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-
- CURRENT_MEETING_REPORT_
-
- Reported by Robert Hagens/Univeristy of Wisconsin
-
- AGENDA
-
- o Announcement of new name
- o Status of the quest for "NREN"
- o Review of Scope
- - 822 <-> X.400 gateway issues (RFC 987 and successors)
- - X.400 operational issues in a dual protocol internet
- o Review of Issues
- - 822 <-> X.400 Gateways
- * RFC 987 gateway background
- * Table Maintenance
- * Locating a Gateway
- * ORAddress Structure
- - X.400 Operation
- * Routing to destination or 822 gateway
- * Use of Internet Technology
- * Mixed Stacks
- * MTA names
- * Use of "NREN"
- Presentation of a new, unified address structure
- ooEnumerating and discussion of major tasks
-
-
- MINUTES
-
- The meeting was convened by chairman Rob Hagens. An attendance list
- will be published with the Proceedings of the IETF. The Domain Name WG
- meet jointly with the OSI-X400 WG during the afternoon.
-
- WORKING GROUP SCOPE
-
- The scope of the WG was presented:
-
-
- o RFC 822 <-> X.400 Gateway Issues
- - maintenance of RFC 987 mapping tables
- - routing toward a gateway
- o X.400 Operational Issues
- - Structure of OR-Addresses in the Internet
- - X.400 Routing
- - Nameservers
-
-
- The group determined that (with the exception of determining the
- structure of OR-Addresses in the Internet), they should not try to solve
- "pure-OSI" problems. These problems fall into the domain of other OSI
- groups. The WG should develop and maintain a close relationship with
- such groups:
-
- o NIST X.400 SIG
- o NIST X.500 SIG
- o GOSIP X.400 committee
-
-
- PRESENTATION OF ISSUES
-
- Rob Hagens presented a list of issues facing the WG. That list is
- included here:
-
-
- Issues, Problems, and Proposed Solutions to
- X.400 and 987 Gatewaying in the Internet
-
-
- 1. X.400-RFC 822 Gateway Issues
- (a) Background
-
- This background information serves as a very brief tutorial on
- RFC 987. The information presented below is far from complete.
- It is strongly recom- mended that anyone interested in the
- issues dis- cussed below should obtain and read RFC 987.
- RFC 987 specifies how messages should be gatewayed between RFC
- 822 based systems and X.400 (1984) based systems. Although the
- RFC describes the translation of various protocol elements from
- one system to the other, the following discussion is limited
- only to the translation of addresses.
- RFC 987 specifies that translation from one address space to
- another may occur in 2 ways. The normal method of translation
- (table lookup) is used when sub-trees of the different name
- spaces are associ- ated via mapping tables. The fall back
- method of translation (encoding in the other address space's
- format) is used when table lookup fails.
- Table lookup is accomplished through the use of 2 separate
- tables: an RFC 822 -> X.400 table, and an X.400 -> RFC 822
- table. Each entry in the tables is indexed by a key. The
- address to be mapped is compared against each key in the table.
- The com- parison that matches the most components is selected
- (i.e., the "longest" match). The value associated with the key
- is a template that is used to construct the translated address.
-
- i. Table Driven Mapping
- For example, the 822 domain "merit.edu" could be associated
- with the OR Address space "C=US, PRMD=NREN, O=MERIT.EDU" in
- a mapping table. Thus, when translating the 822 address
- "hwb@merit.edu", the domain specification "merit.edu" would
- be compared against the various keys in the table. Assuming
- that the table con- tains two keys "edu" and "merit.edu",
- the longest match "merit.edu" would be selected. The
- template associated with the key "C=US, PRMD=NREN,
- O=MERIT.EDU", would be used to produce the address "C=US,
- PRMD=NREN, O=MERIT.EDU, OU=CS, PN=HWB". In this example,
-
- the translation of the last domain component "cs" is
- performed systemat- ically. The translation of the
- right-hand side of the 822 address "hwb" is specified by RFC
- 987.
- This example shows that a single entry can specify the
- translation for all addresses in the "merit.edu" domain.
- This entry associates the 822 domain "merit.edu" with the
- X.400 namespace under "C=US, PRMD=NREN, O=MERIT.EDU".
- An analogous scheme is used for the opposite direction.
- ii. Mapping Without Tables
- If a mapping table entry is not present, transla- tion may
- still occur. However, in this case, the translation is less
- sophisticated. Translation, in this case amounts to
- encoding the address in the other system's format. RFC 987
- specifies default rules that may be used to perform this
- encoding. These rules specify the manner in which an RFC
- 822 address may be encoded in X.400, and vice versa. The
- following examples consider each direction separately:
- iii.RFC 822->X.400
- In this direction, the domain-defined attribute "RFC-822"
- may be used to encode an RFC 822 address. For example, if
- an 822 address "hagens@janeb.cs.wisc.edu" was translated by
- a gateway that had an X.400 address "C=US, PRMD=NREN,
- O=MERIT.EDU", then that gateway (in the absence of a mapping
- table entry) would produce the address 'C=US, PRMD=NREN,
- O=MERIT.EDU, DD.RFC- 822="hagens@janeb.cs.wisc.edu"'.
- iv. X.400->RFC 822
- In this direction, left-hand side encoding may be used to
- encode an X.400 address within 822. For example, the X.400
- address "C=FR, ADMD=FRENCH-PTT, O=INRIA, PN=HUITEMA", when
- considered by a gateway with the 822 address "merit.edu",
- would be translated to '"C=FR, ADMD=FRENCH-PTT, O=INRIA,
- PN=HUITEMA"@merit.edu'.
- (b) Issues
- i. Table Maintenance
- The mapping table entries must be kept consistent among all
- the 987 gateways in the world. This is very difficult to
- accomplish by hand. How can the table maintenance task be
- automated?
- ii. Finding the Gateway
- How does a mail router find a 987 gateway? In the
- X.400->RFC 822 direction, it is the responsi- bility of
- X.400 routing. Note: X.400 routing is not defined by any
- standard. In the RFC 822- >X.400 direction, it is the
- responsibility of 822 routing. Conventional MX records
- could be util- ized to solve the problem.
- iii.Structure of X.400 addresses
- It is desirable to provide a default X.400 address for hosts
- within the Internet. This address will be structured so
- that the X.400 address space corresponds with the domain
- namespace. What is the best structure to use for this
- purpose?
- The choice of format of X.400 addresses, and the
- corresponence of these addresses to 822 domains will
-
- determine the contents of the of 987 mapping table entries.
-
- oProposed Solution
-
- The currently proposed solution is to map the top and
- second level domains to the ORAddress "organization"
- attribute. Subsequent lower level domains will be
- mapped to a sequence of "organization unit" attributes.
- For example, "venera.isi.edu" would map to "O=isi.edu,
- OU=venera".
- oUse of 'NREN' as a PRMD name
-
- The intended use of "NREN" as a PRMD name is to identify
- a management domain within which every registered
- Internet entity has a default X.400 Address. This
- address would be based upon the Internet domain name.
- We expect some or all currently registered entities to
- decide for themselves whether they wish to use the
- default or register another name in another way. This
- default provides a useful and helpful option without
- constraining any individual entity to keep what the
- default provides for them.
- Is it necessary to define a second PRMD name which would
- identify a management domain within the NREN that
- utilizes X.400 addresses that are not based upon
- Internet domain names? If this is true, is the original
- use of "NREN" incorrect?
- We need to show "ownership" of the name "NREN" so that
- other groups do not have the right to register it.
- Trademarking is the first step. Other uses of "NREN"
- should be looked into. Any way that we can show "use"
- of the name will help establish our "ownership".
- 2. X.500 Operation Issues
- (a) Issues
- i. Distinguished Names
-
- Who will determine the structure of X.500 dis- tinguished
- names (and the objects they locate) for use within the
- Internet community?
- ii. DNS coexistence
-
- How should the DNS and X.500 coexist?
- iii.Domain Distinguished Names
-
- Is it acceptable, for transition purposes only, to suggest
- that Domain names be used as Dis- tinguished names?
-
-
- DISCUSSION OF ISSUES
-
- Non-USA Internet Sites
-
-
- The default OR Address may not be acceptable for Internet sites that are
- not within the USA. 1) The WG cannot mandate the format of addresses
- within a foreign country. 2) the NREN is a national object. Are these
- reasons sufficient to prevent the definition of a default name using
- NREN? At least, it should be made clear that the default name is valid
- for USA-Internet sites only. This may not be inappropriate if many
- foreign countries have already defined the X.400 registration policy
- that would affect the foreign Internet sites.
-
- "NREN"
-
-
- The name "NREN" was originally choosen to be a PRMD name. The purpose
- of this PRMD was to contain OR Addresses based upon Domain Names. It
- was suggested that perhaps "NREN" is not appropriate for this use. No
- other name was decided upon. Possible candidates are names that convey
- some concept of Domain Names, such as "DN". This change would allow the
- name "NREN" to be used by a FRICC-run PRMD.
-
- Another option for a PRMD name would be to use the numeric form.
-
- The effort to pre-register "NREN" as an ANSI OSI Organization name
- failed. It is not clear that the OSI X.400 WG should attempt to
- register the name until its exact use has been determined.
-
- It was suggested that the WG should consider producing a specification
- for written OR Addresses.
-
- PRESENTATION OF A NEW, UNIFIED ADDRESS FORMAT
-
- Paul Mockapetris presented his ideas regarding a new style of address.
- He would like to see the world move forward with the development of a
- unified, simple address structure. His proposal is a format that has
- RFC 822 compatible syntax, whose semantic value is that of an X.500
- distinguished name. These new addresses would be very short and
- user-friendly. The new addresses could be used to look up both X.400
- ORAddresses as well as conventional 822 addresses. The look up
- mechanism could utilize the DNS as well as X.500.
-
- GATEWAY SCENERIOS
-
- A discussion of RFC 822 - X.400 gateway (987) scenarios produced the
- following questions:
-
-
- o Will any 987 gateway provide connectivity to every X.400 MTA?
- The answer to this question will determine whether an 822 transfer
- agent must choose a specific 987 gateway based upon the destination
- address, or if the closest, default 987 gateway will always
- suffice.
- o Is there really benefit to table driven mappings or is it
- sufficient to simply use default encodings?
-
-
- A scheme that utilizes the DNS to aid a 987 gateway was discussed. The
- scheme requires the following components:
-
-
- o An ASCII (canonical) representation of ORAddresses.
- o A new tree of the DNS that is based upon canonical ORAddresses
- strings (called ORADDR). This tree is populated with MX records
- (that store the SMTP 822 address of 987 gateways), and TO-SMTP RRs.
- o Two new DNS resource records. TO-SMTP RRs are stored in the ORADDR
- tree. They contain the information necessary to translate an X.400
- address into an 822 address. TO-X400 RRs are stored in the
- existing DN tree. They contain information necessary to translate
- SMTP 822 addresses into X.400 addresses. A distributed collection
- of TO-SMTP and TO-X400 records correspond to the 987 mapping tables
- X.400 to RFC 822 (mapping 1) and RFC 822 to X.400 (mapping 2),
- respectively.
-
-
- A sample scenario would be:
-
-
- 822->X.400
-
-
- Case A The destination address is an SMTP address which has been
- previously associated with an ORAddress. This means that
- there is a TO-X400 RR that describes how to translate the SMTP
- 822 address into an ORAddress. The originating transfer agent
- will look up the destination address and receive an MX record
- and a TO-X400 RR. The MX record identifies a 987 gateway and
- is used to transfer the message to that gateway. The TO-X400
- record is ignored by the originator.
- When the 987 gateway receives the message, it will lookup the
- destination address and receive an MX and TO-X400 RR. The MX
- record is ignored, but the TO-X400 RR is used to translate the
- destination address into an ORAddress.
- Case B The destination address is an ORAddress. The originating
- transfer agent will look up the destination ORAddress in the
- ORADDR tree and receive an MX record. The MX record
- identifies a 987 gateway and is used to transfer the message
- to that gateway. The destination address sent in the SMTP
- envelope will contain "ORAddress"@gateway.
-
-
- X.400->822
-
-
- Routing to the 987 gateway is not within the scope of the WG; it is
- assumed that the message has already reached the 987 gateway.
-
-
- Case A The destination address is an ORAddress which has been
- previously associated with an SMTP 822 address (sub)tree.
- This means that there is a TO-SMTP RR that describes how to
- translate the ORAddress into an SMTP 822 address.
- When the 987 gateway receives the message, it will lookup the
- destination address in the ORADDR tree and receive a TO-SMTP
- RR. The TO-SMTP RR is used to translate the destination
- address into an SMTP 822 address.
- Case B The destination address is an 822 address which has been
- encoded in an ORAddress.
- When the 987 gateway receives the message, it will translate
- the destination address into an 822 address using the default
- encoding rules.
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