Chapter 7 - Transport layer protocols. Chapter 7 provides knowledge of TCP, UDP, SPX, and NCP. This chapter includes contents: Connection-oriented protocol; provides packet acknowledgment and flow control, much like TCP; used for NetWare file sharing traffic, among many other functions | Chapter Overview TCP and UDP SPX and NCP TCP Characteristics TCP is the acronym for Transmission Control Protocol. TCP is Connection oriented Reliable It is used to carry large amounts of data. It provides services that Internet Protocol (IP) lacks. TCP is defined in Request for Comments (RFC) 793. TCP Functions Guaranteed delivery Packet acknowledgment Flow control Error detection Error correction Segmentation TCP splits application layer messages into datagram-sized segments and encapsulates each segment with its own header. The collection of segments is called a sequence. The destination system reassembles the segments into the original sequence. The segmentation process is completely separate from the network layer fragmentation process. The TCP Message Format Port Numbers and Sockets A port number refers to a specific application or process running on a computer. A socket is a combination of a port number and an IP address. The Internet Assigned Numbers . | Chapter Overview TCP and UDP SPX and NCP TCP Characteristics TCP is the acronym for Transmission Control Protocol. TCP is Connection oriented Reliable It is used to carry large amounts of data. It provides services that Internet Protocol (IP) lacks. TCP is defined in Request for Comments (RFC) 793. TCP Functions Guaranteed delivery Packet acknowledgment Flow control Error detection Error correction Segmentation TCP splits application layer messages into datagram-sized segments and encapsulates each segment with its own header. The collection of segments is called a sequence. The destination system reassembles the segments into the original sequence. The segmentation process is completely separate from the network layer fragmentation process. The TCP Message Format Port Numbers and Sockets A port number refers to a specific application or process running on a computer. A socket is a combination of a port number and an IP address. The Internet Assigned Numbers Authority (IANA) assigns well-known port numbers to common Internet applications. The most commonly used port numbers are listed in the Services file on computers running TCP/IP. Clients choose ephemeral port numbers at random. Control Bits Control Bit Function URG Indicates that the segment contains urgent data ACK Indicates that the message acknowledges a previously transmitted segment PSH Indicates that the receiving system should forward the message immediately rather than wait for the rest of the sequence RST Resets the TCP connection and discards the segments received so far SYN Synchronizes the Sequence Number values for both systems FIN Terminates a TCP connection Three-Way Handshake Functions Verify that both computers are operating and ready to receive data Exchange initial sequence numbers (ISNs) Exchange maximum segment sizes (MSSs) Exchange port numbers Three-Way Handshake Messages Transmitting Data Information needed to transmit data: Port number Sequence number
