tomw@ccadfa.adfa.oz.au (Tom Worthington) (03/08/91)
XMAIL": Proposal for an Electronic Mail Option to be Added to CCITT Group 3 Facsimile Standard by Tom Worthington I propose that an option, called "FaxMail", be provided for Group 3 facsimile machines to exchange electronic mail. This could later be expanded to allow these machines to interface with X.400 electronic mail and X.500 directory systems. The large number of existing computer - facsimile interfaces can be upgraded to provide an electronic mail option at minimal cost. This would encourage the widespread adoption of electronic mail, which will otherwise not occur. Facsimile versus electronic mail Group 3 facsimile machines are widespread and popular. In comparison computer based electronic mail has not been a successful product. The CCITT X.400 standard corrects one major problem of electronic mail systems: the lack of standardisation. A number of other problems remain with X.400, particularly for single users. As a result X.400 is unlikely, in its current form, to reach the level of use of facsimile. I suggest that the needs of single users are crucial to a product such as electronic mail. The per-user cost of installing X.400 electronic mail for a site with a large number of computer users is low. However it is likely that only a few users in an organisation will be initially interested in using the electronic mail service. Therefore the cost of installing the electronic mail system must be justified for those few users. This is limiting the adoption of electronic mail. Facsimile has advantages for single users: it can be installed by the user, it has a low installation cost, it can transmit graphics and is simple to use. Facsimile suffers from a number of limitations: it is point to point only, has no directory service and does not transmit documents which can be edited. Computer based electronic mail systems can provide services facsimile cannot, such as broadcast services, on-line directory and documents which can be edited. However electronic mail suffers from a number of limitations for individual users: it cannot be installed by the user, has a high start-up cost, is difficult to maintain and cannot (in many implementations) transmit graphics. Current international standards allow for facsimile to be interfaced to X.400 electronic mail systems. In effect facsimile is being incorporated into the electronic mail standard. I suggest that the reverse is more appropriate to the user: that electronic mail be incorporated into facsimile. The current proposals for electronic mail do not address the needs of small scale users. A previous example of an electronic mail product which failed to take into account the needs of the user was Teletex. As a result this product failed in the Australian market. Current proposals for X.400 electronic mail will fail similarly. Build on existing facsimile - computer installed base There are now a large number of computer - facsimile interface devices being installed. These provide for documents to be transformed into an image and transmitted as a facsimile, without the use of paper as an intermediary step. They can also receive images from a conventional facsimile machine and store them as a computer file. The interface software runs in "background" on the host computer. It can therefore transmit and receive facsimiles at any time, without interrupting other work. The hardware of a facsimile interface provides a 9600 baud modem. The software provides control of the modem for sending and receiving documents without user intervention. All that need be added to provide a useful electronic mail service is a standard protocol. The Group 3 Facsimile standard provides for optional features. Facsimile machines go through a hand-shaking session when they connect to find out what options they have in common. Electronic mail could be simply added as an extra option. Users of suitably equipped facsimile interfaces would have the extra electronic mail options available when sending to similarly equipped devices. In all other respects the facsimile interfaces would operate as at present. The use of computer facsimile interfaces and the facsimile standard provides a better chance for the widespread introduction of electronic mail than current X.400 proposals. The current installed base of computer facsimile interfaces could have electronic mail added at minimal COSt, with only a software change. This form of electronic mail would be attractive to new users as well as existing computer facsimile users. It could be installed by the user, low cost and immediately useable with all existing group 3 facsimile machines. Where the user requires additional facilities, these systems can be interfaced to an X.400 electronic mail bureau. This will allow facilities such as store and forward of messages, broadcast, sender/receiver identification and directory services to be available to those users who required them. This will provide the large population of customers which X.400 needs to become a viable service. Implementation An electronic mail facility would be added to the Group 3 facsimile standard allowing messages to be exchanged between machines using the public switched telephone network at up to 9600 baud. No prior approval or registration would be required. Messages formats would be similar to those for X.400 messages. The initial message formats implemented would be text messages, binary data and images (using the group 3 facsimile format). The service would include error correction. Other formats and services such as compound documents, electronic data interchange and public key encryption could be added later. Mail could be addressed to a particular sub-address within a facsimile machine. This would allow for one facsimile interface to be shared on a multi-user system. The facsimile machine's "terminal identifier" could be expanded to provide X.400 standard addresses. With such a scheme a system would learn addressing information as it was used. The user would be required to enter a telephone number the first time a particular machine was called. The user's system could "learn" addressing information from the other machine during the call, for future reference. The user could then address subsequent calls using details such as organisation or individual's name. The telephone number would only need to be entered by the user again if it was changed. Existing facsimile facilities could be enhanced with an electronic mail option. For example the option for polling could be implemented for electronic mail. The ability to set up a network of facsimile machines which can store and forward messages could also be implemented. Advanced applications Low cost dial-up electronic mail could provide an alterative to local and wide area networks for some applications. Computer files could be transmitted over electronic mail and documents printed by addressing mail to an attached printer. Computer database applications could be updated and queried via electronic mail messages, using an electronic data interchange format. Organisations could use their existing internal telephone network for low volume electronic mail communications at little extra cost. Where automatic fax - telephone switches are used, an extra telephone line would not be required. These facilities could be provided by any electronic mail software using conventional data modems. However computer - facsimile interfaces are especially suited to adoption to electronic mail. Facsimile modems are half duplex, they transmit data in one direction at 9600 baud and in the other at 300 baud. This is a disadvantage where the modem is used for interactive terminal sessions. However it is ideal for sending electronic mail in one direction, with only a small amount of error correction information being sent in the other direction. "With FaxMail they can have the combined benefits of electronic mail and facsimile services" There are a large number of personal computer users who would use electronic mail if they could obtain it as simply and cheaply as facsimile. With FaxMail they can have the combined benefits of electronic mail and facsimile services. Tom Worthington MACS PO Box 13 Belconnen ACT 2617 E-Mail: ACSnet: tomw@adfa.oz.au 16 December, 1990 Copyright Australian Computer Society Inc. 1991 Published in the Canberra Branch Newsletter, February 1991 edition
hrs1@cbnewsi.att.com (herman.r.silbiger) (03/09/91)
I will summarize the long submission to which my comment is directed. The author proposes that fax be used as an X.400 e-mail facility, by giving it the capability to exchange text and binary files, and some other optional facilities. What the author is proposing has almost already been accomplished. CCITT has agreed that Group 3 fax should be able to have a file transfer mode, as well as a character mode. The file transfer mode was originally submitted by the US, and is called BFT (Binary File Transfer). The coding rules for BFT are technically aligned with FTAM (ISO 8751). Not all of the FTAM attributes are supported, and some additional non-FTAM attributes have been added. In addition, a DFT, Document File Transfer, proposal from the French will be added for ASCII documents, and an EDI file tranfer as well. The above methods all transfer files, which have to be interpreted externally to the fax after reception. The Character Mode in fax will transfer characters rather than pels. It requires a character generator in the fax terminal, but allows the use of the fax terminal's print engine. It also allows, on a part or whole page basis, the intermixing of character and image (pel) information. These enhancements to group 3 fax will likely be approved by Spring 1992. There is also a submission to the CCITT Study Group VIII meeting 18-27 March in Geneva from AT&T concerning access of G3 fax terminals to enhanced services. A method is proposed for adding an information file to the fax transmission which communicate address and service element information when fax terminals access services such as X.400 MHS. Herman Silbiger hsilbiger@attmail.com