Packet Switching:Tomorrow's Communications Today
暂无分享,去创建一个
One What is a Packet?.- 1. To Switch or Not to Switch.- What Is Packet Switching?.- Why Use a Switched Network?.- Summary.- Suggested Readings.- 2. Packet Switching in a Telephone World.- Switching through the Telephone.- Transparent and Transactional Switching.- Approaches to Switching Compared.- Data Communications versus Voice Communications.- Data Call Statistics.- The Why and Where of Packet Switching.- Summary.- Suggested Readings.- 3. Circuit Switching/Message Switching/Packet Switching-A Quick Comparison.- Circuit Switching.- Message Switching.- Packet Switching.- Circuit Switching of Data-Advantages and Disadvantages.- Message Switching of Data-Advantages and Disadvantages.- Packet Switching of Data-Advantages and Disadvantages.- Summary 38 Suggested Readings.- 4. Getting Started with Network Basics.- The Network Environment.- The Example of the Public Telephone Network.- The Network User and the Network Supplier-Two Sides of the Coin.- Design Considerations.- Summary.- Suggested Readings.- 5. What Is an Erlang? An Introduction to Telecommunications Traffic Engineering.- Statistical Behavior of Network Users.- Traffic and User Satisfaction.- Blocking, Lines, and Erlangs.- Networks with Storage and Delay Instead of Blocking.- Capacity of Networks-Some Examples.- Summary.- Suggested Readings.- 6. Quantitative Tradeoffs-Packet, Circuit, and Message Switching.- Packet Switching-Operational Detail and Possible Faults.- Packet Switching-Overhead Structure Fundamentals.- Delay Comparison-Ideal Case.- Data Traffic Impact on Processor Loading.- Overhead in Circuit Switching and Packet Switching.- A Nationwide Data Network.- Summary.- Suggested Readings.- Two Operational Protocols-Packet Switching In Networks.- 7. Protocol Structures in Packet Switched Networks.- Types of Network Protocols.- The International Standards Organization (ISO) Protocol Hierarchy.- The ARPANET Approach to Protocols.- Virtual Circuit.- Datagrams.- Two Classes of Terminals.- Summary.- Suggested Readings.- 8. The User-Network Interface-The X.25 Standard.- The Packet-Switched Network User's Perspective.- The X.25 Protocol-Level 3 Features and Facilities.- User Actions under the X.25 Protocol.- Summary.- Suggested Readings.- 9. Control and Monitoring in a Network-Some Considerations.- The Role of Control.- Network Control Centers for Packet Networks.- Summary.- Suggested Readings.- Three Packet Networks in the Real World-Topology, Routing, Robustness, and Some Lucky Guesses.- 10. Topological Principles-Some Tricks to Make Packet Switching Work Better.- Alternative Topological Structures.- The General Topological Design Problem.- Desirable Topological Features for Packet Switching.- Summary.- Suggested Readings.- 11. Network Design Case Example-Even a Bad Guess Is Better Than None.- The Network Design Requirements.- The Impact of Topology and Data Rate on Network Resources.- Detailed Requirements and Bad Guesses.- Summary.- Suggested Readings.- 12. Routing in Packet Networks.- Alternative Routing Methods.- Advantages and Disadvantages of Routing Methods.- Approaches to Adaptive Directory Routing.- Summary.- Suggested Readings.- Four Packet Switching Without Packet Switches.- 13. Resource Sharing and Multiple Access Techniques.- The General Problem of Communications Resource Sharing.- The Satellite-Based ALOHA Technique.- The Network Aspect of the Packet Broadcast Channel.- Capacity and Delay of the ALOHA Channel.- ALOHA Channel Delay Characteristics.- Summary.- Suggested Readings.- 14. Improvements on the Basic ALOHA Channel-Slots and Reservations.- Increasing the Capacity of the Packet Broadcast Channel.- The Slotted ALOHA Channel.- Slotted ALOHA Channel with Capture.- Packet Broadcast Channels with Capacity Reservation.- Highlight Comparison of Multiple Access Techniques.- Summary.- Suggested Readings.- 15. Terrestrial Packet Radio Systems.- Terrestrial Repeaters and Local Networks.- Carrier Sense Multiple Access-Listen Before You Send.- Summary.- Suggested Readings.- 16. Combination of Satellite and Terrestrial Connectivity-The General Optimization Problem.- Serving Users without Dedicated Earth Stations-The General Problem.- Deriving the Optimum Value of the Number of Earth Stations.- Applications and Examples of the Random Network Analysis.- Summary.- Suggested Readings.- Five Data Networks, Packet Switching, and the Common Carriers.- 17. The Carrier Marketplace.- Common Carrier Services and Facilities.- Common Carriers in the United States.- Summary.- Suggested Readings.- 18. Value-Added Networks (VANs) and Packet Switching.- Public Networks and the Role of VANs.- The Telenet Packet Switched Network.- The Tymnet Nationwide Data Network.- Worldwide Packet Switching Services.- Summary.- Suggested Readings.- 19. A Tariff for Every Occasion.- A Sample of Common Carrier Communications Tariffs.- A Current and Future Tariff Cost Model.- Summary.- Suggested Readings.- 20. Some New Common Carrier Prospects.- Some Proposed New Telecommunications Services.- AT&T's Advanced Communications Service (ACS).- The Nationwide Network of Satellite Business Systems (SBS).- The Xerox Telecommunications Network (XTEN).- ACS, SBS, and STEN Compared.- Summary.- Suggested Readings.- Six Integrated Networks and the Future of Packet Switching.- 21. Hybrid Techniques: Combining Circuit and Packet Switching.- Classification of Information and Switching Techniques.- Approaches to Integrating Circuit and Packet Switching.- The Master Frame Approach to Integrated Switching.- Summary.- Suggested Readings.- 22. Integrated Services Networks.- Voice Digitization.- General Structure of Integrated Services Packet Switched Networks.- Cost/Performance Analysis.- Summary.- Suggested Readings.- 23. The Outlook for Packet Switching-And What to Do about It.