- 7.7. application/jpeg - jpeg-body-part ....................... 16
-
-
-
- Alvestrand & Thompson [Page 1]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- 7.8. image/gif - gif-body-part ............................... 16
- 8. OID Assignments ........................................... 17
- 9. IANA Registration form for new mappings ................... 17
- 10. Security Considerations .................................. 18
- 11. Authors' Addresses ....................................... 18
- 12. References ............................................... 19
-
- 1. Introduction
-
- This document is a companion to [1], which defines the principles
- behind interworking between MIME-based RFC-822 mail and X.400 mail.
- This document describes the content of the "IANA MHS/MIME Equivalence
- table" referenced in the companion document, and defines the initial
- configuration of this table. Mappings for new MIME content-types
- and/or X.400 body part types should be registered with the IANA to
- minimize redundancy and promote interoperability.
-
- In MIME, the term "content-type" is used to refer to an information
- object contained in the body of a message. In contrast, X.400 uses
- the term "body part type." In this document, the term "body part" is
- used to refer to either.
-
- Please send comments to the MIME-MHS mailing list:
- <mime-mhs@surfnet.nl>.
-
- 2. Equivalence Table Definition
-
- For each MIME content-type/X.400 body part pair, the Equivalence
- Table will contain an entry with the following sections:
-
- X.400 Body Part
- This section identifies the X.400 Body Part governed by this
- Table entry. It includes any OBJECT IDENTIFIERs or other
- parameters necessary to uniquely identify the Body Part.
-
- MIME Content-Type
- This section identifies the MIME content-type governed by this
- Table entry. The MIME content-type named here must be
- registered with the IANA.
-
- Conversion Type
- This section identifies the type of conversion applied. See the
- section on Generic Conversions for an explanation of the
- possible values.
-
-
-
-
-
-
-
- Alvestrand & Thompson [Page 2]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- Comments (optional)
- This section gives any additional commentary that might be
- useful in understanding the mapping between the X.400 and MIME
- representations.
-
- The initial Equivalence Table entries in this document are described
- using this convention. Any future submissions to the IANA should
- follow this format.
-
- 3. Generic conversions
-
- 3.1. Byte copy
-
- This is the trivial case, that is, no conversion at all. The byte
- stream is simply copied between MIME and X.400.
-
- This is the preferred conversion, since it is the simplest.
-
- Implementors and vendors will be registering OBJECT IDENTIFIERs and
- MIME content-types for their various objects. They are STRONGLY
- ENCOURAGED to specify their content formats such that a gateway can
- use Byte Copy to map between them.
-
- Note that in some cases, it is necessary to define exactly which
- ASN.1 construct to replace with the content of the MIME object.
-
- 3.2. Text Conversion
-
- This type of conversion applies to text objects that cannot be mapped
- using a simple Byte Copy. Conversion involves scanning and
- reformatting the object. For example, the MIME and X.400 objects
- might differ in their encoding of nonstandard characters, or line or
- page breaks.
-
- 3.3. Image Conversion
-
- This conversion type applies to raster images, like Group 3 Facsimile
- or JPEG. Again, it differs from Byte Copy in that it involves
- scanning reformatting the byte stream. It differs from Text
- Conversion in that it is pixel- oriented, rather than character-
- oriented.
-
- 3.4. Tunneling
-
- This is not a conversion at all, but an encapsulation of the object.
- This is the fallback conversion, used when no explicit mapping
- applies.
-
-
-
-
- Alvestrand & Thompson [Page 3]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- 4. Conversion Table for known X.400 and MIME Types
-
- This section itemizes the equivalences for all currently known MIME
- content-types and X.400 body parts.
-
- 4.1. MIME to X.400 Table
-
- MIME content-type X.400 Body Part Section
- ----------------- ------------------ -------
- text/plain
- charset=us-ascii ia5-text 7.1
- charset=iso-8859-x EBP - GeneralText 7.2
- text/richtext no mapping defined 5.2
- application/oda EBP - ODA 7.4
- application/octet-stream bilaterally-defined 7.3
- application/postscript EBP - mime-postscript-body 5.4, 7.6
- image/g3fax g3-facsimile 6.2, 7.5
- image/jpeg EBP - mime-jpeg-body 5.5, 7.7
- image/gif EBP - mime-gif-body 5.6, 7.8
- audio/basic no mapping defined 5.2
- video/mpeg no mapping defined 5.2
-
- Abbreviation: EBP - Extended Body Part
-
- 4.2. X.400 to MIME Table
-
- Basic Body Parts
-
- X.400 Basic Body Part MIME content-type Section
- --------------------- -------------------- -------
- ia5-text text/plain;charset=us-ascii 7.1
- voice No Mapping Defined 6.1
- g3-facsimile image/g3fax 6.2, 7.5
- g4-class1 no mapping defined 6.1
- teletex no mapping defined 6.1
- videotex no mapping defined 6.1
- encrypted no mapping defined 6.1
- bilaterally-defined application/octet-stream 7.3
- nationally-defined no mapping defined 6.1
- externally-defined See Extended Body Parts 6.1
-
- X.400 Extended Body Part MIME content-type Section
- ------------------------- -------------------- -------
- GeneralText text/plain;charset=iso-8859-x 7.2
- ODA application/oda 7.4
- mime-postscript-body application/postscript 5.3, 7.6
- mime-jpeg-body image/jpeg 5.4, 7.7
- mime-gif-body image/gif 5.5, 7.8
-
-
-
- Alvestrand & Thompson [Page 4]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- 5. Newly defined X.400 Body Parts
-
- This section defines new X.400 Body Parts for the purposes of
- interworking with MIME.
-
- All new X.400 Body Parts defined here will be Extended Body Parts, as
- defined in CCITT Recommendation X.420 [2].
-
- 5.1. Use of OBJECT IDENTIFIERs and ASN.1 MACROS
-
- X.420 dictates that Extended Body Parts shall:
-
- (1) use OBJECT IDENTIFIERs (OIDs) to uniquely identify
- the contents, and
-
- (2) be defined by using the ASN.1 Macro:
-
- EXTENDED-BODY-PART-TYPE MACRO::=
- BEGIN
- TYPE NOTATION ::= Parameters Data
- VALUE NOTATION ::= value (VALUE OBJECT IDENTIFIER)
-
- Parameters ::= "PARAMETERS" type "IDENTIFIED"
- "BY" value(OBJECT IDENTIFIER)
- | empty;
- Data ::= "DATA" type
- END
-
- To meet these requirements, this document uses the OID
-
- mime-mhs-bodies
-
- defined in [1], as the root OID for X.400 Extended Body Parts defined
- for MIME interworking.
-
- Each Extended Body Part contains Data and optional Parameters, each
- being named by an OID. To this end, two OID subtrees are defined
- under mime-mhs-bodies, one for Data, and the other for Parameters:
-
- mime-mhs-bp-data OBJECT IDENTIFIER ::=
- { mime-mhs-bodies 1 }
- mime-mhs-bp-parameter OBJECT IDENTIFIER ::=
- { mime-mhs-bodies 2 }
-
- All definitions of X.400 body parts submitted to the IANA for
- registration must use the Extended Body Part Type macro for the
- definition. See the next section for an example.
-
-
-
-
- Alvestrand & Thompson [Page 5]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- Lastly, the IANA will use the mime-mhs-bp-data and mime-mhs-bp-
- parameter OIDs as root OIDs for any new MIME content-type/subtypes
- that aren't otherwise registered in the Equivalence Table.
-
- 5.2. The Generic MIME Extended Body Part
-
- The following X.400 Body Part is defined to carry any MIME content-
- type for which there is no explicit IANA registered mapping.
-
- mime-body-part EXTENDED-BODY-PART-TYPE
- PARAMETERS MimeParameters
- IDENTIFIED BY mime-generic-parameters
- DATA OCTET STRING
- ::= mime-generic-data
-
- MimeParameters ::=
- SEQUENCE {
- content-type IA5String,
- content-parameters SEQUENCE OF
- SEQUENCE {
- parameter IA5String,
- parameter-value IA5String
- }
-
- -- from RFC-1327, sec. 5.1.12
- other-header-fields RFC822FieldList
- }
-
- mime-generic-parameters OBJECT IDENTIFIER ::=
- { mime-mhs-bp-parameter 1 }
- mime-generic-data OBJECT IDENTIFIER ::=
- { mime-mhs-bp-data 1 }
-
- To convert the MIME content-type into the X.400 mime- body-part:
-
- (1) Copy the "type/subtype" string from the MIME
- Content-Type: header field into
- MimeParameters.content-type
-
- (2) For each "parameter=value" string in the MIME
- Content-Type header field, create a
- MimeParameters.content-parameters structure, and copy
- the "parameter" string into MimeParameters.content-
- parameters.parameter field and the "value" string
- into the paired MimeParameters.content-
- parameters.parameter-value field.
-
- (3) Convert the MIME body part into its canonical form.
-
-
-
- Alvestrand & Thompson [Page 6]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- (See appendix H of RFC 1341 [3] for a discussion
- of canonical in this context.) Said another way,
- reverse the transfer encoding to recover the original
- byte stream.
-
- (4) Copy the canonical byte stream into the mime-body-
- part.data octet string.
-
- (5) Remove the Content-type and the Content-transfer-
- encoding header fields from the MIME body part's
- RFC822 header.
-
- (6) Any header fields starting with "Content-" in the
- MIME body part is placed in the optional other-
- header-fields structure. Note that this can only
- occur when the MIME content-type occurs as part of a
- "multipart" content-type.
-
- The mapping from the X.400 mime-body-part to a MIME content-type is
- the inverse of the above steps.
-
- 5.3. The PostScript body part
-
- The following Extended Body Part is defined for PostScript data
- streams. It has no parameters.
-
- postscript-body-part EXTENDED-BODY-PART-TYPE
-
- DATA OCTET STRING
- ::= mime-postscript-body
-
- mime-postscript-body OBJECT IDENTIFIER ::=
- { mime-mhs-bp-data 2 }
-
- 5.4. The JPEG body part
-
- The following Extended Body Part is defined for JPEG data streams.
- It has no parameters.
-
- jpeg-body-part EXTENDED-BODY-PART-TYPE
- DATA OCTET STRING
- ::= mime-jpeg-body
-
- mime-jpeg-body OBJECT IDENTIFIER ::=
- { mime-mhs-bp-data 3 }
-
-
-
-
-
-
- Alvestrand & Thompson [Page 7]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- 5.5. The GIF body part
-
- The following Extended Body Part is defined for GIF data streams. It
- has no parameters.
-
- gif-body-part EXTENDED-BODY-PART-TYPE
- DATA OCTET STRING
- ::= mime-gif-body
-
- mime-gif-body OBJECT IDENTIFIER ::=
- { mime-mhs-bp-data 4 }
-
- 6. Newly defined MIME content-types
-
- This section defines new MIME content-types for the purposes of
- interworking with X.400.
-
- 6.1. The application/x400-bp content-type
-
- This content-type is defined to carry any X.400(88) body part for
- which there is no registered IANA mapping.
-
- The content-type field is
-
- application/x400-bp
-
- The parameters are:
-
- bp-type=<INTEGER or OBJECT IDENTIFIER>
-
- The body contains the raw ASN.1 IPM.body octet stream, including the
- initial tag octet.
-
- If the body is a basic body part, the bp-type parameter is set to the
- number of the body part's context-specific tag, that is, the tag of
- the IPMS.Body.BodyPart component.
-
- If the body is an Extended Body Part, the bp-type parameter is set to
- the OBJECT IDENTIFIER from
-
- IPMS.body.externally-defined.data.direct-reference
-
- No attempt is made to turn the parameters of Extended Body Parts into
- MIME parameters. (This task is the responsibility of the recipient's
- UA).
-
- For example, a basic VideotexBodyPart will have
-
-
-
-
- Alvestrand & Thompson [Page 8]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- Content-type=application/x400-bp; bp-type=6
-
- whilst a Extended Videotex body part will have
-
- Content-type=application/x400-bp; bp-type=2.6.1.4.5
-
- application/x400-bp will need a content-transfer-encoding of base64
- or quoted-printable when carried in 7-bit MIME. Since there is no
- way to know beforehand the content, it is recommended to just inspect
- the first 1 KByte or so of data and choose the one that seems to
- produce the more compact encoding.
-
- If this is not feasible, Base64 is recommended.
-
- 6.2. The image/g3fax content-type
-
- This content-type is defined to carry G3 Facsimile byte streams.
-
- In general, a G3Fax image contains 3 pieces of information:
-
- (1) A set of flags indicating the particular coding
- scheme. CCITT Recommendation T.30 defines how the
- flags are transmitted over telephones. In this
- medium, the flags are carried as parameters in the
- MIME content-type header field.
-
- (2) A structure that divides the bits into pages. CCITT
- recommendation T.30 describes how to define page
- boundaries. A page break algorithm is defined here
- that is independent of how the image data is
- conveyed.
-
- (3) For each page, a sequence of bits that form the
- encoding of the image. CCITT recommendation T.4
- defines the bit image format. This is used without
- change.
-
- 6.2.1. G3Fax Parameters
-
- The following parameters are defined:
-
- (1) page-length - possible values: A4, B4 and Unlimited
-
- (2) page-width - possible values: A3, A4, B4
-
- (3) encoding - possible values: 1-dimensional, 2-
- dimensional, Uncompressed
-
-
-
-
- Alvestrand & Thompson [Page 9]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- (4) resolution - possible values: Fine, Coarse
-
- (5) DCS - a bit string, represented in Base64.
-
- (6) pages - an integer, giving the number of pages in the
- document
-
- If nothing is specified, the default parameter settings are:
-
- page-length=A4
- page-width=A4
- encoding=1-dimensional
- resolution=Coarse
-
- It is possible (but misleading) to view the representation of these
- values as single-bit flags. They correspond to the following bits of
- the T.30 control string and X.400 G3FacsimileParameters:
-
- Parameter T.30 bit X.400 bit
-
- page-length=A4 no bit set
- page-length=B4 19 21
- page-length=Unlimited 20 20
-
- page-width=A4 no bit set
- page-width=A3 18 22
- page-width=B4 17 23
-
- encoding=1-dimensional no bit set
- encoding=2-dimensional 16 8
- encoding=Uncompressed 26 30
-
- resolution=Coarse no bit set
- resolution=Fine 15 9
-
- The reason for the different bit numbers is that X.400 counts bits in
- an octet from the MSB down to the LSB, while T.30 uses the opposite
- numbering scheme.
-
- If any bit but these are set in the Device Control String, the DCS
- parameter should be supplied.
-
- 6.2.2. Content Encoding
-
- X.400 defines the g3-facsimile data stream as a SEQUENCE of BIT
- STRINGs. Each BIT STRING is a page of facsimile image data, encoded
- as defined by Recommendation T.4. The following content encoding is
- reversible between MIME and X.400 and ensures that page breaks are
-
-
-
- Alvestrand & Thompson [Page 10]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- honored in the MIME representation.
-
- An EOL is defined as a bit sequence of
-
- 000000000001 (eleven zeroes and a one).
-
- Each page of the message is delimited by a sequence of six (6) EOLs
- that MUST start on a byte boundary. The image bit stream is padded
- as needed to achieve this alignment.
-
- Searching for the boundary is a matter of searching for the byte
- sequence (HEX) 00 10 01 00 10 01 00 10 01, which cannot occur inside
- the image.
-
- See Section 7.5 for the algorithm on conversion between this encoding
- and the X.400 encoding.
-
- The Base64 content-transfer-encoding is appropriate for carrying this
- content-type.
-
- 6.3. The Application/ODA content-type
-
- The "ODA" subtype of application is used to indicate that a body
- contains information encoded according to the Office Document
- Architecture [4] standards, using the ODIF representation format.
- For application/oda, the Content- Type line should also specify an
- attribute/value pair that indicates the document application profile
- (DAP), using the key word "profile", and the document class, using
- the keyword "class".
-
- For the keyword "class", the values "formatted", "processable" and
- "formatted-processable" are legal values.
-
- Thus an appropriate header field might look like this:
-
- Content-Type: application/oda; profile=Q112;
- class=formatted
-
- Consult the ODA standard [4] for further information.
-
- The Base64 content-transfer-encoding is appropriate for carrying ODA.
-
- 7. Equivalence Definitions
-
- 7.1. IA5Text - text/plain
-
- X.400 Body Part: IA5Text
- MIME Content-type: text/plain; charset=US-ASCII
-
-
-
- Alvestrand & Thompson [Page 11]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- Conversion Type: Byte copy
- Comments:
-
- When mapping from X.400 to MIME, the "repertoire" parameter is
- ignored.
-
- When mapping from MIME to X.400, the "repertoire" parameter is set to
- IA5 (5).
-
- NOTE: The MIME Content-type headers are omitted, when mapping from
- X.400 to MIME, if and only if the IA5Text body part is the only body
- part in the IPMS.Body sequence.
-
- NOTE: IA5Text specifies the "currency" symbol in position 2/4. This
- is converted without comment to the "dollar" symbol, since the author
- of this document has seen many documents in which the position was
- intended to indicate "dollar" while he has not yet seen one in which
- the "currency" symbol is intended.
-
- (For reference: The T.50 (1988) recommendation, which defines IA5,
- talks about ISO registered set number 2, while ASCII, using the
- "dollar" symbol, is ISO registered set number 6. There are no other
- differences.)
-
- 7.2. GeneralText - text/plain (ISO-8859)
-
- X.400 Body Part: GeneralText; CharacterSets in
- 6,100,101,109,110,126,127,138,144,148
- MIME Content-Type: text/plain; charset=ISO-8859-(1-9)
- Conversion Type: Byte copy
- Comments:
-
- When mapping from X.400 to MIME, the character-set chosen from table
- below according to the value of Parameters.CharacterSets.
-
- When mapping from MIME to X.400, GeneralText is an Extended Body
- Part, hence it requires an OID. The OID for the GeneralText body is
- defined in [5], part 8, annex D, as {2 6 1 4 11}. The OID for the
- parameters is {2 6 1 11 11}.
-
- The Parameters.CharacterSets is set from table below according to the
- value of "charset"
-
- NOTE: The GeneralText body part is defined in ISO 10021-8 [5], and
- NOT in the corresponding CCITT recommendation. Its parameters were
- heavily modified in a defect report, and will be a SET OF INTEGER
- (indicating the ISO registry numbers of all the used sets) in the
- next version of the standard.
-
-
-
- Alvestrand & Thompson [Page 12]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- The following table lists the MIME character sets and the
- corresponding ISO registry numbers. If no correspondence is found,
- this conversion fails, and the generic body part approach is used.
-
- MIME charset ISO IR numbers Comment
- -----------------------------------------------
- ISO-8859-1 6, 100 West European "8-bit ASCII"
- ISO-8859-2 6, 101 East European
- ISO-8859-3 6, 109 <regarded as obsolete>
- ISO-8859-4 6, 110 <regarded as obsolete>
- ISO-8859-5 6, 144 Cyrillic
- ISO-8859-6 6, 127 Arabic
- ISO-8859-7 6, 126 Greek
- ISO-8859-8 6, 138 Hebrew
- ISO-8859-8 6, 148 Other Latin-using languages
-
- When converting from MIME to X.400, generate the correct OIDs for use
- in the message envelope's Encoded Information Types by looking up the
- ISO IR number in the above table, and then appending it to the id-
- cs-eit-authority {1 0 10021 7 1 0} OID.
-
- The escape sequences to designate and invoke the relevant character
- sets in their proper positions must be added to the front of the
- GeneralText character string.
-
- 7.3. BilaterallyDefined - application/octet-stream
-
- X.400 Body Part: BilaterallyDefined
- MIME Content-Type: Application/Octet-Stream (no parameters)
- Conversion Type: Byte copy
- Comments:
-
- When mapping from MIME to X.400, if there are parameters present in
- the Content-Type: header field, the conversion fails since the
- BilaterallyDefined Body Part does not have any corresponding ASN.1
- parameters.
-
- DISCUSSION: The parameters "name" "type" and "conversions" are
- advisory, but may in some cases give vital hints on the expected
- handling of the file. The parameter "conversions" is not fully
- defined, but it is expected that it will be useful, so we cannot drop
- it and expect people to be satisfied.
-
- The parameter "padding" changes the interpretation of the last byte
- of the data, and so cannot be deleted.
-
- An option is to prepend an IA5 body part that contains the parameter
- text; this will aid unmodified readers, and can probably be made
-
-
-
- Alvestrand & Thompson [Page 13]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- reversible with suitable chicanery, but is it worth it????
-
- Also, use of BilaterallyDefined Body Parts is specifically deprecated
- in both 1988 and 1992 X.400. It is retained solely for backward
- compatibility with 1984 systems. 1992 X.400 defines a File Transfer
- Body Part to solve this problem (i.e. binary file transfer through
- email). The standard and its regional profiles are not solid enough
- yet to exploit as a solution for this problem.
-
- 7.4. ODA - application/oda
-
- X.400 Body Part: ODA
- MIME Content-Type: application/oda
- Conversion Type: Byte copy
- Comments:
-
- The ODA body part is defined in the CCITT document T.411 [6],
- appendix E, section E.2, "ODA identification in the P2 protocol of
- MHS"
-
- An abbreviated version of its ASN.1 definition is:
-
- oda-body-part EXTENDED-BODY-PART-TYPE
- PARAMETERS OdaBodyPartParameters
- DATA OdaData
- ::= id-et-oda
-
- OdaBodyPartParameters ::= SET {
- document-application-profile [0] OBJECT IDENTIFIER
- document-architecture-class [1] INTEGER {
- formatted (0)
- processable (1)
- formatted-processable(2)}}
-
- id-et-oda OBJECT IDENTIFIER ::= { 2 8 1 0 1 }
-
- Mapping from X.400 to MIME, the following is done:
-
- The Parameters.document-application-profile is mapped onto the MIME
- parameter "profile" according to the table below.
-
- Profile OBJECT IDENTIFIER
-
- Q112 { iso (1) identified-organization (3) ewos (16)
- eg (2) oda (6) profile (0) q112 (1) }
-
- The Parameters.document-architecture-class is mapped onto the MIME
- parameter "class" according to the table below
-
-
-
- Alvestrand & Thompson [Page 14]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- String Integer
-
- formatted formatted(0)
- processable processable(1)
- formatted-processable formatted-processable(2)
-
- NOTE: This parameter is not defined in RFC 1341.
-
- The body of the MIME content-type is the Data part of the ODA body
- part.
-
- When mapping from MIME to X.400, the following steps are done:
-
- The Parameters.document-application-profile and Parameters.document-
- architecture-class are set from the tables above. If any of the
- parameters are missing, the values for Q112 and formatted-processable
- are used.
-
- It is an option for the gateway implementor to try to access them
- from inside the document, where they are defined as
-
- document-profile.document-characteristics.document-architecture-class
-
- document-profile.document-characteristics.document-application-profile
-
- Gateways are NOT required to do this, since the document-
- characteristics are optional parameters. If a gateway does not, it
- simply uses the defaulting rules defined above.
-
- The OBJECT IDENTIFIERs for the document application profile and for
- ODA {2 8 0 0} must be added to the Encoded Information Types
- parameter of the message envelope.
-
- 7.5. g3-facsimile - image/g3fax
-
- X.400 Body part: g3-facsimile
- MIME Content-Type: image/g3fax
- Conversion Type: nearly Byte copy
- Comments:
-
- The Parameters of the X.400 G3Fax body part are mapped to the
- corresponding Parameters on the MIME Image/G3Fax body part and vice
- versa. Note that:
-
- (1) If fineResolution is not specified, pixels will be
- twice as tall as they are wide
-
- (2) If any bit not corresponding to a specially named
-
-
-
- Alvestrand & Thompson [Page 15]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- option is set in the G3Fax NonBasicParameters, the
- "DCS" parameter must be used.
-
- (3) Interworking is not guaranteed if any bit apart from
- those specially named are used in the
- NonBasicParameters
-
- From X.400 to G3Fax, the body is created in the following way:
-
- (1) Any trailing EOL markers on each bitstring is
- removed. The bistring is padded to a byte boundary.
-
- (2) 6 consecutive EOL markers are appended to each
- bitstring.
-
- (3) The padded bitstrings are concatenated together
-
- An EOL marker is the bit sequence 000000000001 (11 zeroes and a one).
-
- From G3Fax to X.400, the body is created in the following way:
-
- (1) The body is split into bitstrings at each occurrence
- of 6 consecutive EOL markers, and trailing EOLs and
- padding are removed
-
- (2) Each bitstring is made into an ASN.1 BITSTRING
-
- (3) The bitstrings are made into an ASN.1 SEQUENCE, which
- forms the body of the G3Fax body part.
-
- 7.6. application/postscript - postscript-body-part
-
- X.400 Body Part: Extended Body Part, OID postscript-body-part
- MIME Content-Type: application/postscript
- Conversion Type: Byte Copy
-
- 7.7. application/jpeg - jpeg-body-part
-
- X.400 Body Part: Extended Body Part, OID jpeg-body-part
- MIME Content-Type: application/jpeg
- Conversion Type: Byte Copy
-
- 7.8. image/gif - gif-body-part
-
- X.400 Body Part: Extended Body Part, OID gif-body-part
- MIME Content-Type: application/gif
- Conversion Type: Byte Copy
-
-
-
-
- Alvestrand & Thompson [Page 16]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- 8. OID Assignments
-
- MIME-MHS-MAPPINGS DEFINITIONS ::= BEGIN
-
-
- IMPORTS
- mail, mime-mhs, mime-mhs-bodies
- FROM MIME-MHS;
-
- mime-mhs-bp-data OBJECT IDENTIFIER ::=
- { mime-mhs-bodies 1}
-
- mime-mhs-bp-parameter OBJECT IDENTIFIER ::=
- { mime-mhs-bodies 2}
-
- mime-generic-data OBJECT IDENTIFIER ::=
- { mime-mhs-bp-data 1}
-
- mime-generic-parameters OBJECT IDENTIFIER ::=
- { mime-mhs-bp-parameter 1}
-
- mime-postscript-body OBJECT IDENTIFIER ::=
- { mime-mhs-bp-data 2}
-
- mime-jpeg-body OBJECT IDENTIFIER ::=
- { mime-mhs-bp-data 3}
-
- mime-gif-body OBJECT IDENTIFIER ::=
- { mime-mhs-bp-data 4};
-
- 9. IANA Registration form for new mappings
-
- To: IANA@isi.edu
- Subject: Registration of new X.400/MIME content type mapping
-
- MIME type name:
-
- (this must have been registered previously with IANA)
-
- X.400 body part:
-
- X.400 Object Identifier for Data:
-
- (If left empty, an OID will be assigned by IANA under
- mime-mhs-bp-data)
-
- X.400 Object Identifier for Parameters:
-
-
-
-
- Alvestrand & Thompson [Page 17]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- (If left empty, an OID will be assigned by IANA under
- mime-mhs-bp-parameter. If it is not used, fill in the
- words NOT USED.)
-
- X.400 ASN.1 Syntax:
-
- (must be an EXTENDED-BODY-PART-TYPE macro, or reference to
- a Basic body part type)
-
- Conversion algorithm:
-
- (must be defined completely enough for independent
- implementation. It may be defined by reference to RFCs).
-
- Person & email address to contact for further information:
-
- INFORMATION TO THE SUBMITTER:
-
- The accepted registrations will be listed in the "Assigned
- Numbers" series of RFCs. The information in the
- registration form is freely distributable.
-
- 10. Security Considerations
-
- Security issues are not discussed in this memo.
-
- 11. Authors' Addresses
-
- Harald Tveit Alvestrand
- SINTEF DELAB
- N-7034 Trondheim
- NORWAY
-
- EMail: Harald.Alvestrand@delab.sintef.no
-
-
- Steven J. Thompson
- Soft*Switch, Inc.
- 640 Lee Road
- Wayne, PA 19087
-
- Phone: (215) 640-7556
- EMail: sjt@gateway.ssw.com
-
-
-
-
-
-
-
-
- Alvestrand & Thompson [Page 18]
-
- RFC 1494 X.400/MIME Body Equivalences August 1993
-
-
- 12. References
-
- [1] Alvestrand, H., Kille, S., Miles, R., Rose, M., and S. Thompson,
- "Mapping between X.400 and RFC-822 Message Bodies", RFC 1495,
- SINTEF DELAB, ISODE Consortium, Soft*Switch, Inc, Dover Beach
- Consulting, Inc., Soft*Switch, Inc., August 1993.
-
- [2] CCITT Recommendation X.420 (1988), Interpersonal Messaging
- System.
-
- [3] Borenstein, N, and N. Freed, "MIME: Mechanisms for Specifying
- and Describing the Format of Internet Message Bodies", RFC 1341,
- Bellcore, Innosoft, June 1992.
-
- [4] ISO 8613; Information Processing: Text and Office System; Office
- Document Architecture (ODA) and Interchange Format (ODIF), Part
- 1-8, 1989.
-
- [5] ISO/IEC International Standard 10021, Information technology -
- Text Communication - Message-Oriented Text Interchange Systems
- (MOTIS) (Parts 1 to 8).
-
- [6] CCITT Recommendation T.411 (1988), Open Document Architecture
- (ODA) and Interchange Format, Introduction and General
- Principles.
-
- [7] Crocker, D., "Standard for the Format of ARPA Internet Text
- Messages", STD 11, RFC 822, UDEL, August 1982.
-
- [8] Hardcastle-Kille, S., "Mapping between X.400(1988) / ISO 10021
- and RFC-822", RFC 1327, University College London, May 1992.
-
- [9] CCITT Recommendation T.4, Standardization of Group 3 Facsimile
- Apparatus for Document Transmission (1988).
-
- [10] CCITT Recommendation T.30, Procedures For Document Facsimile
- Transmission in the General Switched Telephone Network (1988).
-
- [11] CCITT, Data Communication Networks - Message Handling Systems -
- Recommendations X.400 - X.420 (1988 version).
-
- [12] Alvestrand, H., "X.400 Use of Extended Character Sets", RFC
- 1502, SINTEF DELAB, August 1993.
-
-
-
-
-
-
-
-
- Alvestrand & Thompson [Page 19]
-
-