The Hacker's Encyclopedia 1998/hackers_encyclopedia.iso/hacking/internet/i_phone.faq

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Archive-name: internet-services/voice-faq
Last-Modified: 1995/10/25
Version: 0.3

FAQ: How can I use the Internet as a telephone?
Version 0.3 - Oct 22 1995

* This is a DRAFT FAQ. This document is new and in transition. If you
notice that software for doing speech over the Internet is  missing from
this list, or information herein needs updating, please send e-mail to
[e-mail] *

This document is copyright 1995 by Kevin M. Savetz and Andrew Sears. All
rights reserved.  More legal stuff is near the end of this file.

*** TABLE OF CONTENTS
Can I use the Internet as a telephone?
   How does it work?
   What do I need to call others on the Internet?
   Is the sound quality as good as a regular telephone call?
   Is there a noticeable delay to hear the other user?
   What is the difference between full duplex and half duplex?
   What is multicasting?
   Can I talk to users across PC/Mac/Unix platforms?
   Can I talk to users of other phone software?
What software is available?
   For the Mac
      Maven
      NetPhone
      PGPfone
      CU-SeeMe
   For Windows
      Speak Freely
      CU-SeeMe
      Internet Phone
      DigiPhone
      Internet Global Phone
      WebPhone (vaporware)
      Internet Voice Chat (defunct)
   For UNIX
      Speak Freely
      CyberPhone
      NEVOT
      vat
      mtalk
      ztalk
What hardware is available?
   Jarba Earphone
   Sound Advantage
Legal Stuff
Where to Find this Document

*** CAN I USE THE INTERNET AS A TELEPHONE?
Yes. In recent months, several programs have become available that will
let you, equipped with the right computer hardware, an Internet
connection, and special software, to speak in real-time over the
Internet, using your own voice rather than by typing - in effect using
the network like a telephone.

Some of the programs available to do voice on the 'net is free, others
are commercial. Many of these products are ready for prime time, but
others are still very experimental.

+++ HOW DOES IT WORK?
It's magic! Audio conferencing programs work by digitizing your speech
as you talk and sending the digital data over the Internet. But there's
a problem: a typical modem connection has limited bandwidth - 14.4KBPS
modems can send and receive a maximum of 1,800 bytes of non-compressible
data each second. Telephone quality speech needs 8,000 bytes per second
of bandwidth. There are two solutions to the problem: get more
bandwidth, or compress the sound information before transmitting it.
Although both solutions are used, most programs compress the audio.

There are a variety of methods for encoding and compressing sound data,
and as you might expect, the standards aren't necessarily very standard,
yet. The quality of the audio you'll send and receive depends on the
application you're using, the speed of your computer and the compression
method used. In my tests, audio is usually understandable, albeit less
clear than a phone call. Still, talking across the country or around the
world for the cost of an Internet connection is kind of amazing, and
easy on the wallet.

You and the associate you are talking to need to be using software that
can transmit and receive the same protocol. That doesn't necessarily
mean you need the same software, or even the same type of computer. For
instance, the GSM protocol is pretty standard. However, some programs
can only use proprietary encoding methods, so they'll only communicate
with the same software on the other side of the wire. Standard
compression methods are:
     GSM: for more information: http://www.cs.tu-berlin.de/~jutta/toast.html
     CVSD
     RTP: Real Time Protocol

+++ WHAT DO I NEED TO CALL OTHERS ON THE INTERNET?
Besides the software, you will need an Internet connection  You'll also
need a fairly speedy computer (at least 25 MHz). Although the exact
specs vary from program to program, a Mac Classic or a PC XT generally
won't do the trick :-) Your computer will also need a sound card (for
PCs; Macs have built-in sound,) speakers and a microphone. All sound
cards will have a microphone jack in the back of them. Many Macs have
mic jacks. If yours doesn't, you'll need a serial Microphone, such as
MacRecorder or Sound Advantage.

If you connect to the Internet over a modem, you will need a SLIP or PPP
connection. The bare minimum for good quality sound is a 14.4k modem.
The quality of a 14.4k connection will depend largely on the software
and the error rate of your telephone line.  A 28.8k modem should give
excellent quality for most all applications.

+++ IS THE SOUND QUALITY AS GOOD AS A REGULAR TELEPHONE CALL?
Surprising to most people, if you have a good Internet connection then
the sound quality is comparable to a regular phone call. However the
sound quality varies dramatically between applications. In nearly all
cases, the limiting factor will not be the speed and capacity of the
Internet, but will depend on the local work at each end. If both parties
have fast network connections, some applications provide sound quality
significantly better than a regular telephone call because they use 16
bit signals rather than 8 bit signals in regular phone lines.

+++ IS THERE A NOTICEABLE DELAY TO HEAR THE OTHER USER?
The answer to this also depends on the application and users' Internet
connections. For most applications, you might notice a delay, but for
good connections it seems be in the range of .01-.05 seconds. A delay
over .05 seconds might be noticeable on the normal telephone system
because you will hear an echo, but calls over the Internet do not
produce an echo.

+++ WHAT IS THE DIFFERENCE BETWEEN FULL DUPLEX AND HALF DUPLEX?
In a full duplex conversation, you can speak and hear the other person
at the same time, like on the phone. In half duplex, only one person can
speak at once; if you speak while the other person speaks, then you will
not be able to hear each other. In these applications, you usually press
a button to speak. Most applications are starting to support both full
duplex and half duplex modes. Your sound card will either be full duplex
or half duplex, which will control which mode you can operate in.  Most
new Macs and many Unix stations come equipped with full duplex sound
cards, but most PC's do not.

+++ WHAT IS MULTICASTING?
Multicasting allows one user to send packets to several users for
conferencing. The M-Bone is overlay on the Internet that will allow one
site to broadcast to many users at once. In addition to being used for
voice conferencing, multicasting can be used to make the Internet a
broadcast service to allow users to hear live radio broadcast or even
see live video of events like Space Shuttle launchings. For more
information about the MBONE, see http://org1000-www.cs.sandia.gov/mbone.html
and http://www.best.com/~prince/techinfo/mbone.html

+++ CAN I TALK TO USERS ACROSS PC/MAC/UNIX PLATFORMS?
Yes. Speak Freely offers full compatibility between Windows and Unix
users. CU-SeeMe offers full compatibility between Mac and PC users.

+++ CAN I TALK TO USERS OF OTHER PHONE SOFTWARE?
Maybe. To talk to others using different software you need to have the
same type of connection scheme and the same type of compression. There
are two standards emerging for establishing connections that are
emerging, VAT and RTP, which are compatible with each other. Since VAT
was the first working voice conferencing program, many other
applications have mimicked its method of establishing a call. Programs
using RTP will use the same connection procedure but will have added
capabilities to control call quality.

Those applications that conform to the RTP/VAT standard include Maven,
Netphone, Vat, Nevot and soon Speak Freely. GSM seems to be emerging as
the compression standard and is supported by Maven, Netphone, Speak
Freely, Internet Global Phone and Nevot.  There are also slight
variations between the compression algorithms that might still cause
compatibility problems.

If you are using a commercial product with a proprietary compression
system, then you are out of luck because you will not be able to talk
with people using any other type of software.

*** WHAT SOFTWARE IS AVAILABLE?
+++ For the Mac
>>> Maven
Maven was the first Internet audioconferencing tool for Macintosh. Maven
is free software, but it is a bandwidth hog. Maven requires a minimum of
13KBPS. The program can talk to other Macs running Maven, as well as the
UNIX vat program.

Platform: Macintosh, 16BPS of bandwidth
Encoding/compression: vat or Maven-proprietary
Features:  Full/Half Duplex
Negatives:  Uses more than 14.4k of bandwidth
Mailing list: send e-mail:
     To: [e-mail]
     Body: subscribe maven your name
Software: ftp://sunsite.unc.edu/pub/packages/infosystems/maven
          ftp://ftp.univie.ac.at/systems/mac/info-mac/comm/tcp
Cost: free

>>> NetPhone
NetPhone, like Maven, it gives an Internet-connected Macintosh the
ability to do audioconferencing. But NetPhone works over slower
connections, even with a 14.4KBPS modem. At a sampling rate of 10,000
samples per second, the sound quality isn't wonderful, but the voice of
my NetPhone compatriots are certainly understandable. There's a free
demo version of NetPhone available that limits calls to 90 seconds.

Platform: Mac LC or faster, 14.4KBPS modem
Encoding/compression: vat, CVSD, GSM
Features: User Directory, Full/Half duplex, Good Compatibility/VAT
compatible, WWW Compatible
Negatives: sometimes has poor sound quality, demo only last for 90
seconds
E-mail: [e-mail]
Web page: http://www.emagic.com/
Software: http://www.emagic.com/
Mailing list: send e-mail:
     To: [e-mail]
     Body: subscribe
Cost: $75 per copy, or $125 for two copies. Free demo.

>>> PGPfone
This product comes from the makers of the PGP encryption scheme. It is
currently only available in beta format for Macs, but a Windows 95
version will be available soon. The encryption scheme used in the
application is banned for US export, and because of current lawsuits
against the makers of PGP, users outside the US must use a different
version. The current version only supports full duplex.

Platform: Macintosh
Encoding: PGP
Features: Good encryption
Negatives: Only beta version, Only full duplex sound supported
Web page: http://web.mit.edu/network/pgpfone/
Cost: Free

>>> CU-SeeMe for Mac
See description in Windows section.

+++ For Windows
>>> Speak Freely
Speak Freely is written John Walker, the founder of Autodesk.  It is
free and one of the best applications available. It offers many advanced
features such as voice mail, multicasting, encryption, and usually
offers excellent sound quality. Its GSM compression routine requires a
high-end 486 or Pentium processor. Will work for 14.4 modems with GSM,
but sound quality is degraded. Current version is not compatible with
other software except for Speak Freely for Unix. Complete source code is
available.

Version 6.0 will be compatible with the VAT/RTP standard and will
include DVI4 and L16 compression and will include a user directory
accessible from within the application and on WWW.

Platform: Windows 3.1, 386 Enhanced Mode, Winsock, 14.4KBPS modem
Encoding/compression GSM, ADPCM, PCM, PGP, DES, IDEA
Features: Voice Mail, good variety in compression/encoding, excellent
sound quality, full/half duplex, multicasting for conferences, WWW
compatible
Negatives: sound quality is marginal over 14.4k modems
E-mail: [e-mail]
Web Page: http://www.fourmilab.ch/netfone/windows/speak_freely.html
Software: Windows: http://www.fourmilab.ch/netfone/windows/speakfb.zip
          Unix: http://www.fourmilab.ch/netfone/unix/speak_freely-5.3.tar.gz
Source Code: http://www.fourmilab.ch/netfone/windows/speakfs.zip
Voice Chat Room: http://rpcp.mit.edu/~asears/voice.html
Cost: Free

>>> CU-SeeMe for Windows and Mac
CU-SeeMe is a project of  Cornell University for audio and video
conferencing over the Internet.  Sound quality is good, but your might
have problems with a 14.4k connection.  Viewing images is impossible at
14.4k and is slow and 28.8k, but audio conferencing will work without
images. Users can transmit images using a camera that can be purchased
for as little as $99, but a camera is not needed.

One main advantages of CU-SeeMe for audio conferencing is that users can
either connect directly to each other or they can enter a multi-person
conference at a reflector. In addition, CU-SeeMe probably offers the
best compatibility with other applications.

Features:  Good conferencing capabilities, and allows for video
conferencing, good sound quality, compatible across Windows/Mac, WWW
compatible
Negatives: Need at least a 28.8k connection
Web Page: http://cu-seeme.cornell.edu/
Mailing list: send e-mail:
     To: [e-mail]
     Body: Subscribe CU-SEEME-L Firstname Lastname
Software: Windows: ftp://cu-seeme.cornell.edu/pub/CU-SeeMe/PC.CU-SeeMeW0.70b1/cuseeme.zip
          Mac: ftp://CU-SeeMe.cornell.edu/pub/CU-SeeMe/Mac.CU-SeeMe0.80b2/CU-SeeMe.68k0.80b2.bin
          PowerMac: ftp://CU-SeeMe.cornell.edu/pub/CU-SeeMe/Mac.CU-SeeMe0.80b2/CU-SeeMe.ppc.0.80b2.bin

>>> Internet Phone
Internet Phone runs on top of Internet Relay Chat, providing you with a
list of on-line users and topics of conversation, making it easy to find
new people to chat with. Quickly becoming one of the most used
applications because the software makes it easy to find others to talk
to. The main disadvantage is that that the software is one of the few
application that only offer proprietary compression scheme, which makes
it impossible for it to be compatible with other applications. The test
version allows for one minute of conversation before it times out.

Platform: Windows 3.1, 33 MHz 486 or faster, Winsock 1.1, 14.4KBPS modem
Encoding/compression: Internet Phone proprietary
Features: Excellent user directory, full/half duplex, low bandwidth
demands
Negatives: Demo limited to one minute, not compatible with any other
software, cannot make connections without using IRC
E-mail: [e-mail]
Web page: http://www.vocaltec.com/
User directory: http://www.pulver.com/
Software: ftp://ftp.vocaltec.com:/pub (one minute demo)
Mailing list: send e-mail:
     To: [e-mail]
     Body: subscribe iphone
Cost: $99

>>> DigiPhone
This is application just recently was made available. Because they do
not offer a test version, little is known about how well it works.
DigiPhone has had major hype but is hard to find - the company seems to
have a much better marketing department than distribution department.
While it seems that they have invested heavily in advertising, they
offer no WWW distribution of their product.

Another version, DigiPhone Deluxe, includes a Web browser, E-mail,
telnet, FTP, voice messaging and caller ID.

Features: Good integration with other Internet applications
Negatives: Not available on the Internet, not compatible with other
software
E-mail: [e-mail]
Web page: http://www.planeteers.com/
Software: Not Available on the Internet
Compression: Proprietary
Cost: $89.95. $149.95 for DigiPhone Deluxe

>>> Internet Global Phone
Internet Global Phone is not a clean, ready-to-use application. In fact,
it is very much a work in progress. Internet Global Phone is a
"technology demonstration project" providing a code platform for two way
real-time voice exchange over the Internet. The details of the project
are documented in an article in Dr. Dobb's Journal in December 1994. If
you like hacking in Microsoft Visual C++, you too can hack on Internet
Global Phone. IGP currently lacks a real user interface.

Platform: Windows 3.1, 20 MHz 386 or faster, 14.4KBPS modem
Encoding/compression: GSM
E-mail: [e-mail] (Sing Li)
Software: ftp://ftp.cica.indiana.edu:/win3/demos/IGP*
Source code: ftp://ftp.cs.tu-berlin.de:/pub/local/kbs/tubmik/gsm/ddj
Cost: free

>>> WebPhone (vaporware)
WebPhone is an unreleased product of Quarterdeck. Their aim will be to
integrate WebPhone with their Web browser.

Web page: http://www.qdeck.com/qdeck/press/webphone.html
Cost: Less than $50

>>> Internet Voice Chat (defunct)
Internet Voice chat is no longer available.

+++ For UNIX
>>> Speak Freely for Unix
See information above in the Windows section

>>> CyberPhone
New addition to the FAQ. Very little is known about CyberPhone at this
time.

Platforms: Sun running SunOS or Solaris, 386/486/586 running Linux
1.2.8+ and X Windows
Web site: http://magenta.com/cyberphone/
Software: ftp://magenta.com/pub/cyberphone
Email: [e-mail]
Mailing list: send email:
   To: [e-mail]
   Body: subscribe cyberlist
Cost: $20. Free demo available.

>>> NEVOT
NEVOT (Network Voice Terminal) provides voice communications using
unicast, simulated multicast or IP multicast, using the vat or RTP
protocols. Requires a high-end workstation.

Encoding/compression: vat, RTP, GSM, LPC
Platforms: SunOs 4.1, Solaris 2, Irix, HP/UX
Features: RTP/VAT compatible, good controls, WWW compatible
Web site: http://www.fokus.gmd.de/step/employees/hgs/nevot/nevot.html
Software: ftp://gaia.cs.umass.edu/pub/hgschulz/nevot
          ftp://ftp.fokus.gmd.de/pub/minos/nevot
Cost: free

>>> Vat
Vat was the first audio conferencing tool for the Internet. Requires a
high-end UNIX machine. The VAT standard for setting up a call is quickly
becoming the dominant standard along with RTP, which will allow users of
different applications to communicate.

Encoding/compression: vat
Platforms: Sun Sparcstation, Silicon Graphics and DECstation 5000
Software: ftp://cs.ucl.ac.uk/mice/videoconference/vat/
Cost: free

>>> MTALK
MTALK is an "very alpha" experimental voice-talk system for LINUX. It
uses low bandwidth (approx. 1 KBPS) and claims to work even on computers
with very low bandwidth connections. Requires a LINUX workstation with a
Soundblaster compatible sound-card.

Encoding/compression: unknown
Platforms: Linux
E-mail: [e-mail]
Software: ftp://sunsite.unc.edu/pub/Linux/apps/sound/talk/
Source code: ftp://sunsite.unc.edu/pub/Linux/apps/sound/talk/
Cost: free

>>> ZTALK
Simple, "Extremely alpha" voice software for Linux. Includes a voicemail
feature.

Encoding/compression: GSM
Platforms: Linux
E-mail: [e-mail]
Source code: ftp://sunsite.unc.edu/pub/Linux/apps/sound/talk/
Cost: free

*** WHAT HARDWARE IS AVAILABLE?
>>> Jarba Earphone
Combo microphone and earphone for Mac or PC: http://www.jabra.com

>>> Sound Advantage
Microphone for Macintosh: http://www.emagic.com/soundadv/

*** LEGAL STUFF
This document is copyright 1995 by Kevin M. Savetz and Andrew Sears. All
rights reserved.

Permission for the following types of distribution is hereby granted,
provided that this file is distributed intact, including the above
copyright notice:
     - non-commercial distribution
     - posting to Internet archives, BBSs and online services
     - distribution by teachers, librarians and Internet trainers
     - inclusion on software/FAQ/Internet-oriented CD-ROMs

Permission for commercial distribution may be obtained from the editor.
SHARE THIS INFORMATION FREELY AND IN GOOD FAITH. DO NOT DISTRIBUTE
MODIFIED VERSIONS OF THIS DOCUMENT.

This document is new and in transition. If you notice that something
important is missing, or information herein needs updating, please
contact the editor.

The editor and contributors have developed this FAQ as a service to the
Internet community. We hope you find it useful. This FAQ is purely a
volunteer effort. Although every effort has been made to insure that
answers are as accurate as possible, no guarantee is implied or
intended. While the editor tries to keep this document current, remember
that the Internet and its services are constantly changing, so don't be
surprised if you happen across statements which are obsolete. If you do,
please send corrections to the editor. Corrections, questions, and
comments should be sent to Kevin Savetz at [e-mail] and
Andrew Sears at [e-mail] -- please indicate what version of this
document to which you are referring.

*** WHERE TO FIND THIS DOCUMENT
Oh boy! This FAQ has been rated among the top 5% of all sites on the
Internet by Point Survey.

This file is posted on the 5th and 19th of each month to Usenet
newsgroups alt.internet.services, alt.bbs.internet,
alt.culture.internet, alt.winsock.voice, alt.winsock.ivc,
comp.sys.mac.comm, comp.os.ms-windows.apps.comm, alt.answers,
comp.answers, and news.answers

You can find it on the World Wide Web:
http://www.northcoast.com/~savetz/voice-faq.html
http://rpcp.mit.edu/~sears/voice-faq.html

You can receive each new edition of this document automatically via
electronic mail, if you are so inclined. This is a low-volume list, with
updates every few weeks. To subscribe, send e-mail:
     To: [e-mail]
     Subject: subscribe voice-faq
     Body: <ignored>

You can also receive it once via electronic mail (without subscribing to
automatic updates).
     To: [e-mail]
     Subject: archive
     Body: send voice-faq

You can also receive it via anonymous FTP, in:
ftp://rtfm.mit.edu:/pub/usenet/alt.internet.services/

###end of document###