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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.


 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).


 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

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

Yang [Page 1] 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
 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

Yang [Page 2] RFC 1789 Telephone Service and Servers on Internet April 1995

 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
   (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;

Yang [Page 3] RFC 1789 Telephone Service and Servers on Internet April 1995

   (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.

Yang [Page 4] RFC 1789 Telephone Service and Servers on Internet April 1995

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
 An outline of the proposed open-partnership scheme is listed as
   (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
   (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.

Yang [Page 5] 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,
 [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

Yang [Page 6]

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