Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools


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:

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
 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-

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

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
     -----------------          ------------------          -------
       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].


 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:
                TYPE NOTATION  ::= Parameters Data
                Parameters     ::=  "PARAMETERS" type "IDENTIFIED"
                                    "BY" value(OBJECT IDENTIFIER)
                                  | empty;
                Data           ::= "DATA" type
 To meet these requirements, this document uses the OID
 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
  1. - 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
     (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-
 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
     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

 No attempt is made to turn the parameters of Extended Body Parts into
 MIME parameters.  (This task is the responsibility of the recipient's
 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=
 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
     (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

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
 If nothing is specified, the default parameter settings are:
 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

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;
 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
 When mapping from X.400 to MIME, the "repertoire" parameter is
 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

7.2. GeneralText - text/plain (ISO-8859)

 X.400 Body Part: GeneralText; CharacterSets in
 MIME Content-Type: text/plain; charset=ISO-8859-(1-9)
 Conversion Type: Byte copy
 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
 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
 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
 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
 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)
     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
 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
 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
 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
 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
     (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

        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

 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
 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:
 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
 N-7034 Trondheim
 Steven J. Thompson
 Soft*Switch, Inc.
 640 Lee Road
 Wayne, PA 19087
 Phone: (215) 640-7556

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
 [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
 [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]

/data/webs/external/dokuwiki/data/pages/rfc/rfc1494.txt · Last modified: 1993/08/25 18:12 by

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki