|Voice And Fax Messaging In An Internet
BRIAN DANIELS & MEI-JEAN GOH
In today's business world, voice mail boasts an installed base of over 10 million
mailboxes and 500,000 systems. It is commonplace for people to leave a voice message when
a phone call goes unanswered or a line is busy. Somewhat less common is the process of
intentionally composing and sending a voice message in the first place, like we do when
exchanging e-mail messages. While this option is currently available, it's usually within
an enterprise and only for messages between colleagues who share the same PBX or key
system, share the same voice mail system, and likely work in the same building. Less
common still is the ability to intentionally direct a voice message to someone served by a
separate -- and possibly distant -- voice mail system.
In the past, vendors of voice mail equipment have responded to this desire for
intersystem communication by devising three approaches to voice message networks:
Proprietary Methods and Protocols
Most major suppliers of voice mail systems offer proprietary ways of delivering voice
messages between their systems. But try linking with a voice mail system from another
vendor, and you're out of luck.
Standard Analog Voice Message Networking
Audio Messaging Interchange Specification -- Analog (AMIS-A): This is a method that relies
on telephone channels for connection.
Standard Digital Voice Message Networking
Audio Messaging Interchange Specification -- Digital (AMIS-D): This method is based on the
International Telecommunication Union's (ITU) X.400 series of messaging recommendations.
All in all, networking dispersed voice mail systems has been possible for some time,
but the technology has been limited.
Next to leaving a voice message, we could always turn to faxing. Almost as ubiquitous
as voice mail, there are 40 million fax machines in the world today spitting out a huge
chunk of our communications traffic. This is also taking a huge piece of the
communications budget, with fax traffic costing approximately $45 billion each year.
Along comes the Internet revolution. It is currently estimated that 57 million people
have access to the Internet. And what's at the top of their lists while on the net?
E-mail. There are 188 million electronic mail boxes on the net - and that figure is
growing at a rate of 10 percent each year. So, with this Internet explosion, it seemed
certain that voice mail and faxes would be relegated to the status of messaging orphans.
Voice Profile for Internet Mail (VPIM) brings voice and fax into the family of Internet
messaging technology. Intentional messaging is a good thing: Universal intentional
messaging is even better. The Internet exemplifies universality in communications. The
Voice Profile has resulted from the desire to build out the global Internet mail facility
to include voice and fax message exchanges.
VPIM sprang from the collaboration of voice mail vendors working within the Electronic
Messaging Association (EMA), a 700-member trade association of electronic messaging users,
equipment vendors, and service suppliers. A working group of vendors showcased operating
VPIM prototypes at the EMA's April 1996 annual convention, and followed with product
demonstrations the next year. VPIM, based on Internet e-mail standards, is intended to be
very much an Internet standard. At this time in 1998, it is on the standards track of the
Internet Engineering Task Force (IETF), currently at the level of proposed standard.
Consider the benefits of what VPIM enables: Universal, intentional voice and fax
Intentional messaging means deliberately leaving someone a message instead of placing a
phone call, and then only leaving a message if you can't connect directly with the person
called. Intentional messaging elevates voice mail technology from an erstwhile role as an
answering machine to the status of effective business tool and productivity expander. Why?
Reflect on these business scenarios:
- Jeff wants to let Kelly know that this afternoon's meeting is postponed to four o'clock.
He knows that if he calls Kelly, Kelly will likely want to discuss the budget matter.
There goes twenty minutes. If he can intentionally deliver a message, Jeff needn't risk
losing the twenty minutes.
- Jeff wants to thank the salespeople in the southeast region. A personal message in his
own voice is good form. Trouble is, there are two hundred salespeople. Instead, Jeff
records a sincere message, addresses it to the southeast distribution list (much the same
as he would address a group e-mail) and five minutes later is on his way to the golf
course with hours of time saved.
- Before he leaves, Jeff needs to send one last message - to Todd - to remind him of
dinner with the fundraisers that evening. Jeff knows that Todd could never find tonight's
venue unless he draws Todd a map. Thanks to VPIM's inclusion of fax, he can do just that.
From his fax phone, Jeff records a reminder to Todd, and sends it along with a hastily
drawn map to Todd's mailbox.
HOW DOES IT WORK?
VPIM is a profile of accepted electronic mail standards and methods used on the
Internet, adapted and augmented for the requirements of voice mail. VPIM's immediate
foundations are the (Extended) Simple Mail Transfer Protocol (ESMTP) and the Multi-purpose
Internet Message Extensions (MIME) specifications. These in turn are built upon the
Transport Control Protocol/Internet Protocol infrastructures, which are the backbone of
the Internet and many corporate intranets.
The Simple Mail Transfer Protocol dates back to the early 1980s, and is the workhorse of
electronic messaging on the Internet. It lays out the dialog with which two disparate mail
systems converse with one another in order to transfer message content. Originally the
message content was (and even now remains), made up of pure and simple text characters.
Throughout the 1990s, the protocol has been extended in several ways to accommodate richer
messaging forms. These include providing notifications of message delivery, delivery of
non-text binary information, and more efficient carriage of large messages. VPIM takes
advantage of several extensions.
The Multi-purpose Internet Message Extensions (MIME) standards recognize the need to
include more than simple text within the content of electronic mail. The MIME standards
provide mechanisms for including various types of media - text, audio, image, video, and
application data such as work processing or spreadsheet documents - within an e-mail. A
VPIM voice message is a special type of MIME message.
The Voice Profile is more than voice. VPIM enables the Internet exchange of fax messages,
alone or accompanied by voice. Here again, VPIM has built upon an accepted standard, in
this case, the Tagged Image File Format (TIFF). TIFF has been an accepted standard in
desktop publishing for many years, and VPIM has moved a fax-oriented flavor of this,
TIFF-F, into the realm of Internet standards. VPIM gives businesses the ability to
exchange messages on the Internet in two of the more effective and widely used media.
ADDRESSING A VPIM MESSAGE
The VPIM specification is flexible concerning the way in which a message recipient is
addressed. However, certain vendors are adopting a strategy to enable users to address a
VPIM message with a mailbox number which is the same as the phone number you would use to
dial and talk to the owner of the mailbox. The number could be from an international
dialing plan, or a private-network numbering plan.
VPIM carries on the tradition of phone/extension number and voice mailbox address
commonality. This applies to private enterprise numbering plans, or public-number plans
that are consistent with the ITU's E.164 recommendation or the North American Numbering
Currently, VPIM servers need to locally store some information to derive the VPIM
server address of a message recipient based on the recipient's phone number. However, work
is underway within the EMA, IETF, and elsewhere to apply directory technology to voice
communications on the Internet. Standards work is already in progress to define schemas
(directory organizations) for use in VPIM address resolution. This is working towards an
eventual interlocking global grid of public and enterprise directory services that will be
a powerful enabler for universal VPIM messaging.
Voice messaging is a powerful productivity tool, especially when:
- It's done intentionally, and not merely as a resort to an unanswered call.
- It's universal - you can reach people anywhere, inside or outside of your organization.
- It's used just like e-mail.
- It's low cost, and avoids toll charges.
- It combines fax messaging as well.
The vehicle for delivering this powerful tool is the Internet and/or corporate
intranets, using messaging standards embodied in the Voice Profile for Internet Mail.
Brian Daniels is a development manager with Northern Telecom's (Nortel) Toronto
Multimedia Applications Center. Mei-Jean Goh is a development team leader with this Nortel
Enterprise Networks unit. The authors were responsible for the creation of Nortel's
Meridian Mail Net Gateway, one of the first commercial products to employ the Voice
Profile for Internet Mail standards. Nortel, a leading global provider of communications
network solutions, provides network and telecommunications equipment and related services
in North America, Caribbean and Latin America, Europe, the Middle East, and Asia/Pacific.
Nortel also provides products and services to the telecommunications and cable television
industries, businesses, universities, governments and other institutions worldwide.