Chapter 16 - TCP: Software For Reliable Communication

1
Chapter 16 - TCP Software For Reliable
Communication

• Introduction
• A Packet Switching System Can Be Overrun (merging
  highways)
• TCP Helps IP Guarantee Delivery
• Although IP software allows a computer to send
  and receive datagrams, IP does not handle all the
  problems that can arise. A computer using the
  Internet also needs TCP software to provide
  error-free communication.
• TCP Provides A Connection Between Computer
  Programs (uses port numbers to identify session)
• TCP software makes it possible for two computer
  programs to communicate across the Internet in a
  manner similar to the way humans use a telephone.
  Once the programs establish a connection, they
  can exchange arbitrary amounts of data and then
  terminate communication.

2
Chapter 16 - TCP Software For Reliable
Communication

• The Magic Of Recovering Lost Datagrams
• TTL time to live
• TCP Retransmission Is Automatic
• TCP and IP Work Together
• A computer connected to the Internet needs both
  TCP and IP software. IP provides a way to
  transfer a packet from its source to its
  destination, but does not handle problems like
  datagram loss or delivery out of order. TCP
  handles the problems that IP does not. Together,
  they provide a reliable way to send data across
  the Internet.

3
Chapter 16 - TCP Software For Reliable
Communication

• TCP is connection-oriented vs. UDP (User Datagram
  Protocol) which is connectionless TCP used by
  most applications (e.g. e-mail, web, etc.) that
  require that data must get there, UDP uses by
  applications that don't care, e.g. games
• Terms
• Transmission Control Protocol (TCP)
• User Datagram Protocol(UDP)
• port numbers
• acknowledgement
• retransmission
• congestion