Network Working Group C. Yang
Request for Comments: 1789 University of North Texas
Category: Informational April 1995
INETPhone: Telephone Services and Servers on Internet
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.
Yang [Page 1]
RFC 1789 Telephone Service and Servers on Internet April 1995
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.
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.
Yang [Page 2]
RFC 1789 Telephone Service and Servers on Internet April 1995
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.
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.
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;
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 PartnershipVoice 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.
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,
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