McGraw-Hill/Irwin © 2008 The McGraw-Hill Companies, All Rights Reserved Business Plug-In B5 Networks and Telecommunications

B5-2 LEARNING OUTCOMES 1.Compare LANs, WANs, and MANs 2.List and describe the four components that differentiate networks 3.Compare the two types of network architectures

B5-3 LEARNING OUTCOMES 4.Explain topology and the different types found in networks 5.Describe TCP/IP along with its primary purpose 6.Identify the different media types found in networks

B5-4 Networks and Telecommunications Telecommunication system - enable the transmission of data over public or private networks Network - a communications, data exchange, and resource-sharing system created by linking two or more computers and establishing standards, or protocols, so that they can work together

B5-5 Network Basics The three types of networks include: –Local Area Network (LAN) –Wide Area Network (WAN) –Metropolitan Area Network (MAN)

B5-6 Network Basics

B5-7 Network Basics Networks are differentiated by the following: –Architecture: peer-to-peer, client/server –Topology: bus, star, ring, hybrid, wireless –Protocols: Ethernet, Transmission Control Protocol/Internet Protocol (TCP/IP) –Media: coaxial, twisted-pair, fiber-optic

B5-8 Architecture There are two primary types of architectures –Client/Server network –Peer-to-peer (P2P) network

B5-9 Client/Server Network Client - a computer that is designed to request information from a server Server - a computer that is dedicated to providing information in response to external requests –Client/server network - model for applications in which the bulk of the back-end processing takes place on a server, while the front-end processing is handled by the clients

B5-10 Client/Server Computing Processing split between client & server machines

B5-11 Client/Server Networks Client/Server network

B5-12 Client/Server Networks Network operating system (NOS) - the operating system that runs a network, steering information between computers and managing security and users Packet-switching - occurs when the sending computer divides a message into a number of efficiently sized units called packets, each of which contains the address of the destination computer Router - an intelligent connecting device that examines each packet of data it receives and then decides which way to send it onward toward its destination

B5-13 Peer-to-peer Network Peer-to-peer (P2P) network - any network without a central file server and in which all computers in the network have access to the public files located on all other workstations

B5-14 Peer-to-Peer (P2P) networking P2P is form of distributed processing that links computers via the Internet or private networks, so that they can share processing, memory and storage. Each computer acts as both its own client and server. Examples : P2P Directory P2P Directory

B5-15 Client/Server Networks Worldwide router growth

B5-16 Trace a route - Visual Route You can see how many routers are between you and any other computer you can name or know the IP address for. Visual Route Try a far away website server such as

B5-17 Topology Network topology - refers to the geometric arrangement of the actual physical organization of the computers and other network devices in a network –Bus topology –Star topology –Ring topology –Hybrid topology –Wireless

B5-18 Topology

B5-19 Videos How a Computer Network Works Bus Topology Star Topology Ring Topology

B5-20 What’s a protocol? a human protocol and a computer network protocol: Hi Got the time? 2:00 TCP/IP connection req TCP/IP connection response Get time

B5-21 Protocols Protocol - a standard that specifies the format of data as well as the rules to be followed during transmission. For two devices on a network to successfully communicate, they must both understand the same protocols. Interoperability - the capability of two or more computer systems to share data and resources, even though they are made by different manufacturers

B5-22 The most popular network protocols used are: –Ethernet –Transmission Control Protocol/Internet Protocol [TCP/IP] Network Protocols

B5-23 Ethernet Ethernet - a physical and data layer technology for LAN networking

B5-24 Ethernet Ethernet is a local area technology with its protocol, with networks traditionally operating within a single building, connecting devices in close proximity.

B5-25 Ethernet Protocol Ethernet protocol standard –Describes how messages are packaged –Determines how messages are processed –Personal computers usually support 10/100/1000 Ethernet transmission rate of 10, 100, or 1000 Mbps (megabits per second)

B5-26 Ethernet Card Any computer as a member of a LAN must have a Ethernet card

B5-27 Ethernet Cable

B5-28 Transmission Control Protocol/Internet Protocol Transmission Control Protocol/Internet Protocol (TCP/IP) - provides the technical foundation for the public Internet as well as for large numbers of private network

B5-29 TCP/IP TCP: provides transport functions, ensuring, among other things, that the amount of data received is the same as the amount transmitted. IP: provides the addressing and routing mechanism that acts as a postmaster

B5-30 TCP/IP Layers TCP/IP has 4 top-to-bottom layers: –Application Layer –Transport Layer –Internet Protocol Layer –Network Layer

B5-31 TCP/IP standard for connectivity Transmission Control Protocol/Internet Protocol Allows any computer to communicate with any other (e.g., a PC and a Mac) Four layers to TCP/IP protocol Specifies: –How sending computer to package data as messages –How messages will be sent over the Internet –How receiving computer will reassemble message for processing

B5-32 TCP/IP applied on

B5-33 Videos TCP/ IP animation Learning Network Protocols

B5-34 Internet Protocol (IP) Address Every node in a network has a unique numeric IP address Form: Four blocks of 3 digit numbers separated by dots Example: (STFX IP address) Each block ranges from 0 to 255. Total number of possible IP addresses: 256 X 256 X 256 X 256 = 4,294,967,296 unique values!

B5-35 Internet Domain Names - Domain names are used because people have difficulty remembering IP numbers Example: is domain name for the IP address:

B5-36 ping How to test if a node is alive: –ping command in DOS –Ping a URL –Ipconfig (DOS) for your own IP address

B5-37 TCP/IP Applications SMTP (Simple Mail Transfer Protocol) –Communication standard for sending and receiving s FTP (File Transfer Protocol) – A communication standard to transfer files over the Internet Telnet (Telnet Protocol) – remote login to a another computer Internet Relay Chat (IRC Protocol) –Communication via chat Usenet (news Protocol) Web ( HTTP Protocol)

B5-38 What Is the Internet? The Internet is a worldwide network of networks that uses the client/server model of computing and based on TCP/IP protocol. Using the Internet, any computer can communicate with any other computer connected to the Internet throughout the world. The Internet has no central management & no owners Major Internet capabilities include , Usenet, chatting and instant messaging, Telnet, FTP, and the World Wide Web.

B5-39 Internet Technology Based on client/server technology Client computers –access services and information available on server computers –Use software to access server computers Web browsers (Netscape, Internet Explorer) software (Eudora, Outlook) Server Computers –They are programs that provide documents to requesting browsers. They are slave programs. –Provide responses to browser requests, either existing documents or dynamically built documents

B5-40 The Browser (client) and The Server The original static model of Web Serving: The HyperText Transfer Protocol (HTTP) enables web pages to be requested and transferred between the browser and server Web Browser Web Server HTTP Request Web Page File System

B5-41 Internet network architecture

B5-42 The Internet connectivity

B5-43 Voice over IP (VoIP) Voice over IP (VoIP) - uses TCP/IP technology to transmit voice calls over long-distance telephone lines VoIP transmits over 10 percent of all phone calls in the United States and this number is growing exponentially.

B5-44 Internet Telephony (VoIP) The basic steps involved in originating an Internet telephone call are conversion of the analog voice signal to digital format and compression/translation of the signal into Internet protocol (IP) packets for transmission over the Internet; the process is reversed at the receiving end

B5-45 Cisco IP Phone

B5-46 Skype VoIP application call forwarding block unwanted calls conference calling Instant msg Video calls

B5-47 Media Network transmission media - refers to the various types of media used to carry the signal between computers –Wire media (guided) –Wireless media (unguided)

B5-48 Wire Media Wire media - transmission material manufactured so that signals will be confined to a narrow path and will behave predictably Three most commonly used types include: 1.Twisted-pair wiring 2.Coaxial cable 3.Fiber optic (or optical fiber)

B5-49 Wire Media

B5-50 Twisted-pair cable

B5-51 Coaxial Cable

B5-52 Fiber Optic

B5-53 Wireless Media Wireless media - natural parts of the Earth’s environment that can be used as physical paths to carry electrical signals

B5-54 E-Business Network Virtual private network (VPN) - a way to use the public telecommunication infrastructure (e.g., Internet) to provide secure access to an organization’s network Valued-added network (VAN) - a private network, provided by a third party, for exchanging information through a high capacity connection

B5-55 What is a VPN and why is it important? Virtual Private Network (VPN) –Uses public Internet to create appearance of private point-to-point connection –Client and server have point-to-point connection called a tunnel –Secure, encrypted communications

B5-56 WAN Using VPN