Internet Stream Protocol

[5] 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.

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[6][7] and published in 1995 as RFC 1819.

In datagram mode, ST packets could be encapsulated with IP headers using protocol number 5.