Understand the Components of a Network Mrs. Whaley

Nodes and File Servers Each device on a local area network, such as a computer or printer. Each device on a local area network, such as a computer or printer. Each node is connected to a file server Each node is connected to a file server High-speed computers with large hard drives that are used to store large amounts of data. High-speed computers with large hard drives that are used to store large amounts of data. All nodes and file servers are connected via physical media. All nodes and file servers are connected via physical media.

Why should data be centralized on a network? 1. Gives users access to most up- to-date data 2. Eliminates problem of same data being duplicated on each user’s computer

Network Interface Card Connects a computer to a network Connects a computer to a network Controls data between computer’s RAM and network cable. Controls data between computer’s RAM and network cable.

Client Server Networks One or more file servers stores most of the shared data and run the network operating system. One or more file servers stores most of the shared data and run the network operating system. Network operating system – manages the LAN by establishing and maintaining the connections between the nodes and the file server. Network operating system – manages the LAN by establishing and maintaining the connections between the nodes and the file server. Common systems are Microsoft Windows NT or XP Servers and Novell Corporation’s NetWare Common systems are Microsoft Windows NT or XP Servers and Novell Corporation’s NetWare

Network Topology Physical arrangement of computers on a network. Physical arrangement of computers on a network. 3 most common 3 most common Bus Bus Star Star ring ring

Bus topology A single cable runs the length of the network. A single cable runs the length of the network. Each node connects to one cable. Each node connects to one cable. Inexpensive, but entire network may crash from one cable being down. Inexpensive, but entire network may crash from one cable being down.

Star Topology Each node connects to a hub through the file server. Each node connects to a hub through the file server. Use more cable than a bus. Use more cable than a bus. Single cable will not crash network. Single cable will not crash network.

Ring Topology Each node connects to the next in a circular arrangement. Each node connects to the next in a circular arrangement. A token special set of data) travels from one computer to the next around the circle. A token special set of data) travels from one computer to the next around the circle. If a computer needs to send or receive data, it must wait until the token gets to it. If a computer needs to send or receive data, it must wait until the token gets to it. Eliminates 2 computers transmitting data at the same time. Eliminates 2 computers transmitting data at the same time.

Ring Topology Cont.

Protocols Standards that describe how the different devices on a network communicate w/ each other. Standards that describe how the different devices on a network communicate w/ each other. Data must travel through channels before reaching media and vice versa. Data must travel through channels before reaching media and vice versa. Each layer performs its own function and has its own set of protocols. Each layer performs its own function and has its own set of protocols.

LAN STANDARDS All network elements combined. All network elements combined. Ethernet – used with bus and star topologies, twisted pair or fiber optic cables and a NIC. Ethernet – used with bus and star topologies, twisted pair or fiber optic cables and a NIC. Fast Ethernet – transmits data at 100 Mbps instead of 10 Mbps Fast Ethernet – transmits data at 100 Mbps instead of 10 Mbps

LAN standards cont. Token ring – 2 nd most widely used network. Token ring – 2 nd most widely used network. LocalTalk – Macs use this. LocalTalk – Macs use this. Ordinary phone cables arranged in bus topology. Ordinary phone cables arranged in bus topology. Data transmits at only 230 KBPS. Data transmits at only 230 KBPS. Slower than Ethernet or token ring Slower than Ethernet or token ring