The Internet Stream Protocol (ST) is a family of experimental protocols first defined in Internet Experiment Note IEN-119 in 1979, and later substantially revised in RFC 1190 (ST-II) and RFC 1819 (ST2+).
The protocol uses the version number 5 in the version field of the
Internet Protocol
The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.
...
header, but was never known as IPv5. The successor to
IPv4 was thus named
IPv6 to eliminate any possible confusion about the actual protocol in use.
History
The Internet Stream Protocol family was never introduced for public use, but many of the concepts available in ST are similar to later
Asynchronous Transfer Mode
Asynchronous Transfer Mode (ATM) is a telecommunications standard defined by American National Standards Institute (ANSI) and ITU-T (formerly CCITT) for digital transmission of multiple types of traffic. ATM was developed to meet the needs of ...
protocols and can be found in
Multiprotocol Label Switching
Multiprotocol Label Switching (MPLS) is a routing technique in telecommunications networks that directs data from one node to the next based on labels rather than network addresses. Whereas network addresses identify endpoints the labels identif ...
(MPLS). They also presaged
voice over IP.
ST arose as the transport protocol of the
Network Voice Protocol, a pioneering computer network protocol for transporting human speech over packetized communications networks, first implemented in December 1973 by Internet researcher
Danny Cohen of the
Information Sciences Institute (ISI) as part of
ARPA's Network Secure Communications (NSC) project.
First specified in 1979, ST was envisioned as a connection-oriented complement to
IPv4, operating on the same level, but using a different header format from that used for IP datagrams. According to IEN-119, its concepts were formulated by Danny Cohen, Estil Hoversten, and James W. Forgie. The protocol was notable for introducing the concepts of
packetized voice (as used by voice over IP), a
talkspurt (a continuous segment of speech between silent intervals), and specified delay and drop-rate requirements for packet services. It was implemented in the
Voice Funnel.
Its second version, known variously as ST-II or ST2, was drafted by Claudio Topolcic and others in 1987 and specified in 1990. It was implemented in the
Terrestrial Wideband Network and its successor, the
Defense Simulation Internet, where it was used extensively for distributed simulations and videoconferencing. This version later formed the core technology for transporting voice calls and other realtime streams within Canada's
Iris Digital Communications System.
The final version of ST2, which was also known as ST2+, was drafted by the IETF ST2 Working group and published in 1995 as RFC 1819.
ST2 distinguishes its own packets with an
Internet Protocol
The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.
...
version number 5, although it was never known as IPv5.
ST uses the same IP address structure and the same
link layer protocol number (ethertype 0x800) as IP.
In
datagram mode, ST packets could be encapsulated with IP headers using
protocol number 5.
See also
*
IPv6 – Internet Protocol Version 6
References
{{reflist , 64em
Bibliography
* Cohen, D., "Specifications for the Network Voice Protocol", Technical Report ISI/RR-75-39, USC/Information Sciences Institute, Marina del Rey, CA (Mar 1976).
* Cohen, D., "A Network Voice Protocol NVP-II" and "Sample NVP/ST Scenarios" (unpublished memorandums), USC/Information Sciences Institute, Marina del Rey, CA (Apr 1981).
*Topolcic, C., Park, P., Draft of "Proposed Changes to the Experimental Internet Stream Protocol (ST)", BBN Laboratories, Cambridge, MA (Apr 1987).
Internet Protocol
Audio network protocols