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diff --git a/doc/rfc/rfc1486.txt b/doc/rfc/rfc1486.txt new file mode 100644 index 0000000..09ad1ce --- /dev/null +++ b/doc/rfc/rfc1486.txt @@ -0,0 +1,787 @@ + + + + + + +Network Working Group M. Rose +Request for Comments: 1486 Dover Beach Consulting, Inc. + C. Malamud + Internet Multicasting Service + July 1993 + + + An Experiment in Remote Printing + +Status of this Memo + + This memo defines an Experimental Protocol for the Internet + community. It does not specify an Internet standard. Discussion and + suggestions for improvement are requested. 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 .......................................... 1 + 1.1 The Advantage of a General-Purpose Infrastructure..... 2 + 2. Procedure ............................................. 2 + 2.1 Naming, Addressing, and Routing ...................... 3 + 2.2 The application/remote-printing Content-Type ......... 4 + 2.3 Usage Example ........................................ 5 + 2.4 Remote Printing without MIME ......................... 6 + 3. The Experiment ........................................ 7 + 3.1 Infrastructure ....................................... 8 + 3.1.1 Zones .............................................. 8 + 3.1.2 MX records ......................................... 8 + 3.2 Accounting and Privacy ............................... 9 + 3.3 Mailing list ......................................... 9 + 3.4 Prototype Implementation ............................. 10 + 4. Future Issues ......................................... 11 + 5. Security Considerations ............................... 11 + 6. Acknowledgements ...................................... 11 + 7. References ............................................ 11 + 8. Authors' Addresses..................................... 12 + A. The image/tiff Content-Type .......................... 13 + B. Uniform Addressing ................................... 13 + +1. Introduction + + Although electronic mail is preferable as a means of third-party + communication, in some cases it may be necessary to print + information, in hard-copy form, at a remote location. The remote + output device may consist of a standard line printer, a printer with + + + +Rose & Malamud [Page 1] + +RFC 1486 An Experiment in Remote Printing July 1993 + + + multiple fonts and faces, a printer that can reproduce graphics, or a + facsimile device. Remote output may be accompanied by information + that identifies the intended recipient. This memo describes a + technique for "remote printing" using the Internet mail + infrastructure. In particular, this memo focuses on the case in + which remote printers are connected to the international telephone + network. Furthermore, it describes an experiment in remote printing. + +1.1. The Advantage of a General-Purpose Infrastructure + + The experiment in remote printing is about "outreach"; specifically, + integrating the e-mail and facsimile communities. By providing easy + access to remote printing recipients, enterprise-wide access is + enhanced, regardless of kind of institution (e.g., commercial, + educational, or government), or the size of institution (e.g., + global, regional, or local). This approach at outreach allows an + organization to make it easier for the "outside world" to communicate + with the personnel in the organization who are users of facsimile but + not e-mail; e.g., the sales person, the university registrar, or the + (elected) official. The ease in which the Internet mail + infrastructure can be used to provide this facility is (yet) another + example of the power of a general-purpose infrastructure. + +2. Procedure + + When information is to be remotely printed, the user application + constructs an RFC 822 [1] message, containing a "Message-ID" field + along with a "multipart/mixed" content [2] having two parts, the + first being a "application/remote-printing" content-type, and the + second being an arbitrary content-type corresponding to the + information to be printed. The message is then sent to the remote + printer server's electronic mail address. + + It should be noted that not all content-types have a natural printing + representation, e.g., an "audio" or "video" content. For this + reason, the second part of the "multipart/mixed" content should be + one of the following: + + text/plain, message/rfc822, application/postscript image/tiff + (defined in Appendix A), any multipart + + Note that: + + (1) With the "text/plain" content-type, not all character sets may + be available for printing. + + (2) With the "message" content-type, the subordinate content will be + processed recursively. + + + +Rose & Malamud [Page 2] + +RFC 1486 An Experiment in Remote Printing July 1993 + + + (3) With the "application/postscript" content-type, the remote + printer server should evaluate the contents in a safe execution + environment. + + (4) With the "multipart" content-type the subordinate contents will + be processed recursively: for a "multipart/mixed" or + "multipart/digest" content, each subordinate content will start + on a new page, whilst for a "multipart/parallel" content, all + subordinate contents will, if possible, start on the same page. + Naturally, when processing a "multipart/alternative" content, + only one subordinate content will be printed. + + When the remote printer server finishes its processing, a message is + returned to the originator, indicating either success or failure. + +2.1. Naming, Addressing, and Routing + + A printer is identified by a telephone number which corresponds to a + G3-facsimile device connected to the international telephone network, + e.g., + + +1 415 968 2510 + + where "+1" indicates the IDDD country code, and the remaining string + is a telephone number within that country. This number is used to + construct the address of a remote printer server, which forms the + recipient address for the message, e.g., + + remote-printer@0.1.5.2.8.6.9.5.1.4.1.tpc.int + + That is, the local-part of the remote printer server's address is + ALWAYS "remote-printer", and the domain-part is constructed by + reversing the telephone number, converting each digit to a domain- + label, and being placed under "tpc.int." + + The message is routed in exactly the same fashion as all other + electronic mail, i.e., using the MX algorithm [3]. Since a remote + printer server might be able to access many printers, the wildcarding + facilities of the DNS [4,5] are used accordingly. For example, if a + remote printer server residing at "dbc.mtview.ca.us" was willing to + access any printer with a telephone number prefix of + + +1 415 968 + + then this resource record might be present + + *.8.6.9.5.1.4.1.tpc.int. IN MX 10 dbc.mtview.ca.us. + + + + +Rose & Malamud [Page 3] + +RFC 1486 An Experiment in Remote Printing July 1993 + + + Naturally, if several remote printer servers were willing to access + any printer in that prefix, multiple MX resource records would be + present. + + It should be noted that the presence of a wildcard RR which matches a + remote printer server's address does not imply that the corresponding + telephone number is valid, or, if valid, that a G3-facsimile device + is connected at the phone number. + +2.2. The application/remote-printing Content-Type + + (1) MIME type name: application + + (2) MIME subtype name: remote-printing + + (3) Required parameters: none + + (4) Optional parameters: none + + (5) Encoding considerations: 7bit preferred + + (6) Security considerations: none + + The "application/remote-printing" content-type contains originator + and recipient information used when generating a cover sheet. Using + the ABNF notation of RFC 822, the syntax for this content is: + + <content> ::= <recipient-info> CRLF + <originator-info> + [CRLF <cover-info>] + + <recipient-info> ::= "Recipient" ":" <value> CRLF + <address-info> + <originator-info> ::= "Originator" ":" <value> CRLF + <address-info> + + <address-info> ::= ["Title" ":" <value> CRLF] + ["Department" ":" <value> CRLF] + ["Organization" ":" <value> CRLF] + ["Mailstop" ":" <value> CRLF] + ["Address" ":" <value> CRLF] + ["Telephone" ":" <value> CRLF] + "Facsimile" ":" <value> CRLF + ["Email" ":" <value> CRLF] + <value> ::= *text + [CRLF LWSP-char <value> ] + + <cover-info> ::= *(*text CRLF) + + + +Rose & Malamud [Page 4] + +RFC 1486 An Experiment in Remote Printing July 1993 + + + Note that the value of the "Email" field is an RFC 822 mailbox + address. + +2.3. Usage Example + + Suppose someone wished to send the author some comments on this memo + using this facility. The message constructed might look like this: + + To: remote-printer@0.1.5.2.8.6.9.5.1.4.1.tpc.int + From: "John Q. Public" <jpublic@tpd.org> + Date: Sun, 11 Apr 1993 20:34:13 -0800 + Subject: Comments on "An Experiment in Remote Printing" + Message-ID: <19930411203413000.456@tpd.org> + MIME-Version: 1.0 + Content-Type: multipart/mixed; + boundary="----- =_aaaaaaaaaa0" + + ------- =_aaaaaaaaaa0 + Content-Type: application/remote-printing + + Recipient: Marshall Rose + Title: Principal + Organization: Dover Beach Consulting, Inc. + Address: 420 Whisman Court + Mountain View, CA 94043-2186 + US + Telephone: +1 415 968 1052 + Facsimile: +1 415 968 2510 + + Originator: John Q. Public + Organization: The Public Domain + Telephone: +1 801 555 1234 + Facsimile: +1 801 555 6789 + EMail: "John Q. Public" <jpublic@tpd.org> + + Any text appearing here would go on the cover-sheet. + + ------- =_aaaaaaaaaa0 + Content-Type: text/plain; charset="us-ascii" + + Here are my comments on your draft. + + ... + + ------- =_aaaaaaaaaa0-- + + + + + + +Rose & Malamud [Page 5] + +RFC 1486 An Experiment in Remote Printing July 1993 + + +2.4. Remote Printing without MIME + + If the originator's user agent doesn't support MIME, (e.g., the + originator accesses the Internet mail infrastructure via a gateway in + another mail dominion), then it is still possible for remote printing + to occur, albeit in a more limited fashion. Specifically, because a + "application/remote-printing" content is not present, cover sheet + information must be derived from some other source; and, the message + body will be treated as a "text/plain" content. + + Typically, a cover sheet consists of three sections: + + o information identifying the originator; + + o information identifying the recipient; and, + + o additional information supplied by the remote printer server. + + To identify the originator, the remote printer server will use the + message headers, usually by stripping any trace headers (i.e., + "Received" and "Return-Path") and then re-ordering the remaining + headers starting with the "From" header. + + To identify the recipient, an alternative syntax is used for + recipient addressing, in which the local-part of the remote printer + server's address consists of "remote-printer" followed by an RFC 822 + atom, e.g., + + remote-printer.Arlington_Hewes/Room_403@0.1.5.2.8.6.9.5.1.4.1.tpc.int + + This mailbox syntax is purposefully restricted in the interests of + pragmatism. + + The atom following "remote-printer" is considered an opaque string + for use in recipient identification when generating a cover sheet. + + To paraphrase RFC 822, an atom is defined as: + + atom = 1*atomchar + + atomchar= <any upper or lowercase alphabetic character (A-Z a-z)> + / <any digit (0-9)> + / "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+" + / "-" / "/" / "=" / "?" / "^" / "_" / "`" / "{" + / "|" / "}" / "~" + + When generating a cover sheet using this opaque string, the remote + printer server will interpret an underscore character ("_") as a + + + +Rose & Malamud [Page 6] + +RFC 1486 An Experiment in Remote Printing July 1993 + + + space, and a solidus character ("/") as an end-of-line sequence. A + remote printer server will interpret two consecutive underscore + characters in the opaque string as a single underscore, and two + consecutive solidus characters as a single solidus. So, the opaque + string, + + Arlington_Hewes/Room_403 + + used in the example above might appear on the cover sheet as + + To: Arlington Hewes + Room 403 + + Note that some Internet mail software (especially gateways from + outside the Internet) impose stringent limitations on the size of a + mailbox-string. Thus, originating user agents should take care in + limiting the local-part to no more than 70 or so characters. + + Note that by using the alternative syntax for recipient addressing, + it is completely legal to send non- textual messages in which the + cover sheet information is automatically derived -- simply by + including "MIME-Version:" and "Content-Type:" headers in the message, + but omitting the initial "application/remote-printing" content, e.g., + +To: remote-printer.Arlington_Hewes/Room_403@0.1.5.2.8.6.9.5.1.4.1.tpc.int +cc: Marshall Rose <mrose@dbc.mtview.ca.us> +From: Carl Malamud <carl@malamud.com> +Date: Sun, 18 Jul 1993 09:14:13 -0500 +Subject: proposal for enhancement +Message-ID: <19930718141413000.123@malamud.com> +MIME-Version: 1.0 +Content-Type: application/postcript + +%! + + Note that by using the alternative syntax for recipient addressing, + remote printing and e-mail recipients can be identified in the same + message. + +3. The Experiment + + In order to gain experience with this style of remote printing, an + experiment is underway. + + + + + + + + +Rose & Malamud [Page 7] + +RFC 1486 An Experiment in Remote Printing July 1993 + + +3.1. Infrastructure + + The domain "tpc.int." is being populated in order to provide the MX- + based infrastructure for routing to a remote printer server. In + order to facilitate distributed operations, this domain is divided + into a zone for each IDDD country code. Sites participating in the + experiment contact the appropriate zone administrator in order to be + listed, by examining the SOA resource record associated with the + zone. For example, a site in the Netherlands (IDDD country code 31) + would contact the zone administrator for the domain "1.3.tpc.int." in + order to be listed, e.g., + + % dig 1.3.tpc.int. soa + + Each zone administrator has a simple set of procedures for listing a + participant. For example, in the US (IDDD country code 1), + participating sites send an "exchange file" to the administrator, + which indicates the prefixes that the site wishes to list. The zone + administrator for the domain "1.tpc.int." merges the exchange files + from all participating sites to create a zone for each area code. + These zones are then replicated using the normal DNS zone transfer + procedures. + +3.1.1. Zones + + It should be noted that zones under "tpc.int" are created on the + basis of IDDD country codes and area codes; they are not created for + each subdomain. For example, in the US and Canada (IDDD country code + 1), no more than one zone is allocated for each area code. In + contrast, for countries with a smaller numbering plan, only a single + zone, for the whole country would be allocated. For example, if Fiji + (IDDD country code 679), were to join the experiment, then it is + likely that a single zone would be added to the DNS, i.e., + "9.7.6.tpc.int." + +3.1.2. MX records + + The MX records present in a zone can have an arbitrary level of + precision. For example, the North American Numbering Plan (IDDD + country code 1) is structured by a 3-digit area code, followed by a + 3-digit exchange prefix, followed by a 4-digit station number. As + such, one might expect that MX records in this zone would be similar + to + + *.5.1.4.1.tpc.int. IN MX 10 dbc.mtview.ca.us. + + + + + + +Rose & Malamud [Page 8] + +RFC 1486 An Experiment in Remote Printing July 1993 + + + which accessed any printer with a telephone number prefix of + + +1 415 + + (i.e., allowing access to any printer in area code 415), or might be + similar to + + *.8.6.9.5.1.4.1.tpc.int. IN MX 10 dbc.mtview.ca.us. + + (i.e., allowing access to any printer in area code 415, exchange + prefix 968). + + However, the level of precision is arbitrary. For example, if all of + the printers in an organization had a telephone number prefix of + + +1 415 96 + + then an MX record such as + + *.6.9.5.1.4.1.tpc.int. IN MX 10 dbc.mtview.ca.us. + + could be used. + +3.2. Accounting and Privacy + + There is no accounting nor settlement in the experiment; however, + participating sites may implement access control to prevent abuse. + Records may be kept for auditing purposes; however, the privacy of a + participant's printing should be honored. As such, any auditing + should contain at most this information: + + o the date the message was received; + + o the "From" and "Message-ID" fields; + + o the size of the body; + + o the identity (telephone number) of the printer; + + o any telephony-related information, such as call duration; + and, + + o any G3-related information, such recipient ID. + +3.3. Mailing list + + There is a mailing list for the experiment. Interested readers + should send a note to: + + + +Rose & Malamud [Page 9] + +RFC 1486 An Experiment in Remote Printing July 1993 + + + tpc-rp-request@aarnet.edu.au + + and ask to subscribe to the + + tpc-rp@aarnet.edu.au + + list. + +3.4. Prototype Implementation + + A prototype implementation is openly available. The MIME + instructions for retrieval are: + + MIME-Version: 1.0 + Content-Type: multipart/alternative; + boundary="----- =_aaaaaaaaaa0" + Content-Description: pointers to ftp and e-mail access + + ------- =_aaaaaaaaaa0 + Content-Type: message/external-body; + access-type="mail-server"; + server="archive-server@ftp.ics.uci.edu" + + Content-Type: application/octet-stream; type="tar"; + x-conversions="x-compress" + Content-ID: <4599.735726126.1@dbc.mtview.ca.us> + + mimesend mrose/tpc/rp.tar.Z + + ------- =_aaaaaaaaaa0 + Content-Type: message/external-body; + access-type="anon-ftp"; name="rp.tar.Z"; + directory="mrose/tpc"; site="ftp.ics.uci.edu" + + Content-Type: application/octet-stream; type="tar"; + x-conversions="x-compress" + Content-ID: <4599.735726126.2@dbc.mtview.ca.us> + + ------- =_aaaaaaaaaa0-- + + This package contains software for UNIX-based systems, and was + developed and tested under SunOS, with an openly-available facsimile + package (Sam Leffler's FlexFAX package), and contains information for + sites acting as either client or server participants, and zone + administrators. + + + + + + +Rose & Malamud [Page 10] + +RFC 1486 An Experiment in Remote Printing July 1993 + + +4. Future Issues + + The experiment in remote printing described herein does not address + several issues, e.g., + + o determining which content-types and character sets are + supported by a remote printer server; + + o introduction of authentication, integrity, privacy, + authorization, and accounting services; + + o preferential selection of a remote printer server; and, + + o aggregation of multiple print recipients in a single + message. + + Initially, the experiment will not address these issues. However, + subsequent work might consider these issues in detail. + +5. Security Considerations + + Internet mail may be subject to monitoring by third parties, and in + particular, message relays. + +6. Acknowledgements + + Carl Malamud of the Internet Multicasting Service provided + substantive comments on the design of the experiment. Douglas Comer + of Purdue, Daniel Karrenberg of RIPE, Sam Leffler of SGI, Paul + Mockapetris of ARPA, also provided comments. + +7. References + + [1] Crocker, D., "Standard for the Format of ARPA Internet Text + Messages", STD 11, RFC 822, UDEL, August, 1982. + + [2] Borenstein, N., and N. Freed, "MIME: Mechanisms for Specifying + and Describing the Format of Internet Message Bodies", RFC 1341, + Bellcore, Innosoft, June 1992. + + [3] Partridge, C., "Mail Routing and the Domain System", RFC 974, + CSNET CIC BBN, August 1982. + + [4] Mockapetris, P., "Domain Names -- Concepts and Facilities", STD + 13, RFC 1034, USC/Information Sciences Institute, November 1987. + + + + + + +Rose & Malamud [Page 11] + +RFC 1486 An Experiment in Remote Printing July 1993 + + + [5] Mockapetris, P., "Domain Names -- Implementation and + Specification", STD 13, RFC 1035, USC/Information Sciences + Institute, November 1987. + +8. Authors' Addresses + + Marshall T. Rose + Dover Beach Consulting, Inc. + 420 Whisman Court + Mountain View, CA 94043-2186 + US + + Phone: +1 415 968 1052 + Fax: +1 415 968 2510 + EMail: mrose@dbc.mtview.ca.us + + + Carl Malamud + Internet Multicasting Service + Suite 1155, The National Press Building + Washington, DC 20045 + US + + Phone: +1 202 628-2044 + Fax: +1 202 628 2042 + EMail: carl@malamud.com + + + + + + + + + + + + + + + + + + + + + + + + + +Rose & Malamud [Page 12] + +RFC 1486 An Experiment in Remote Printing July 1993 + + +Appendix A. The image/tiff Content-Type + + (1) MIME type name: image + + (2) MIME subtype name: tiff + + (3) Required parameters: none + + (4) Optional parameters: none + + (5) Encoding considerations: base64 + + (6) Security considerations: none + + (7) Published specification: TIFF class F, as defined in: + + Tag Image File Format (TIFF) revision 6.0 + + Developer's Desk Aldus Corporation 411 First Ave. South Suite + 200 Seattle, WA 98104 206-622-5500 + +Appendix B. Uniform Addressing + + A user may choose to include several recipients in a message, one or + more of which may be recipients reached via remote printing. + However, the message format accepted by a remote printer server + contains only a single recipient. + + There are three solutions to this problem: first, during composition, + a "smart" user agent can determine that one or more remote printing + recipients are present, and submit the appropriate messages. This + has the disadvantage that the submission for the e-mail recipients + does not contain any information about the remote-printing + recipients. + + A second solution is to use the alternative syntax for recipient + addressing described in Section 2.4 -- however, this minimizes useful + information available when constructing the cover sheet. + + A third solution is for a site participating as a client to offer a + remote printing recipient exploder server to its users. Each remote + printing recipient is assigned a mailbox relative to the exploder, + and, as such, appears as an "ordinary" e-mail address. Using this + strategy, the user agent has no knowledge of which recipients are + accessible via e-mail or remote-printing -- the user simply specifies + a collection of mailbox recipients. Those recipients which are + accessible via remote-printing are automatically routed to the + exploder. For each recipient in the envelope, a local database is + + + +Rose & Malamud [Page 13] + +RFC 1486 An Experiment in Remote Printing July 1993 + + + consulted to retrieve addressing information for the recipient, and a + message is submitted to the appropriate remote printer server. + +For example, if the original message submitted was: + + To: mrose@rpexplode.tpd.org + cc: Arlington Hewes <tpcadmin@dbc.mtview.ca.us> + From: "John Q. Public" <jpublic@tpd.org> + Date: Sun, 11 Apr 1993 20:34:12 -0800 + Subject: Comments on "An Experiment in Remote Printing" + Message-ID: <19930411203412000.123@tpd.org> + MIME-Version: 1.0 + Content-Type: text/plain; charset=us-ascii + + Here are my comments on your draft. + ... + + then the first recipient, "mrose@rpexplode.tpd.org", would be routed + to an remote printing exploder, which would submit the message shown + in the example in Section 2.3. The second recipient, + "tpcadmin@dbc.mtview.ca.us", would receive the message shown here. + Note that a reply by this recipient could include the remote printing + recipient. + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Rose & Malamud [Page 14] +
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