Telecom Paris


Motivation for the Majordomo Project

Time and space asynchronous personal communication is achieved by various means: surface, electronic, voice and fax mail. However, those means are not equivalent in their usefulness. For example, surface mail can be used to transmit nearly every type of information (boulders, disks, photos), but also takes a long time to reach the recipient. On the other hand, electronic, voice and fax mail are most of the time near real time, i.e. that there is no delay of hours or even days until the information reaches the recipient. Voice mails and faxes and e-mails, respectively, have different areas of use. While it is easy to transmit some pages of source code via e-mail or even fax (although OCR or typing has to be used to be able to use the code and not just look at it), or to transfer a file using e-mail, it is not possible to transfer voice by fax or to visualize something by phone.
But, as versatile as fax and especially electronic mail may be, there is still a problem accessing the information. Not everybody owns a PDA (Personal Digital Assistant) capable of connecting to one's mailbox via cellular phone, and, even worse, one is not always physically close to the fax machine to look at the received faxes. On the other hand, it just takes a simple (public) phone to access an answering machine in any spot on the world and to be up to date about the latest calls. Hence, the thought of developing an "answering machine", that is not only capable of storing voice calls, but as well can be used to store and access e-mails and received faxes, came up.
Some interests in this project, called "Majordomo" from now on, are, amongst others:
Furthermore, it is thought of developing a client software that permits access to Majordomo on a HTTP/HTML basis, so that the information can be retrieved from an Internet account as well.
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Hardware and Software

It was clear from the beginning that the use of an ISDN board would be crucial to the success of majordomo, because it is very likely that a fax and a voice message might reach the PC at the same time. Since every standard ISDN board is capable of handling two channels (and therefore two incoming calls) at a time, this problem was solved easily by giving different numbers to the different services, i.e. one number for voice messages, one for faxes and a third one for getting access to the current accounts. Another great advantage of ISDN boards is the fact that multiple applications can gain access to them, so that the Majordomo server will not prevent other applications on the same computer, like dial-up networking or terminal programs for bbs-systems, from running.
The ISDN board is programmed using Microsoft Visual C++ 5.0 Professional and the CAPI, the Common ISDN Application Programming Interface, a now widely acccepted and OS independant standard for developing applications for ISDN boards. The problem is, of course, that this limits Majordomo to some lowest common denominator, i.e. that features like call redirection might not be accessible using this kind of API. Anyway, this approach is far better than writing a program for especially one card and thus limiting the possible equipment on the target server.
No decision has yet been made about the language that is going to be used for the client software, since it may be a very convenient, time and cost saving way to write this client software using Java, but some requirements for the client are not yet met by the Java language, such as OS independent audio recording.
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Inner Workings of Majordomo

How is Majordomo supposed to do his work ? An example: company C set up the Majordomo server properly on a PC, assigning it the phone number x01 for incoming phone calls, x02 for incoming fax messages and x03 for requests by users that have an account for the majordomo server. In addition to that, the PC is connected to the company wide intranet. Let's assume person A wants to call person Z, who has an account for the Majordomo. The call to number x01, is made according to the ISDN protocoll, and after it is picked up, A is asked by Majordomo to give her name and the name of the call's recipient. This information is used to determine the correct account by speech recognition and to inform Z that she received a call from A. Then, after the call has been recorded, it is placed into Z's account. At the same time, B sends a fax to the Majordomo server, thus dialing x02. She indicates Z as the recipient on the cover sheet, and Majordomo finds out about the correct account, this time using OCR.
Finally, Z calls from her vacation to find out who tried to reach her in the mean time. She dials the number of Majordomo with the trailing 03, and then is asked by Majordomo to give her name and her password. The caller is then verified first by her password (speech recognition) and afterwards by her voice (speaker verification). When Z passes both test, Majordomo tells her that she received a voice message from A and a fax from B. She now can ask Majordomo to read the messages to her, to read just the first n lines or the subject, to delete the messages or to forward them to someone else. If Z can not understand the name of the sender, be it because the sender did not speak very clearly or because the sender is unknown, Z can also ask Majordomo to spell the name.
Z also has the possibility to access his account using the client software. This would require her to give her login, then the password would be recorded by the client and send to the server to verify the user. When access is granted, Z can get the latest updates on her account, again seeing that she received one voice and on fax message, and beeing able to actually look at them.
Of course, all this can be done with e-mails as well, and it is also thought of implementing Multicast IP into the Majordomo project. A coverage of this will soon follow.
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Related Links

There are already some commercial applications implemeting this way of information management. For further information, please have a look at the following sites:
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© by Achim J. Latz, 31/07/1998