2.  Computer Networking Computer Networking  Networking terminology Networking terminology  Client Server Model Client Server Model  Types of Networks Types of Networks  Local Area Network (LAN) Local Area Network (LAN)  Wide Area Networks (WAN) Wide Area Networks (WAN)  Metropolitan Area Network (MAN) Metropolitan Area Network (MAN)  Firewalls Firewalls  Network Addresses Network Addresses  Internetwork Internetwork

3.  Computer network A collection of computing devices that are connected in various ways in order to communicate and share resources Usually, the connections between computers in a network are made using physical wires or cables However, some connections are wireless, using radio waves or infrared signals back

4.  The generic term node or host refers to any device on a network  Data transfer rate The speed with which data is moved from one place on a network to another  Data transfer rate is a key issue in computer networks back

5.  Computer networks have opened up an entire frontier in the world of computing called the client/server model Figure 15.1 Client/Server interaction

6.  File server A computer that stores and manages files for multiple users on a network  Web server A computer dedicated to responding to requests (from the browser client) for web pages back

7.  Local-area network (LAN) A network that connects a relatively small number of machines in a relatively close geographical area  Wide-area network (WAN) A network that connects two or more local-area networks over a potentially large geographic distance  Metropolitan-area network (MAN) The communication infrastructures that have been developed in and around large cities back

8.  Contains printers, servers and computers  Systems are close to each other  Contained in one office or building  Organizations often have several LANS back

9.  Two or more LANs connected  Over a large geographic area  Typically use public or leased lines ◦ Phone lines ◦ Satellite  The Internet is a WAN back

10.  Large network that connects different organizations  Shares regional resources  A network provider sells time back

11. Firewall A gateway machine and its software that protects a network by filtering the traffic it allows Access control policy A set of rules established by an organization that specify what types of network communication are permitted and denied

12. back

13. Class A: first byte network address and three bytes for host number Class B: first two bytes for network address and two bytes for host number Class C: first three bytes for network address and one byte for host number

14.  Protocol  Networks are usually classified using three properties:  Topology  Protocol  Architecture back

15.  Intranet ◦ An intranet is a set of networks, using the Internet Protocol and IP-based tools such as web browsers and file transfer applications, that is under the control of a single administrative entity. ◦ Most commonly, an intranet is the internal network of an organization  Extranet ◦ An extranet is a network or internetwork that is limited in scope to a single organization or entity but which also has limited connections to the networks of one or more other usually, but not necessarily, trusted organizations or entities ◦ by definition, an extranet cannot consist of a single LAN; it must have at least one connection with an external network.

16.  Internet ◦ The Internet consists of a worldwide interconnection of governmental, academic, public, and private networks based upon the networking technologies of the Internet Protocol Suite ◦ It is the successor of the Advanced Research Project Agency Network(ARPANET) developed by DARPA of the U.S Department of Defense ◦ The Internet is also the communications backbone underlying the World Wide Web (WWW). back

17. Thank You