ERCIM News No.25 - April 1996 - INRIA
Integration of Real-Time Multimedia into the Web
by Philipp Hoschka
It is possible today to use the Internet in general and the Web in particular
for transmitting audio and video streams. This is not new to the research
community, where broadcasting of conferences or space shuttle launches live
over the Internet-Mbone have become a regular event. However, the business
world is just discovering this new and exciting possibility, and virtually
no week passes without a new release of products offering "a free telephone
service over the Internet".
Transmission of real-time data is not trivial given the best-effort service
of today's Internet. Packets may be delayed or lost arbitrarily. To overcome
some of these issues without any changes to the current Internet, the Real
Time Protocol (RTP) has been developed and standardised within the IETF.
Two ERCIM institutes (GMD Fokus, Berlin and INRIA Rodeo, Sophia-Antipolis)
have made significant contributions to this standard. One of the missions
of the WWW consortium is to spread information about RTP in the commercial
world, where most products today use proprietary and thus incompatible protocols.
This endangers interoperability, and thus the very foundation of the Web.
The recent adoption of RTP by Netscape in its LiveMedia proposal is a step
in the right direction.
A further mission of the WWW consortium is extending today's Web protocols
in a way that facilitates the integration of real-time resources into the
Web. Due to the origins of the Web as a static, hypertext-based file transfer
service, integration of real-time applications today is still rather superficial.
Full integration requires extensions to the standards that make up the web
today, ie the http protocol, the URL addressing scheme and the html document
description language. These standard extensions will enable the use of the
Web for audio- and video-on-demand, as an interface to Internet telephones
and for voice-annotated slide shows.
Hoschka - INRIA
Tel: +33 93 65 79 84
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