Internetworking with TCP/IP- P76: TCP/IP has accommodated change well. The basic technology has survived nearly two decades of exponential growth and the associated increases in traffic. The protocols have worked over new high-speed network technologies, and the design has handled applications that could not be imagined in the original design. Of course, the entire protocol suite has not remained static. New protocols have been deployed, and new techniques have been developed to adapt existing protocols to new network technologies | TCP IP Internet Terms In Alphabetical Order 709 RTO Round trip Time-Out The delay used before retransmission. TCP computes RTO as a function of the current round trip time and variance. RTP Real-time Transport Protocol The primary protocol used to transfer real-time data such as voice and video over IP. RTT Round Trip Time A measure of delay between two hosts. The round trip time consists of the total time taken for a single packet or datagram to leave one machine reach the other and return. In most packet switching networks delays vary as a result of congestion. Thus a measure of round trip time is an average which can have high standard deviation. SA Security Association Used with IPsec to denote a binding between a set of security parameters and an identifier carried in a datagram header. A host chooses SA bindings they are not globally standardized. See SPI. SACK Selective Acknowledgement An acknowledgement mechanism used with sliding window protocols that allows the receiver to acknowledge packets received out of order but within the current sliding window. Also called extended acknowledgement. Compare to the cumulative acknowledgement scheme used by TCP. SAR Segmentation And Reassembly The process of dividing a message into cells sending them across an ATM network and reforming the original message. AAL5 performs SAR when sending IP across an ATM network. segment The unit of transfer sent from TCP on one machine to TCP on another. Each segment contains part of a stream of bytes being sent between the machines as well as additional fields that identify the current position in the stream and a checksum to ensure validity of received data. selective acknowledgement See SACK. self clocking Characteristic of any system that operates periodically without requiring an external clock . uses the arrival of a packet to trigger an action . self-healing Characteristic of a mechanism that overcomes failure automatically. A dual FDDI ring is self-healing because it can
