Chapter 3 How to build a network?

2 Objectives What is a Network? IP Addresses Key Components of a Network (NIC) Factors in Designing a Network

3 What is a Network? A connection between at least two computers for the purpose of sharing resources (files, DB, printer etc.) Types: –Peer to Peer –Client and Server

4 Peer-to-Peer Network Computers linked together as equals No centralized control Share resources on the same network in any way and any time Promotes institutionalized chaos < 10 computers

5 Client/Server Network Server – designed to address a client’s request Client – any computer connected to a server within a network A cluster of computers (called clients) connected to one or more servers to form a network Allow authorized user to access any programs/application resided on the server

6 IP Address Why? Identify network computer A host number that identifies itself to other hosts Find your computer’s IP: cmd -> ipconfig E.g Host Name –Human-friendly internet addresses –E.g. ema3z.mcintire.virginia.edu

7 URL vs. IP Zone –Three-letter kind (com, gov, edu) –Two-letter kind (ca, uk, jp) –New general-purpose zones (firm, store) –Last (rightmost) part of a domain name preceded by a dot

8 Data Transfer over Network Packet –Grouping of data for transmission on a network –Large messages are split into a series of packets for transmission Protocol –A rule governing how communication should be conducted between two parties, two computers, or a sources and a destination –Internet Protocol Set of rules used to pass packets

9 Key Components of A Network Network Interface Card (NIC) Routers

10 Network Interface Card Installed in a slot with a cable plugged into the back Plugged into a wall jack connection or into the hub/switch directly Modem –Converts digital signals into analog form for transmission and incoming analog signals into digital signal across the telephone line

11 Routers LAN to LAN Evaluate network traffic and stop local traffic from causing congestion Filter out packets that need not be received Expensive and difficult to operate

12 Factors in Designing a Network Capacity – how many? Cost – how much? Potential growth (scalability) Security – how safe?

13 Test help What is a client? What is the function of the Internet layer? What is a microwave transmission? What is TCP? What is a macro?

14 Summary What is a Network? IP Addresses Key Components of a Network (NIC) More Factors in Designing a Network