and finally becomes
SMTPGW::In%"Jim.Clay@cs.UCL.AC.UK"
where 'SMTPGW' is the DECnet Phase IV node name of the machine
running the RFC822 to Mail-11 gateway. Again, in case the machine
running the RFC822 to Mail-11 gateway is a DECnet/OSI one (like
OMNI:.US.VA.CENTRL) we would get
OMNI:.US.VA.CENTRL::In%"Jim.Clay@cs.UCL.AC.UK"
7.4.2. Mail-11 --> RFC822 --> X.400
Some of the possible mapping described in section 7.3 for Phase IV
apply to the Mail-11 address, hiding completely its origin. The MIXER
apply on the last step.
an example:
RELAY::MYNODE::BETTY
could map into RFC822 as
BETTY%MYNODE@RELAY.dnet.gw1.it
and accordingly to MIXER
C=it; A=garr; P=dom1; O=gw1; OU=RELAY; S=BETTY(p)MYNODE;
where 'dnet.gw1.it' is the domain of the machine running the Mail-11
to RFC822 gateway.
7.4.3. X.400 --> Mail-11 --> RFC822
The X.400 address is stored into Mail-11 'f-address' element as
described in sections 5.3 and 5.4; then if the Mail-11 to RFC822
gateway is able to understand the presence of a 'x400-text-address'
nto the Mail-11 address, then it applies MIXER to it, and encodes
header. Otherwise it applies the rules described in 7.3.
an example:
C=gb; ADMD=Gold 400; PRMD=AC.UK; O=UCL; OU=cs; G=Jim; S=Clay;
will be encoded like
X4TDEC::gw%"/C=gb/A=Gold 400/P=AC.UK/O=UCL/OU=cs/G=Jim/S=Clay"
If the Mail-11 to RFC822 gateway recognise the x400-text-address,
then the address becomes, accordingly to MIXER
Jim.Clay@cs.UCL.AC.UK
and the following RFC822 header line is added
Received: from X4TDEC with DECnet (Mail-11) on xx-xxx-xxxx.
Otherwise one of the dumb rules could produce
gw%"/C=gb/A=Gold 400/P=AC.UK/O=UCL/OU=cs/G=Jim/S=Clay"@X4TDEC.doms
The case with DECnet/OSI Mail-11 is conceptually identical.
7.4.4. RFC822 --> Mail-11 --> X.400
The RFC822 address is encoded in Mail-11 f-address element as
described in sect. 7.2; then if the Mail-11 to X.400 gateway is able
to understand the presence of an 'RFC822-address' into the Mail-11
address, then it applies MIXER to it, and encodes 'route' and applies
the rules described in 5.2 and 5.5.
an example:
Jim.Clay@cs.UCL.AC.UK
will be encoded like
SMTPGW::In%"Jim.Clay@cs.UCL.AC.UK"
If the Mail-11 to X.400 gateway recognise the RFC822-address, then
the address becomes, accordingly to MIXER
C=gb; ADMD=Gold 400; PRMD=AC.UK; O=UCL; OU=cs; G=Jim; S=Clay;
and a 'trace' record is added into the X.400 P1 data, stating that a
node named SMTPGW was crossed.
Otherwise dumb rule produces
C=it; ADMD=garr; DD.Dnet=HEP;
DD.Mail-11=SMTPGW::In(p)(q)Jim.Clay(a)cs.UCL.AC.UK(q)
Again, the case for DECnet/OSI Mail-11 addresses, is conceptually
identical.
7.4.5. RFC822 --> X.400 --> Mail-11
We apply MIXER to the first conversion, obtaining an X.400 address.
Then the rules described in sections 5.3 and 5.4 are used to store
the X.400 address as 'x400-text-address' into the Mail-11.
an example:
Jim.Clay@cs.UCL.AC.UK
maps accordingly to MIXER to
C=gb; ADMD=Gold 400; PRMD=AC.UK; O=UCL; OU=cs; G=Jim; S=Clay;
and finally becomes
SMTPGW::gw%"/C=gb/A=Gold 400/P=AC.UK/O=UCL/OU=cs/G=Jim/S=Clay"
where 'SMTPGW' is the DECnet Phase IV node name of the machine
running the X.400 to Mail-11 gateway. No differences also for
DECnet/OSI Mail-11 addresses.
7.4.6. Mail-11 --> X.400 --> RFC822
The Mail-11 address is encoded as specified in sections 5.2 and 5.5;
then MIXER is used to convert the address in RFC822.
an example:
RELAY::MYNODE::BETTY
maps into X.400 as
C=it; ADMD=garr; DD.Dnet=OMNI; DD.Mail-11=RELAY::MYNODE::BETTY;
and accordingly to MIXER
"/C=it/A=garr/DD.Dnet=OMNI/DD.Mail-11=RELAY::MYNODE::BETTY"@gw2.it
where 'gw2.it' is the domain of the machine running the MIXER
gateway.
7.4. Conclusions
A standard way of mapping Mail-11 addresses into RFC822 and vice
versa is feasible. A suggestion is thus made to unify all existing
and future implementations. It should be noted, however, that it
could be impossible (in case of DECnet Phase IV) to specify in these
mappings the name of the decnet community owning the encoded address,
as it can be always done for X.400; thus the implementation of the
'intelligent' gateway in this case could result impossible.
Chapter 8 - Notifications and Probes
8.1. Overview
Mail-11 is a real time protocol, i.e. connection is established
directly to the destination node. This makes possible some level of
services like verification of an address, and delivery confirmation.
However, Mail-11 User Agents ususally do not support notification or
probe services, whereas it is possible to deliver the result of a
notification or a probe to Mail-11. In this section we will briefly
describe the level of service which can be obtained on these services
when Mail-11 is involved.
8.2. Delivery of Notifications via Mail-11
As described in the previous chapters, it is possible to transport
also in Mail-11 with minimal loss of information complex information.
This also includes Notifications. In fact Notifications in
RFC822/MIME are encoded as MIME multipart messages: there are thus no
problems in transporting these messages in Mail-11 as any other MIME
message. Also X.400 Notifications can be transported and delivered
via Mail-11: MIXER describes in fact how to convert them into MIME
multipart messages, taking the problem back to the previous
situation.
Even when Mail-11 is just an intermediate step for a Notification
message, this consideration just enable support for the service.
8.3. Generation of Notifications and Probes from Mail-11
Although Mail-11 does not support Notification or Probe, the service
could also be supported at gateway level. In fact, due to real time
nature of Mail-11 protocol, the gateway could be reasonably sure that
delivery until the other end of the Mail-11 path was successful or
unsuccessful (and try to verify the feasibility of a delivery in case
a Probe as requested). However, Mail-11 could just be an intermediate
relay service, vanishing the value of the information.
Implementation of this kind of service at gateway level is thus
questionable, and if done, should clearly state the situation where
it was generated, and the "confidence level" it conveys.
Security Considerations
Security issues are not discussed in this memo.
Acknowledgements
I wish to thank all those people who read the first draft and
contributed a lot with their useful suggestions to the revision of
this document, in particular RARE WG1 and IETF X.400 ops group
members and S. E. Kille.
Thanks also to a number of implementors (among which Ned Freed,
Julian Onions, The Hebrew University of Tel Aviv - Pine VMS support
team), to the HEPnet Mail Technical Committee and to all my Mail-11
"end users", in particular Enzo Valente, for their suggestions and
wishes which helped me really a lot to prepare this revision of
former RFC1405.
References
[1] CCITT, "CCITT Recommendations X.400-X.430", Message Handling
Systems: Red Book, October 1984.
[2] CCITT, "CCITT Recommendations X.400-X.420", Message Handling
Systems: Blue Book, November 1988.
[3] CCITT/ISO, "CCITT Recommendations X.400/ ISO IS 10021-1,"
Message Handling: System and Service Overview , December 1992.
[4] Crocker D., "Standard of the Format of ARPA Internet Text
Messages", STD 11, RFC822, UDel, August 1982.
[5] Kille, S., "MIXER (Mime Internet X.400 Enhanced Relay):
Mapping between X.400 and RFC822/MIME", RFC2156, January
1998.
[6] Alvestrand H., Kille S., Miles R., Rose M., and Thompson S.,
(MIME-MHS) "Mapping between X.400 and RFC-822 Message Bodies,"
RFC1495, Aug 1993.
[7] Digital Equipment Corp., "VMS Mail Utility".
[8] Joiner Associates Inc., "Jnet User's Manual".
[9] PMDF User's Guide.
[10] Alvestrand, H. "Writing X.400 O/R Names", UNINETT / RFC1685,
August 1994.
[11] CCITT, "F.401 CCITT Message Handling Services - Operations and
Definitions of Service - Naming and Addressing for Public
Message Handling Services, Annex B (08/92)", August 1992.
Author's Address
Claudio Allocchio
Sincrotrone Trieste
SS 14 Km 163.5 Basovizza
I 34012 Trieste
Italy
Phone: +39 40 3758523
Fax: +39 40 3758565
EMail: Claudio.Allocchio@elettra.Trieste.it
C=it; A=garr; P=Trieste; O=Elettra; S=Allocchio; G=Claudio;
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