Practical TCP/IP and Ethernet Networking- P4: The transmitter encodes the information into a suitable form to be transmitted over the communications channel. The communications channel moves this signal as electromagnetic energy from the source to one or more destination receivers. The channel may convert this energy from one form to another, such as electrical to optical signals, whilst maintaining the integrity of the information so the recipient can understand the message sent by the transmitter | Contents xv Network utilization low but errors high High number of packets but low data transfers Troubleshooting with TCP IP utilities Example of use of a few of the utilities together Unreliable connections Network congestion 251 251 251 253 253 253 18 SatellitesandTCP IP__255 Introduction 255 Overview of satellite communications 255 Advantages of satellite networks 258 Applications of satellite systems 259 Remote control and login 259 Videoconferencing 259 Electronicmail 260 Informationretrieval 260 Bulk information broadcasting 260 Interactivegaming 260 Review of TCP IP 261 Internet protocol or IP protocol 261 Transmission control protocol or TCP 262 Weaknesses of TCP IP in satellite usage 265 Windowsizetoosmall 265 Bandwidthadaptation 265 Selectiveacknowledgment 266 Slowstart 266 TCPfortransactions 266 Methods of optimizing TCP IP over satellite channels 266 Appendix A Glossary 270 Appendix B Port number allocation 290 Index 293 Preface One of the great protocols that has been inherited from the Internet is TCP IP and this is being used as the open standard today for all network and communications systems. The reasons for this popularity are not hard to find. TCP IP and Ethernet are truly open standards available to competing manufacturers and providing the user with a common standard for a variety of products from different vendors. In addition the cost of TCP IP and Ethernet is low. Initially TCP IP was used extensively in military applications and the purely commercial world such as banking finance and general business. But of great interest has been the strong movement to universal usage by the hitherto disinterested industrial and manufacturing spheres of activity who have traditionally used their own proprietary protocols and standards. These proprietary .
