11 TRANSPORT LAYER PROTOCOLS Chapter 6 TCP and UDP SPX and NCP

Chapter 6: TRANSPORT LAYER PROTOCOLS2 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)  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)

Chapter 6: TRANSPORT LAYER PROTOCOLS3 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  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

Chapter 6: TRANSPORT LAYER PROTOCOLS4 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  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

Chapter 6: TRANSPORT LAYER PROTOCOLS5 TCP HEADER AND FIELDS (PAGE 253)

Chapter 6: TRANSPORT LAYER PROTOCOLS6 TCP OPTIONS HEADER AND FIELDS

Chapter 6: TRANSPORT LAYER PROTOCOLS7 EXAMPLE OF A TCP HEADER

Chapter 6: TRANSPORT LAYER PROTOCOLS8 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

Chapter 6: TRANSPORT LAYER PROTOCOLS9 ESTABLISHING A TCP CONNECTION THREE-WAY HANDSHAKE TCP Connection

Chapter 6: TRANSPORT LAYER PROTOCOLS10 EXAMPLE OF A THREE-WAY HANDSHAKE

Chapter 6: TRANSPORT LAYER PROTOCOLS11 TCP CONNECTION TERMINATION

Chapter 6: TRANSPORT LAYER PROTOCOLS12 EXAMPLE OF A TCP CONNECTION TERMINATION

Chapter 6: TRANSPORT LAYER PROTOCOLS13 SEQUENCING AND ACKNOWLEDGMENTS

Chapter 6: TRANSPORT LAYER PROTOCOLS14 POSITIVE ACKNOWLEDGMENT WITH RETRANSMISSION

Chapter 6: TRANSPORT LAYER PROTOCOLS15 FLOW CONTROL

Chapter 6: TRANSPORT LAYER PROTOCOLS16 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  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

Chapter 6: TRANSPORT LAYER PROTOCOLS17 UDP HEADER AND FIELDS (PAGE 266)

Chapter 6: TRANSPORT LAYER PROTOCOLS18 EXAMPLE OF A UDP HEADER

Chapter 6: TRANSPORT LAYER PROTOCOLS19 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: :21) this socket addresses port 21 on the system with address  The Internet Assigned Numbers Authority (IANA) assigns well-known port numbers to common Internet applications.  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: :21) this socket addresses port 21 on the system with address  The Internet Assigned Numbers Authority (IANA) assigns well-known port numbers to common Internet applications.

Chapter 6: TRANSPORT LAYER PROTOCOLS20 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  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

Chapter 6: TRANSPORT LAYER PROTOCOLS21 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  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

Chapter 6: TRANSPORT LAYER PROTOCOLS22 SOCKETS

Chapter 6: TRANSPORT LAYER PROTOCOLS23 NOVELL SPX AND NCP  Novell’s NetWare operating system has two connection-oriented protocols that function at the transport layer:  SPX  NCP  Novell’s NetWare operating system has two connection-oriented protocols that function at the transport layer:  SPX  NCP

Chapter 6: TRANSPORT LAYER PROTOCOLS24 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.  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.

Chapter 6: TRANSPORT LAYER PROTOCOLS25 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.  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.

Chapter 6: TRANSPORT LAYER PROTOCOLS26 SPX HEADER AND FIELDS

Chapter 6: TRANSPORT LAYER PROTOCOLS27 NCP HEADER AND FIELDS

Chapter 6: TRANSPORT LAYER PROTOCOLS28 EXAMPLE OF AN NCP HEADER AND FIELDS

Chapter 6: TRANSPORT LAYER PROTOCOLS29 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.  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.