Network Working Group                                            C. Yang
Request for Comments: 1789                     University of North Texas
Category: Informational                                       April 1995


        INETPhone: Telephone Services and Servers on Internet

Status of this Memo

  This memo provides information for the Internet community.  It does
  not specify an Internet standard of any kind.  Distribution of this
  memo is unlimited.

IESG Note

  Internet Engineering Steering Group comment from the Transport Area
  Director: Please note well that this memo is an individual product of
  the author.  Work on standards and technology related to this topic
  is additionally taking place in the IETF in the Multiparty MUltimedia
  SessIon Control Working Group (MMUSIC).

Abstract

  INETPhone is a true telephone service through the Internet. It
  integrates the local telephone networks and the Internet using
  INETPhone servers. Thus a long distance call can be split into two
  local calls and an Internet connection, which is transparent to end
  users. Such a phone service through Internet will be a major step
  towards integrated services on Internet. In order to support the
  INETPhone and lay down the ground rules of the service, a scheme of
  "open partnership" is proposed, so that the entire Internet community
  can have the equal opportunity and benefits from the INETPhone
  service.

1. Introduction

  The success of traditional Internet services, such as the electronic
  mail, the file transfer, and the remote machine access, has inspired
  a row of new network applications -- the world-wide information web,
  voice and video conferencing, and network telemarketing are just a
  few to mention.  With the further development in infrastructure and
  the architecture of integrated, multimedia information services
  [1,2,3], certainly the Internet will play a crucial role in shaping
  up the future of so-called information super-highway.

  Among many new applications, the voice communication through Internet
  bears perhaps the most potential impact, since it competes directly
  with the telephone communication, which has become an indispensable



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RFC 1789       Telephone Service and Servers on Internet      April 1995


  part of the modern society.  Recently, many software packages are
  available, either commercially or as public free-ware, which supports
  voice communication on Internet.  Some of these products are targeted
  directly as possible substitution for long distance telephone
  services.  However, so far, all such products only support voice
  communications using a computer that is on the Internet or is
  connected, via a SLIP link, to the Internet [4].

  This RFC presents a true telephone service, called INETPhone, which
  supports voice communication through the Internet.  INETPhone
  integrates the local phone network with the Internet. The phone
  network provides local access of INETPhone service with the existing
  telephone facilities, whereas the Internet delivers the packets of
  voice communication over long distances.  The service of INETPhone is
  illustrated by the following scenario.  Assuming a user at area A
  wants to call another user in area B. The user first makes a local
  call to an INETPhone server in area A. After the connection, the user
  keys in the remote phone number in area B to the server. Then the
  server in area A makes a connection to another INETPhone server in
  area B, and requests the remote server to dial, as a local call, the
  phone number in area B. Therefore, a long distance phone connection
  between users in area A and B is established via two local phone
  connections and one Internet connection between two INETPhone
  servers.

  The INETPhone provides a general service of voice communication on
  Internet compatible to the existing telephone service.  The
  motivation in developing and experimenting the INETPhone service can
  be two-folds: on the one hand, a general telephone service on the
  Internet will be a major step towards integrated services on Internet
  and a great challenge to the future development of Internet
  infrastructure and protocol architecture; on the other hand, the
  entire Internet community can take the advantage from the cheap and
  convenient voice communication of the INETPhone service.

2. Design Philosophy

  The design philosophy of the INETPhone differs from the most of
  current voice communication services on Internet in three basic
  aspects: integrating the existing telephone networks with the
  Internet; using the INETPhone servers to carry out the task of voice
  packet delivery on Internet; and an open-partnership of establishing
  the INETPhone service on Internet.  The discussion of each of these
  aspects is given as follows.

  The conventional telephone service is the most popular and convenient
  means for voice communication across distances. Any serious effort to
  integrate voice communication on the Internet should take the full



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  advantage of this well-established service.  The INETPhone bridges
  the existing telephone network with the Internet, so that the access
  of the INETPhone service will be totally based on the local phone
  services and facilities. This will lead to a much easier access and
  broader user population than the approaches of computer-based access.

  The INETPhone service is based on the client-server model, in which a
  group of INETPhone servers are responsible for accepting/initiating
  local calls and deliverying voice packets across the Internet.  The
  general users (as clients) can easily access the service through a
  conventional phone with a local call. The creation of such INETPhone
  servers eases the burden from general users, and provides services of
  voice communication on the Internet in a more efficient and
  manageable manner.

  Hundreds even thousands of INETPhone servers will be required for the
  wide coverage of INETPhone services on the Internet (to cover all
  areas within US, at least one server needs to be installed in each
  area of phone area code).  Instead of letting few industrials
  monopolize such a service on the Internet, an alternative approach
  based on an open-partnership scheme of INETPhone service is proposed
  (see Section 5), which will give equal opportunity and benefits to
  the entire Internet community.

3. INETPhone Servers

  The central components of the INETPhone service are its servers on
  Internet.  The server acts as a gateway between the telephone network
  and the Internet.  For this purpose, the server will have both
  interfaces to a computer network and the telephone network.
  Currently, there are many commercial telephone interface cards
  available on the market (such as Dialogic's Voice Boards [5]), which
  support various telephone operations of detecting/generating
  telephone signals (ring, DTMF, etc. [6]), receiving/initiating phone
  calls, recording (digitizing and compressing) or playing back audio
  signals, and monitoring the progress of a phone call.

  With the support of necessary hardware interfaces, the function of an
  INETPhone server includes:

    (a) Receive a local call or accept a connection from a remote
        server;

    (b) Identify the PIN of a local call and determine if to proceed
        the call or not;

    (c) Accept a phone number for remote dialing from a local call;




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    (d) Look up the local directory for a remote server of a
        requested call;

    (e) Make a connection to a remote server;

    (f) Make a local phone call upon the request of a remote server;

    (g) Maintain full-duplex, real-time exchanges of voice packets
        via Internet;

    (h) Maintain information exchanges with Directory Servers (see
        Section 4);

    (i) Handle exceptional conditions, such as long delay or drop of
        voice packets;

    (j) Monitor quality of service and keep accounting information.

  The above listed functions represent probably the minimal
  requirements for each INETPhone server. Some further important
  features, such as compression/decompression, security, multicasting,
  and voice mail need also to be considered when a real service of
  INETPhone is launched on the Internet.  Since a general public of the
  Internet community might be involved in this proposed INETPhone
  service, it is probably necessary to set an open standard in the
  building of INETPhone servers (see Section 5).

4. Directory Servers

  The main philosophy behind the INETPhone service is to reduce a long
  distance phone call into two local calls and an Internet connection.
  Therefore, an INETPhone server will always be identified by its IP
  address with its local area code of the phone number (also possibly
  with its sub-regional number).  In order to support a dynamic
  configuration of INETPhone servers on the Internet, a Directory
  Server(s) (DS) will be required to map between IP address and area
  code of INETPhone servers, which in some sense, is similar to the
  functions of a Name Server (such as the BIND [7]).  After an
  INETPhone server is installed on the Internet, it needs to register
  itself with a DS.  The mapping information at DS will be disseminated
  to INETPhone servers for the search of a remote server in response to
  a requested phone call.  Local cache of mapping information may also
  be maintained at INETPhone servers to alleviate communications
  between INETPhone servers and Directory Server(s).  Again, the
  function of a Directory Server for the INETPhone may require another
  open specification.





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5. Open Partnership

  Voice communication and telephone service are important parts for
  providing integrated information services over the Internet.  With
  the current trends of commercialized services over the Internet,
  sooner or later, some kind of telephone services will be launched on
  the Internet by some private companies.  On the other hand, the
  operation of the INETPhone service will depend on the installment of
  enough INETPhone servers over the Internet, which can be achieved
  through a cooperative effort of the entire Internet community.  This
  RFC proposes an open-partnership scheme for the INETPhone service,
  which provides equal opportunity and benefits to the entire Internet
  community.

  An outline of the proposed open-partnership scheme is listed as
  follows:

    (a) Any organization or individual person can join or withdraw
        from this open-partnership on a voluntary base.

    (b) In order to join the partnership (therefore becoming a member
        of the partnership), an organization or a person should at
        least install and maintain an INETPhone server on the
        Internet with the equal capacity of lines for call-in and
        dial-out services.

    (c) Each member of the partnership has the equal right to use the
        INETPhone service through any INETPhone servers on the
        Internet.  All services will bear the same charges based on
        the number of bytes transmitted through the Internet and
        whatever the rate (if any) laid down by the Internet
        authority.

    (d) A not-for-profit consortium will be formed from the
        representatives of all members of the partnership. The main
        task of the consortium is to establish all regulations and
        specifications of the INETPhone service, and to coordinate
        the execution of these rules by all the members.

7. Recommendation

  If there is enough interests in the INETPhone service from the
  Internet community, the IAB may need to consider forming a special
  task force or working group to further look into the matter.







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RFC 1789       Telephone Service and Servers on Internet      April 1995


8. References

  [1] Adie, C., "Network Access to Multimedia Information", RFC 1614,
      Edinburgh University, May 1994.

  [2] Braden, R., Clark, D., and S. Shenker, "Integrated Services in
      the Internet Architecture: an Overview", RFC 1633, ISI, MIT,
      Xerox PARC, June 1994.

  [3] Weider, C., and P. Deutsch, "A Vision of an Integrated Internet
      Information Service", RFC 1727, Bunyip Information Systems,
      December 1994.

  [4] Walters, R., "Computer Telephone Integration", Artech House
      Publishers, Norwood, MA, 1994.

  [5] Dialogic Corporation, "Voice Hardware Reference", Parsippany, NJ,
      1994.

  [6] Noll, M., "Introduction to Telephones and Telephone Systems", 2nd
      Ed., Artech House Publishers, Norwood, MA, 1991.

  [7] Albitz, P., and C. Liu, "DNS and BIND", O'Reilly & Associates,
      Sebastopol, Calif., 1992.

8. Security Considerations

  Security will be an important issue in the INETPhone service.  As a
  general proposal, however, this RFC chooses to leave this topic for
  future discussions.

9. Acknowledgement

  This RFC is based on a currently undergoing project supported by the
  Department of Computer Science, University of North Texas.

10. Author's Address

  Cui-Qing Yang
  Dept. of Computer Science
  University of North Texas
  P.O. Box 13886
  Denton, TX 76203

  Phone: (817) 565-2822
  Fax: (817) 565-2799
  EMail: [email protected]




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