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NETWORK CONNECTION HARDWARE

Chapter 3

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NETWORK INTERFACE ADAPTER

Provides the link between a computer and the network

Requires a device driver to perform both data-link and physical layer functions

Plugs into a bus slot or universal serial bus (USB) port on a computer

Also referred to as a network interface card (NIC)

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A NETWORK INTERFACE ADAPTER

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TRANSMISSION FUNCTIONS

Network interface adapters perform the following functions during data transmission: Data transfer, buffering, and encapsulation

Media Access Control (MAC)

Parallel/ serial conversion

Signal encoding and amplification

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HALF-DUPLEX AND FULL-DUPLEX MODES

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INSTALLING A NETWORK INTERFACE ADAPTER IN A COMPUTERTo install a network interface adapter:

1. Physically insert the network interface adapter card into the slot.

2. Configure the card to use the appropriate hardware resources.

3. Install the card’s device driver.

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A NETWORK INTERFACE ADAPTER IN A COMPUTER

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NETWORK INTERFACE ADAPTER DEVICE DRIVERS

Network interfaces require a device driver to provide the link between the computer and the interface.

Operating systems ship with device drivers for common interfaces.

Operating systems that support PnP detect and configure the interface automatically.

You can get drivers from the manufacturer’s Web site.

The driver configuration must match the interface’s resource settings.

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TROUBLESHOOTING A NETWORK INTERFACE ADAPTER

To troubleshoot the suspect network interface adapter, open the computer case and do the following: Verify that the interface is seated properly in

the bus slot.

Remove the card, clean the slot, and then reseat the card in the same slot or try another slot.

Test a different interface (known to be functional) in the same slot and in a different slot

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HUBS, REPEATERS, AND CONCENTRATORS

Hubs, repeaters, and concentrators are all physical layer devices that Amplify and repeat signals

Extend the distance of a network

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AN ETHERNET REPEATER

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10BASE-T AND 100BASE-X HUBS

10Base-T and 100Base-TX/100Base-T4 standards define Ethernet networks that function at 10 Mbps and 100 Mbps, using baseband signaling over twisted-pair wire.

10Base-T Maximum distance limitation for each connection:

100 meters, including workstation-to-hub and hub-to-hub connections

Can have up to four hubs connected to form a hierarchical star

Includes an internal crossover circuit

Uses an uplink port to form a hierarchical star

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10BASE-T AND 100BASE-X HUBS (CONT.)

100Base-TX and 100Base-T4 There are two types of hubs: Class I and

Class II.

The maximum distance for each node connection is 100 meters.

Class II hub-to-hub connections can be no more than 5 meters long.

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HUB CONNECTIONS

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10BASE-T HUB

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ROUTERS

Routers are network layer devices that connect LANs. Connect similar or different data-link layer LANs Must understand and support the network layer

protocol and addressing Perform fragmentation Strip the data-link header and footer off received

frames Add a new data-link header and footer before

transmitting frames Use routing protocols to build routing tables and

forward frames Define separate broadcast domains

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A SIMPLE ROUTED NETWORK

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A ROUTED INTERNETWORK

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GATEWAYS

Can include the functions of all seven layers of the OSI model

Connect dissimilar systems and protocols

Perform translation and conversion services

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SUMMARY

Network interface adapters provide the physical link between computers and the network.

Hubs are physical layer devices that amplify and repeat signals out all ports except the one they were received through.

Routers are network layer devices that forward datagrams between LANs.

Gateways translate and convert protocols between dissimilar systems.