Информатика

1.1 NETWORK COMPONENTS

You will: describe the purpose of network components (modem, routers, switches...). 

What is the physical part of a network? 

Modems

A modem connects to the Internet through an Internet Service Provider (ISP). There are three basic types of modems. Modems convert a computer’s digital data into a format that can be transmitted on the ISP’s network. An analog modem converts digital data to analog signals for transmission over analog phone lines. A digital subscriber line (DSL) modem connects a user’s network directly to the digital infrastructure of the phone company. A cable modem connects the user’s network to a cable service provider, which typically uses a hybrid fiber coax (HFC) network.

Hubs

Hubs receive data on one port and then send it out to all other ports. A hub extends the reach of a network because it regenerates the electrical signal. Hubs can also connect to another networking device, such as a switch or router, which connects to other sections of the network. Hubs are used less often today because of the effectiveness and low cost of switches.

Switches

A switch microsegments a LAN. Microsegmenting means that switches filter and segment network traffic by sending data only to the device to which it is sent. This provides higher dedicated bandwidth to each device on the network. If there is only one device attached to each port on a switch it operates in FullDuplex mode. 

Wireless Access Points

Wireless access points provide network access to wireless devices, such as laptops and tablets. The wireless access point uses radio waves to communicate with the wireless NIC in the devices and other wireless access points. An access point has a limited range of coverage. Large networks require several access points to provide adequate wireless coverage. 

Routers

Routers connect networks. Routers use IP addresses to forward traffic to other networks. A router can be a computer with special network software installed, or a device built by network equipment manufacturers. In larger networks, routers connect to switches, which then connect to LANs. The router serves as the gateway to outside networks. 

Poll

Activity

What is the difference between the Hubs, Bridges, and Switches?

• 1. Uses IP addresses to forward traffic to other

• 2. Resides between two or more networks and protect data and equipment on a network from unauthorized access.

• 3. Filters and segments network traffic by sending data only to the device to which it send.

• 4. Provides network access to device that use radio waves to communicate with other device.