Skills: none Concepts: host, TCP/IP communication software, TCP/IP layers, TCP/IP functions, TCP/IP protocols This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License. TCP/IP communication software
Where does this topic fit? Internet concepts – Applications – Technology (communication) – Implications Internet skills – Application development – Content creation – User skills
TCP/IP from the outside Application Program, for example, a Web client Application Program, for Example, a Web server A TCP/IP network
LAN Internet Router A closer look
TCP/IP the very big picture Layer Function Application programs Do useful work like Web browsing, , and file transfer TCP/IP communication software Handle communication between the client and server
TCP/IP is a standard
LayerFunction Application Do useful work like Web browsing, , and file transfer Transport Handle communication between the client and server Internet Data link Physical TCP/IP a closer look
Function of each layer LayerFunction ApplicationDo useful work like Web browsing, , and file transfer TransportTransport data between application programs running on two hosts InternetRoute packets between networks (inter network) Data linkSend data within the local area network PhysicalSpecify hardware characteristics and ways to differentiate between ones and zeros
Protocols at each layer LayerProtocol ApplicationMany depending upon the application TransportTCP or UDP InternetIP Data linkEthernet and WiFi most common PhysicalMany wireless, copper wire, optical fiber, etc.
Application (do useful work) Transport (app to app communication) Internet (net to net communication) Physical (LAN, WAN links) Data link (LAN communication) TCP/IP hierarchy -- responsibilities
Application (many) Transport (UDP, TCP) Internet (IP) Physical (LAN, WAN links) Data link (Ethernet, WiFi) TCP/IP hierarchy -- protocols
Application Transport Internet Data link Network Access or Network Interface Physical Alternate terminology
Summary LayerFunction ApplicationDo useful work like Web browsing, , and file transfer TransportTransport data between application programs running on two hosts InternetRoute packets between networks (inter network) Data linkSend data within the local area network PhysicalSpecify hardware characteristics and ways to differentiate between ones and zeros
Self-study questions 1.We have a local area network at school that connects to the Internet. Do you have a LAN at home? How many computers connect to it? How does it connect to the Internet? 2.When you connect to the Internet using a mobile device like a phone or a tablet, are you connecting to a network that is connected to the Internet? Explain. 3.We saw that there were two commonly protocols at the transport layer – TCP for reliable communication and UDP for fast, but unreliable communication. Which would an application programmer use for a file-transfer program? Which would an application programmer use for a streaming video program? Explain your answers.
Application Physical Do you recall the names of the TCP/IP protocol layers?
Do you recall the functions of the software at each layer? Application: Transport: Internet: Data link: Physical:
Do you recall the protocol(s) used at each layer? Application: Transport: Internet: Data link: Physical:
Resources Terminology used by selected authors: number_of_layers_in_the_literature