SPRING 2016 Lesson - 4 Networks Communication CSE 101

2 This Lesson Includes Following section Networking BasicsDatabase Management System

3 Networking Basic Why do we need Networks? Main Benifit of Networks Simultaneous Access Shared Peripheral Devices Personal Communication Easier Backup Read/write Read only What is Network? A network is a group of computers that are connected to each other by various means, so that they may communicate with each other. The internet is the largest network in the world.

4 Networking Basic – How Networks are Structured Server-Based Networks Mainfram Client/Server Networks LANWANMANPANHANGAN Peer-to-Peer Networks MP3’s / Vedio/etc Home Network Network can be catagorized in 3 catagory

5 Networking Basic – Local Area Network - LANs  A network serving a home, building or campus is considered a Local Area Network (LAN). Usually owned by a same organization.  LANs are designed to share resources amongst workstations or PCs.  Data rates much higher now, 100 or 1000 Mbps.

6 Networking Basic – Wide Area Network - WANs A WAN is two or more LANs connected together. The LANs can be many miles apart and still connected together using devices such as bridges, routers, or gateways, which enable them to share data. To cover great distances, WANs may transmit data over leased high- speed phone lines or wireless links such as satellites. Type of Wide Area Network Switched WAN Point-to- Point WAN

7 Networking Basic – Metropolitan Area Network - MAN  When the LANs that you want to connect are not far apart, just blocks away, then you can make a MAN (Metropolitan Area Network).  The main difference between a WAN and a MANs is the speed of the connection. Because the LANs are so close in a MAN, high speed fiber-optic cables are affordable.

8 Networking Basic – Peer-to-Peer (p2p) Network In a peer-to-peer network, all nodes have an equal relation to one another. Each node usually has access to some resources on other nodes, so users can share files, programs, or devices on other users' systems. Some peer-to-peer networks use a server, but some do not. Example: Some popular p2p software are: Napstar Mirc Bit Torrent eMula DC++

9 Networking Basic – Network Media & Hardware All networks are made up of basic hardware building blocks to interconnect network nodes. Some common network hardware are: Network Interface Card (NIC) RepeatersHubsBridgesSwitchesRouters

10 Networking Basic – Wires In a network, the media are the wires, cables and other means by which data travels from its source to its destination. The most common network media are twisted-pair cable, coaxial cable, fiber-optic cable, and wireless links. Twisted – Pair Cable Coaxial Cable Fiber-Optic Cable Wireless Links

11 Networking Basic – Network Software A network operating system (NOS) is the group of programs that manages the resources on a network. Common network operating systems for PC-based networks include: Novell NetWare Microsoft Windows NT Server Microsoft Windows 2000 Banyan VINES AppleShare Linux

12 Networking Basic – Internetwork Internetwork Two or more networks or network segments connected using devices that operate at layer 3 (the 'network' layer) of the OSI Basic Reference Model, such as a router. Any interconnection among or between public, private, commercial, industrial, or governmental networks may also be defined as an internetwork. In modern practice, the interconnected networks use the Internet Protocol. There are at least three variants of internetwork, depending on who administers and who participates in them: 1.Intranet 2.Extranet 3.Internet Intranet: An intranet is a computer network that uses Internet Protocol technology to securely share any part of an organization's information or network operating system within that organization. It is the connection of computer networks in a local area. The term is used in contrast to internet, a network between organizations, and instead refers to a network within an organization. [See more on User Data Internet Request Response Request (1) Response with tag (2) Request (3) Response (4) Internet Request Response

13 Networking Basic – Internetwork Extranet: An extranet is a computer network that allows controlled access from the outside, for specific business or educational purposes. In a business-to- business context, an extranet can be viewed as an extension of an organization's intranet that is extended to users outside the organization, usually partners, vendors, and suppliers, in isolation from all other Internet users. [See more on Internet: The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite (TCP/IP) to serve billions of users worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic, wireless and optical networking technologies. The Internet carries an extensive range of information resources and services, such as the inter-linked hypertext documents of the World Wide Web (WWW) and the infrastructure to support . [See more on

14 Networking Basic – Internetwork Fig: Intranet [1] Fig: Extranet [2] Fig. Internet [3]

15 Network Topology Topology: Physical layout of network devices Types of topology: MeshBusRingStarHybrid

16 Any Question SPRING 2016