rfc2162.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.


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   Again for DECnet/OSI addresses:

        C=xx; ADMD=yyy; PRMD=www; DD.Dnet=net;
        DD.Mail-11=node-clns::localpart;

   maps into

        gwnode::gw%"C=xx;ADMD=yyy;PRMD=www;DD.Dnet=net;
        DD.Mail-11=node-clns::localpart;"


5.3.1. Examples

   Let us suppose that:

     - the DECnet network name (net) is 'OMNI';
     - the DECnet node name of the gateway (gwnode) is '.IT.DM.X4TDEC';
       alias 'X4TDEC' in Phase IV;
     - the Country Code of the gateway is 'IT' and its ADMD is 'garr';

     (and these two fields are enough to identify uniquely the gateway
     within the X.400 MHS).

     C=it; ADMD=garr; DD.Dnet=OMNI;
     DD.Mail-11=X4TDEC::MRGATE::(q)C=ab::A=dsa::P=qwty::OU=mie::S=Cly(q)
       MRGATE::"C=ab::A=dsa::P=qwty::OU=mie::S=Cly"

     C=it; ADMD=garr; DD.Dnet=EASYNET; DD.Mail-11=ROM01::CARLO;
       X4TDEC::gw%"C=it;ADMD=garr;DD.Dnet=EASYNET;
       DD.Mail-11=ROM01::CARLO;"

   (in the above example 'EASYNET' is supposed to be not connected to
   our gateway located on .IT.DM.X4TDEC DECnet node).

5.4. X.400 --> Mail-11

   The mapping of an X.400 O/R address into Mail-11 is done encoding the
   various attributes into the X400-text-address as defined in chapter 4
   of MIXER, and including this as 'f-address'. A 'f-pref' and a the
   DECnet node name of the gateway.











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   Thus

      x400-text-address

   will be encoded like

      gwnode::gw%"x400-text-address"

   having spaces dividing attributes as optional.

5.4.1. Example

   Let us suppose that:

     - the DECnet node name of the gateway (gwnode) is '.IT.DM.X4TDEC'
       alias 'X4TDEC' in Phase IV, and 'net' is 'OMNI'

   Thus

      C=gb; ADMD=G400; PRMD=AC.UK; O=ucl; S=Clay;

   will be encoded like

    X4TDEC::gw%"/C=gb/A=G400/P=AC.UK/O=ucl/S=Clay"

   or its equivalent with the ";" notation and DECnet/OSI 'node'

    OMNI:.IT.DM.X4TDEC::gw%"C=gb;ADMD=G400;PRMD=AC.UK;O=ucl;S=Clay;"

5.5. Mail-11 encoding of X.400 --> X.400

   It can happen that Mail-11 is used to relay messages between X.400
   systems; this will mean multiple X.400/Mail-11 gateway crossing and
   we will encounter Mail-11 addresses containing embedded X.400
   informations. In order to assure path reversibility we must then
   distinguish two cases:















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   - the embedded X.400 address belongs to a domain whose naming and
     routing rules are known to the global X.400 MHS.  In this case the
     mapping is trivial:

       route::gwnode::gw%"x400-text-address"

     or (for DECnet/OSI)

       net:gwnode::gw%"x400-text-address"

   maps into

       x400-text-address

      'route' and 'gwnode' are mapped into X.400 Trace service elements.

   - the encoded X.400 domain does not belong to the global X.400 name
     space. In this case the mapping rule described into section 5.2
     apply:

       route::gwnode::gw%"x400-text-address"

   maps into

       C=xx; ADMD=yyy; DD.Dnet=net;
       DD.Mail-11=route::gwnode::gw(p)(q)x400-text-address(q);

   and (for DECnet/OSI)

       net:gwnode::gw%"x400-text-address"

   maps into

       C=xx; ADMD=yyy; DD.Dnet=net;
       DD.Mail-11=gwnode::gw(p)(q)x400-text-address(q);

   The latter case is deprecated and must be regarded as a possible
   temporary solution only, while waiting to include into the global
   X.400 MHS also this domain.












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5.5.1. Examples

   Let us suppose that:

     - the DECnet network name (net) is 'OMNI';
     - the DECnet node name of the gateway (gwnode) is '.IT.DM.X4TDEC'
       alias 'X4TDEC' in Phase IV;
     - the Country Code of the gateway is 'IT' and its ADMD is 'garr';
       (and these two fields are enough to identify uniquely the
       gateway within the X.400 MHS).

     X4TDEC::gw%"C=fr;ADMD=atlas;PRMD=ifip;O=poly;S=Moreau;"
       C=fr; ADMD=atlas; PRMD=ifip; O=poly; S=Moreau;

     X4TDEC::gw%"C=zz;ADMD= ;PRMD=Botwa;O=Miner;S=Chiuaw;"
       C=it; ADMD=garr; DD.Dnet=OMNI;
       DD.Mail-11=X4TDEC::gw(p)(q)C=zz;ADMD= ;
       PRMD=Botwa;O=Miner;S=Chiuaw;(q)

   (in the above example  C=zz is unknown to the global X.400 MHS)

Chapter 6 - Mapping - Mail-11 / RFC822

6.1 Introduction

   The implementation of a Mail-11 - RFC822 gateway was faced by many
   software developers independently, and was included in many mail
   products which were running on both VMS and UNIX systems. As there
   was not a unique standard mapping way, the implementations resulted
   into a number of possible variant methods to map a Mail-11 address
   into an RFC822 one. Some of these products became then largely
   widespread, starting to create a number of de facto mapping methods.

   In this chapter some sort of standardisation of the mapping problem
   is considered, trying to be compatible with the existing installed
   software. We must also remind that, in some cases, only simple Mail-
   11 addresses could be mapped into RFC822, having complex ones
   producing all sort of quite strange results. In case DECnet/OSI
   Mail-11 addresses are involved we must also notice that only one
   mapping method can be used from/to RFC822 addresses.











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   On the other hand, the mapping of an RFC822 address in Mail-11 was
   quite straightforward, resulting in a common definition which uses
   "Mail-11 foreign mail protocol" to design an RFC822 address:

      [[node::][node::]...]prot%"rfc-822-address"

   or

      [node::][node::]...]prot::"rfc-822-address"

   or again for DECnet/OSI addresses

      [net:][node-clns::]prot%"rfc-822-address"

   or

      [net:][node-clns::]prot::"rfc-822-addres"

6.2 De facto implementations

   A considerable number of de-facto implementations of Mail-11/RFC822
   gateways is existing. As said in the introduction, the mapping of
   RFC822 addresses in Mail-11 is accomplished using the foreign mail
   protocol syntax and is thus unique.

   On the other hand, Mail-11 addresses are encoded in RFC822 syntax in
   various ways. Here are the most common ones:

        a) "node::user"@gateway-address
        b) user%node@gateway-address
        c) [e-mail]
        d) user%node.dnet@gateway-address

Let's have a quick look to these different choices.

   a - This form simply encloses as quoted Left Hand Side string the
       original Mail-11 address into the RFC822 address of the
       Mail-11/RFC822 gateway. This method is fully conformant with
       RFC822 syntax, and the Mail-11 address is left untouched; thus
       no encoding rules need to applied to it. This method applies also
       easily to DECnet/OSI Mail-11 addresses.

   b - As one will immediately notice, this form has nothing in it
       indicating the address is a Mail-11 one; this makes the encoding
       indistinguishable from a similar encoding of RSCS (BITnet)
       addresses used by some IBM VM Mailer systems. It should thus be
       deprecated.




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   c - In this case a sort of 'reserved word' (DECnet)  embedded into
       the address itself identifies the presence of a Mail-11 original
       address preceding it. The decoding is possible, dropping
       'domains' and extracting 'user' and 'node' parts. However complex
       Mail-11 addresses cannot be mapped properly in this syntax, and
       there is no specific rule for adding the 'domains' part of the
       address.

   d - In this case again there is a 'reserved word' (dnet)  which make
       possible the identification of the original Mail-11 address;
       'gateway-address' points to the Mail-11/RFC822 gateway and 'node'
       and 'user' information can be easily drawn from the address.
       However complex Mail-11 addresses cannot be embedded easily into
       this syntax.

   Note the only methods a) can be successfully used for DECnet/OSI
   Mail-11 addresses, while the other cases are already too complex to
   encode in a unique way such addresses in RFC822.

6.3 Recommended mappings

   From the examples seen in the previous paragraphs we can derive a
   canonical form for representing the mapping between Mail-11 and
   RFC822.

6.3.1 RFC822 mapped in Mail-11

   The mapping of an RFC822 address in Mail-11 is straightforward, using
   the "Mail-11 foreign mail protocol" syntax. The two possible variants
   for Phase IV are:

      [[node::][node::]...]prot%"rfc-822-address"

   or

      [node::][node::]...]prot::"rfc-822-address"

   The equivalent two possible variants for DECnet/OSI are:

      [net:][node-clns::]prot%"rfc-822-address"

   or

      [net:][node-clns::]prot::"rfc-822-address"







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6.3.2 Mail-11 mapped in RFC822

   RFC822 foresee a canonical form for representing non-RFC822
   addresses: put the foreign address in local part (Left Hand Side,
   LHS) is a form as similar as possible to its original syntax. Thus
   the suggested mapping both for Phase IV and DECnet/OSI is:

      "Mail-11-address"@gateway-address

   This format assures also the return path via the appropriate gateway.

6.3.3 Mail-11 (foreign mail protocol) mapped in RFC822

   A Mail-11 address containing a foreign mail protocol syntax can also
   contain the percent '%' character as a separator between the foreign
   protocol name and the actual address itself. In some cases the
   address part can also be an unquoted string. Some examples:

      deliver%swan
      myprot%root.owner
      listserv%my-private.list.A1

   If these addresses are encoded into an RFC822 address using the
   "natural" method described in 6.3.2, they will result in something
   which can be easily mismatched with an address using the percent hack
   in LHS for source routing.

      "myprot%root.owner"@lohost.mydom.edu    (Mail-11 address)

      "LISTSERV%IBMB.BITnet"@bitgate.anu.edu  (% routing address)

   The percent hack is strongly deprecated, and thus should be avoided;
   the second address above shoud be expressed as:

      @bitgate.anu.edu:"[e-mail]"

   However, in order to assure maximum functionality and avoid problems,
   it is recommended to encode Mail-11 addresses containing the foreign
   protocol specification in RFC822 syntax using the DD.Mail-11 and
   DD.dnet qualifiers, i.e.

      "/DD.Mail-11=myprot%root.owner/DD.dnet=OMNI"@lohost.mydom.edu

   The DD.dnet defaults as indicated in the similar cases for the Mail-
   11 / X.400 mappings. This encoding method can, of course, also be
   used to map any other Mail-11 address in RFC822, and is the only one
   which enable to specify the network name ('OMNI' in the above
   example) for DECnet Phase IV Mail-11 addresse. The method is fully



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   compatible with the results also produced by gateways following the
   MIXER specification for Mail-11 addresses encoded in X.400 and then
   translated into RFC822.

Chapter 7 - Complex mapping - X.400 / Mail-11 / RFC822

7.1. The protocol triangle

   The bilateral mappings described in chapters 5 and 6 must be extended
   in order to cover also the case in which also RFC822 addressing is
   involved, and the following triangular situation occurs:


                                   X.400
                                   /  \
                                  /    \
                                 /      \
                             Mail-11----RFC822

   The X.400 - RFC822 side is fully covered by MIXER, and the previous
   chapters in this document cover the Mail-11 - X.400 side and the
   Mail-11 - RFC822 one.

7.2. RFC822 mapped in Mail-11

   The 'RFC822-address' is usually included in 'local-part' as

         route::gwnode::gw%"rfc822-address"

   or the equivalent in DECnet/OSI:

         net:gwnode::gw%"rfc822-address"

   An example in Phase IV

         NVXA23::SMTPGW::in%"[e-mail]"

   and another one in DECnet/OSI

         OMNI:.FR.INET.LABOL.SMTPGW::in%"[e-mail]"

7.3. Mail-11 mapped in RFC822

   There are different styles in mapping a Mail-11 address in RFC822;
   let's have a short summary of what was traditionally done in some
   implementations.





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7.3.1 Mail-11 address encoded in "Left Hand Side" (LHS) of RFC822
      address, using "%" syntax or "::" syntax

        route::node::localpart      (Phase IV)

   maps to

        localpart%node%route@gw-domains

   or

         "route::node::localpart"@gw-domains

   Again, let's consider the DECnet/OSI case:

      net:node-clns::localpart      (DECnet/OSI)

   maps to

        "net:node-clns::localpart"@gw-domains

   (note that "%" encoding does not exist for this case)

   where 'gw-domains' identify uniquely the Mail-11 / RFC822 gateway.