Understand the Understand the Components of a NetworkComponents of a NetworkMrs. WhaleyMrs. Whaley

Nodes and File ServersNodes and File Servers

Each device on a local area Each device on a local area network, such as a computer or network, such as a computer or printer.printer.

Each node is connected to a file Each node is connected to a file serverserver High-speed computers with large High-speed computers with large

hard drives that are used to store hard drives that are used to store large amounts of data.large amounts of data.

All nodes and file servers are All nodes and file servers are connected via physical media.connected via physical media.

Why should data be Why should data be centralized on a network?centralized on a network?

1.1. Gives users access to most up-Gives users access to most up-to-date datato-date data

2.2. Eliminates problem of same Eliminates problem of same data being duplicated on each data being duplicated on each user’s computeruser’s computer

Network Interface CardNetwork Interface Card

Connects a computer to a Connects a computer to a networknetwork

Controls data between Controls data between computer’s RAM and network computer’s RAM and network cable.cable.

Client Server NetworksClient Server Networks

One or more file servers stores One or more file servers stores most of the shared data and run most of the shared data and run the network operating system.the network operating system.

Network operating system – Network operating system – manages the LAN by manages the LAN by establishing and maintaining the establishing and maintaining the connections between the nodes connections between the nodes and the file server.and the file server. Common systems are Microsoft Common systems are Microsoft

Windows NT or XP Servers and Windows NT or XP Servers and Novell Corporation’s NetWareNovell Corporation’s NetWare

Network TopologyNetwork Topology

Physical arrangement of Physical arrangement of computers on a network.computers on a network.

3 most common3 most common BusBus StarStar ringring

Bus topologyBus topology A single cable runs the length of A single cable runs the length of

the network. the network. Each node connects to one Each node connects to one

cable.cable. Inexpensive, but entire network Inexpensive, but entire network

may crash from one cable being may crash from one cable being down.down.

Star TopologyStar Topology Each node connects to a hub Each node connects to a hub

through the file server.through the file server. Use more cable than a bus.Use more cable than a bus. Single cable will not crash Single cable will not crash

network.network.

Ring TopologyRing Topology Each node connects to the next in a Each node connects to the next in a

circular arrangement.circular arrangement. A token special set of data) travels A token special set of data) travels

from one computer to the next from one computer to the next around the circle.around the circle.

If a computer needs to send or If a computer needs to send or receive data, it must wait until the receive data, it must wait until the token gets to it.token gets to it.

Eliminates 2 computers transmitting Eliminates 2 computers transmitting data at the same time.data at the same time.

Ring Topology Cont.Ring Topology Cont.

ProtocolsProtocols

Standards that describe how the Standards that describe how the different devices on a network different devices on a network communicate w/ each other.communicate w/ each other.

Data must travel through Data must travel through channels before reaching media channels before reaching media and vice versa.and vice versa.

Each layer performs its own Each layer performs its own function and has its own set of function and has its own set of protocols.protocols.

LAN STANDARDSLAN STANDARDS

All network elements combined.All network elements combined. Ethernet – used with bus and Ethernet – used with bus and

star topologies, twisted pair or star topologies, twisted pair or fiber optic cables and a NIC.fiber optic cables and a NIC.

Fast Ethernet – transmits data Fast Ethernet – transmits data at 100 Mbps instead of 10 Mbpsat 100 Mbps instead of 10 Mbps

LAN standards cont.LAN standards cont.

Token ring – 2Token ring – 2ndnd most widely most widely used network.used network.

LocalTalk – Macs use this.LocalTalk – Macs use this. Ordinary phone cables arranged in Ordinary phone cables arranged in

bus topology.bus topology. Data transmits at only 230 KBPS.Data transmits at only 230 KBPS. Slower than Ethernet or token ringSlower than Ethernet or token ring