RFC 1819 ST2+ Protocol Specification August 1995 Table of Contents 1 Introduction 6 1.1 What is ST2? 6 1.2 ST2 and IP 8 1.3 Protocol History 8 1.3.1 RFC 1190 ST and ST2+ Major Differences 9 1.4 Supporting Modules for ST2 10 1.4.1 Data Transfer Protocol 11 1.4.2 Setup Protocol 11 1.4.3 Flow Specification 11 1.4.4 Routing Function 12 1.4.5 Local Resource Manager 12 1.5 ST2 Basic Concepts 15 1.5.1 Streams 16 1.5.2 Data Transmission 16 1.5.3 Flow Specification 17 1.6 Outline of This Document 19 2 ST2 User Service Description 19 2.1 Stream Operations and Primitive Functions 19 2.2 State Diagrams 21 2.3 State Transition Tables 25 3 The ST2 Data Transfer Protocol 26 3.1 Data Transfer with ST 26 3.2 ST Protocol Functions 27 3.2.1 Stream Identification 27 3.2.2 Packet Discarding based on Data Priority 27 4 SCMP Functional Description 28 4.1 Types of Streams 29 4.1.1 Stream Building 30 4.1.2 Knowledge of Receivers 30 4.2 Control PDUs 31 4.3 SCMP Reliability 32 4.4 Stream Options 33 4.4.1 No Recovery 33 4.4.2 Join Authorization Level 34 4.4.3 Record Route 34 4.4.4 User Data 35 4.5 Stream Setup 35 4.5.1 Information from the Application 35 4.5.2 Initial Setup at the Origin 35 4.5.2.1 Invoking the Routing Function 36 4.5.2.2 Reserving Resources 36 4.5.3 Sending CONNECT Messages 37 4.5.3.1 Empty Target List 37 Delgrossi & Berger, Editors Experimental