Networks

Networks

LANS,

FastPoll True QuestionsAnswer A for True and B for False

• A wireless infrastructure network uses a centralized broadcasting device, such as a wireless access point or router.

• Wireless networks are less secure than wired networks.

• WEP, WPA, and PSK are examples of Wi-Fi encryption protocols to protect against jacking.

• Public key encryption uses a public key to encrypt messages, but a private key is required to decrypt messages.

Chapter 5: LANs and WLANs 2


Network Building Blocks

• Network Classifications• LAN Standards• Network Devices• Clients, Servers, and Peers• Physical Topology• Network Links• Communications Protocols

Question

• Networks come in many sizes and use many different technologies, yet they all need to communicate with each other. What is the key to network intercommunication?– A. Packet switching– B. Network protocols– C. Network topology– D. Peer-to-peer technology



Network Classifications

• Personal Area Network (PAN) – interconnection of personal digital devices or consumer electronics

• Local Area Network (LAN) – usually connects computers in a single building

• Metropolitan Area Network (MAN) – public high-speed network with range of about 50 miles

• Wide Area Network (WAN) – covers a large geographical area and typically consists of several smaller networks


LAN Standards

• LAN technologies are standardized by the Institute of Electrical and Electronics Engineers (IEEE) Project 802 – Local Network Standards– IEEE 802.3– ARCnet– Token Ring– FDDI– Ethernet


Network Devices

• Each connection point on a network is referred to as a node

• To connect to a LAN, a computer requires network circuitry, sometimes referred to as a network interface card (NIC)

• A network peripheral contains network circuitry to directly connect to a network

• A network device, or network appliance, is any electronic device that broadcasts network data, boosts signals, or routes data to its destination

Network Devices




5


Physical Topology The arrangement of devices in network: physical topology

– Star– Ring– Bus– Mesh– Tree

Similar networks can be connected by a bridge

Gateway -any device or software used to join two networks


Communication Protocol

• Rules for transmitting data from 1 node to another:– Divide messages into packets– Affix addresses to packets– Initiate transmission– Regulate flow of data– Check for transmission errors– Acknowledge receipt of transmitted data


Communications Protocols• A packet is a “parcel” of data that is sent

across a computer network

Circuit-switching technology vs.

Packet switching technology


Circuit-switched networks

require dedicated point-to-point connections during calls.

Packet-switched networks

moves data packets based on the destination address in each packet.

When received, packets are reassembled in the proper sequence to make up the message.


Communications Protocols• Every packet over a network includes the address

of its destination device

• MAC address – a unique number given to a NIC when manufactured

• IP address – a series of assigned numbers used to identify a

network device• Assigned by ISP as permanent or temporarily by DHCP

– Dynamic Host Configuration Protocols

http://en.wikipedia.org/wiki/Dhcp


Wired Networks

• Wired Network Basics• Ethernet• Ethernet Equipment• Ethernet Setup

Question

• You’re setting up a network in your home:– You want all 3 computers to access the cable modem for

Internet access. – Which of the following will give access to the cable modem

for your 3 computers

– A. A router– B. A network interface card– C. A file server– D. A HomePlug Ethernet port



Wired Network Basics

• Wired network

– uses cables to connect network devices– are fast, secure, and simple to configure– Devices tethered to cables have low mobility


Ethernet• Simultaneously broadcasts data packets to all

network devices– IEEE 802.3– CSMA/CD protocol

• Vary in speed from 10Mbps to 100Gbps

Ethernet Equipment



Ethernet Equipment

• Ethernet adapter (designed to support the Ethernet protocols)

• Network hub• Network switch• Network router• RJ45 connector

Ethernet Equipment

• Ethernet adapter [NIC]– (designed to support the Ethernet protocols)

Ethernet Equipment

• Network router

Ethernet Equipment

• RJ45 connector

Ethernet Setup


Wireless Networks

• Wireless Basics• Bluetooth• Wi-Fi• Wi-Fi Equipment• Wi-Fi Setup

Documents

Networks