TRANSPORT LAYER PROTOCOLS

1. Chapter 6 TRANSPORT LAYER PROTOCOLS TCP and UDP SPX and NCP

2. Chapter 6: TRANSPORT LAYER PROTOCOLS TYPES OF TRANSPORT LAYER PROTOCOLS • There are two types of transport layer protocols: • Connection-oriented • Transmission Control Protocol (TCP) • Sequenced Packet Exchange (SPX) • NetWare Core Protocol (NCP) • Connectionless • User Datagram Protocol (UDP)

3. Chapter 6: TRANSPORT LAYER PROTOCOLS TRANSPORT LAYER PROTOCOLS • There are two transport layer protocols in the Transmission Control Protocol/Internet Protocol (TCP/IP) suite: • TCP • UDP • There are two transport layer protocols in the Novell Internetwork Packet Exchange (IPX)/SPX suite: • SPX • NCP

4. Chapter 6: TRANSPORT LAYER PROTOCOLS TRANSMISSION CONTROL PROTOCOL (TCP) • The TCP protocol (described in Request for Comments [RFC] 793) has the following characteristics: • Uses Internet Protocol (IP) ID 06 • Is a reliable, connection-oriented protocol • Provides guaranteed delivery of packets through sequencing and acknowledgments • Provides sliding-window flow control • Performs error detection and correction • Uses ports to identify the communicating process or application

5. Chapter 6: TRANSPORT LAYER PROTOCOLS TCP HEADER AND FIELDS (PAGE 253)

6. Chapter 6: TRANSPORT LAYER PROTOCOLS EXAMPLE OF A TCP HEADER

7. Chapter 6: TRANSPORT LAYER PROTOCOLS ESTABLISHING A TCP CONNECTION THREE-WAY HANDSHAKE • Verify that both computers are operating and ready to receive data • Exchange initial sequence numbers (ISNs) • Exchange maximum segment sizes (MSSs) • Exchange port numbers

8. TCP Connection Chapter 6: TRANSPORT LAYER PROTOCOLS ESTABLISHING A TCP CONNECTION THREE-WAY HANDSHAKE

9. Chapter 6: TRANSPORT LAYER PROTOCOLS TCP CONNECTION TERMINATION

10. Chapter 6: TRANSPORT LAYER PROTOCOLS USER DATAGRAM PROTOCOL (UDP) • UDP (described in RFC 768) has the following characteristics: • Uses IP ID 17 • Provides fast, connectionless delivery of data • Has less overhead than connection-oriented protocols • Uses ports to identify the communicating process or application

11. Chapter 6: TRANSPORT LAYER PROTOCOLS UDP HEADER AND FIELDS (PAGE 266)

12. Chapter 6: TRANSPORT LAYER PROTOCOLS PORTS & 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. (ex: 192.168.2.10:21) this socket addresses port 21 on the system with address 192.168.2.10 • The Internet Assigned Numbers Authority (IANA) assigns well-known port numbers to common Internet applications.

13. Chapter 6: TRANSPORT LAYER PROTOCOLS CLIENT AND WELL-KNOWN PORTS • There are two types of TCP and UDP ports: • Client ports • Variable ports with a value from 1024 through 65,534 • Server (well-known) ports • Commonly used by applications and services • Port values with a value from 1 through 1023

14. Chapter 6: TRANSPORT LAYER PROTOCOLS EXAMPLES OF WELL-KNOWN PORTS (TABLE 6-2 Page 268) • TCP ports • File Transfer Protocol (FTP) 20 and 21 • Telnet 23 • Simple Mail Transfer Protocol (SMTP) 25 • UDP ports • Trivial File Transfer Protocol (TFTP) 69 • Domain Name System (DNS) 53 • Bootstrap Protocol/Dynamic Host Configuration Protocol (BOOTP/DHCP) 67

15. Chapter 6: TRANSPORT LAYER PROTOCOLS SOCKETS

16. Chapter 6: TRANSPORT LAYER PROTOCOLS NOVELL SPX AND NCP • Novell’s NetWare operating system has two connection-oriented protocols that function at the transport layer: • SPX • NCP

17. Chapter 6: TRANSPORT LAYER PROTOCOLS SPX Characteristics • SPX is the acronym for Sequenced Packet Exchange. • SPX is a connection-oriented protocol. • It provides packet acknowledgment and flow control. • It is used infrequently by NetWare. • Messages are carried in Internet Packet Exchange (IPX) datagrams.

18. Chapter 6: TRANSPORT LAYER PROTOCOLS NCP Characteristics • NCP is the acronym for NetWare Core Protocol. • NCP is used for NetWare file sharing traffic. • It is much more frequently used than SPX. • Messages are carried in IPX datagrams. • NCP requires an acknowledgment for each transmitted message.

19. Chapter 6: TRANSPORT LAYER PROTOCOLS SUMMARY • Connection-oriented transport layer protocols like TCP, SPX, and NCP provide guaranteed, reliable delivery of datagrams. • They all exhibit the same characteristics: sequencing, acknowledgments, flow control, error correction and detection, session establishment, and teardown. • Connectionless transport layer protocols like UDP provide fast but unreliable delivery of datagrams. • They do not use sequencing, acknowledgments, flow control, or error correction. • There is no session establishment or teardown.