Using the Internet DNS to Distribute RFC1327 Mail Address Mapping Tables
RFC 1664
Document | Type |
RFC - Experimental
(August 1994; No errata)
Obsoleted by RFC 2163
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Authors | Claudio Allocchio , Antonio Bonito , Bruce Cole , Silvia Giordano , Robert Hagens | ||
Last updated | 2013-03-02 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 1664 (Experimental) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group C. Allocchio Request for Comments: 1664 A. Bonito Category: Experimental GARR-Italy B. Cole Cisco Systems Inc. S. Giordano Centro Svizzero Calcolo Scientifico R. Hagens Advanced Network & Services August 1994 Using the Internet DNS to Distribute RFC1327 Mail Address Mapping Tables Status of this Memo This memo defines an Experimental Protocol for the Internet community. This memo does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Abstract This memo defines how to store in the Internet Domain Name System the mapping information needed by e-mail gateways and other tools to map RFC822 domain names into X.400 O/R names and vice versa. Mapping information can be managed in a distributed rather than a centralised way. Gateways located on Internet hosts can retrieve the mapping information querying the DNS instead of having fixed tables which need to be centrally updated and distributed. This memo is a joint effort of X400 operation working group (x400ops) and RARE Mail and Messaging working group (WG-MSG). 1. Introduction The connectivity between the Internet SMTP mail and other mail services, including the Internet X.400 mail and the commercial X.400 service providers, is assured by the Mail eXchanger (MX) record information distributed via the Internet Domain Name System (DNS). A number of documents then specify in details how to convert or encode addresses from/to RFC822 style to the other mail system syntax. However, only conversion methods provide, via some algorithm or a set of mapping rules, a smooth translation, resulting in addresses indistinguishable from the native ones in both RFC822 and foreign world. RFC1327 describes a set of mappings which will enable interworking between systems operating the CCITT X.400 (1984/88) Recommendations Allocchio, Bonito, Cole, Giordano & Hagens [Page 1] RFC 1664 Internet DNS for Mail Mapping Tables August 1994 and systems using the RFC822 mail protocol, or protocols derived from RFC822. That document addresses conversion of services, addresses, message envelopes, and message bodies between the two mail systems. This document is concerned with one aspect of RFC1327: the mechanism for mapping between X.400 O/R addresses and RFC822 domain names. As described in Appendix F of RFC1327, implementation of the mappings requires a database which maps between X.400 O/R addresses and domain names, and this database is statically defined. This approach requires many efforts to maintain the correct mapping: all the gateways need to get coherent tables to apply the same mappings, the conversion tables must be distributed among all the operational gateways, and also every update needs to be distributed. This static mechanism requires quite a long time to be spent modifying and distributing the information, putting heavy constraints on the time schedule of every update. In fact it does not appear efficient compared to the Internet Domain Name Service (DNS). More over it does not look feasible to distribute the database to a large number of other useful applications, like local address converters, e-mail User Agents or any other tool requiring the mapping rules to produce correct results. A first proposal to use the Internet DNS to store, retrieve and maintain those mappings was introduced by two of the authors (B. Cole and R. Hagens) adopting two new DNS resource record (RR) types: TO- X400 and TO-822. This new proposal adopts a more complete strategy, and requires one new RR only. The distribution of the RFC1327 mapping rules via DNS is in fact an important service for the whole Internet community: it completes the information given by MX resource record and it allows to produce clean addresses when messages are exchanged among the Internet RFC822 world and the X.400 one (both Internet and Public X.400 service providers). A first experiment in using the DNS without expanding the current set of RR and using available ones was in the mean time deployed by some of the authors. The existing PTR resource records were used to store the mapping rules, and a new DNS tree was created under the ".it" top level domain. The result of the experiment was positive, and a fewShow full document text