Transcript Networking Fundamentals - Erie Community College

Chapter 7 - Networking Fundamentals
• Computer network:
– Two or more computers connected together
• Each is a Node (other nodes: printers, network
devices, such as a router, etc
• Benefits of a network:
– Sharing resources
– Transferring files
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Network Architecture
• Network designs:
– Individual PC controlled, local control
• Peer-to-peer (P2P)
– Central control
• Client/server
Peer-to-peer
Client/
server
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Peer-to-Peer Networks
• Use for < 10 computers
for home and small office
networks
• Nodes communicate
with each other:
– Peers
• Share peripheral devices:
– Printers
– Scanners
3
Client/Server Networks
• Used for > 10 computers
• Client computers:
– Users
• Server computers:
– Provide resources to clients
– Central network control
• Internet
– A large, multiserver,
multiclient network.
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HANs and LANs
• Home area network (HAN)
– Connects digital devices within a home
• Local area network (LAN)
– Nodes are within a small geographic region
• Schools
• Small businesses
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WANs and MANs
• Wide area network (WAN)
– LANs connected over long distances
• A few miles to thousands of miles
• Uses telecommunications lines
• Metropolitan area network (MAN)
– Provides access within a specific geographic
region, such as a city
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•
•
•
•
Network Components
Transmission media
Network adapters
Navigation devices
Software
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Transmission Media
• Provides communications channel between nodes
• Forms of media (wire):
– Twisted pair (copper)
• telephone
• ethernet
– Coaxial cable(copper)
– Fiber-optic (FIOS)
– Radio wave (wireless)
• Bandwidth:
– Data transfer rate (max)
– Throughput (actual speed
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Ethernet wire
• UTP – unshielded twisted pair, made of copper
• 4 pairs of wires (8 total wires) are twisted to
reduce interference (static); RJ-45 connector
• Compare to telephone wire which has 2 pairs
of copper wires; RJ-11 connector
• connector Max line 328 ft, don’t bend wire a lot, lie along
edges of room.
• Wires, and hardware need to be at same standard
• 1000 M = 1G
It’s
6a, not 7,
in Tech In
Action 8e
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Network Adapters (1)
• A device that enables communicate between
nodes on network
• Types:
– Wired network adapter (contains Ethernet port!)
– Current standard is that most laptops have wired
and wireless network adapters; desktops usually
wired network adapter
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Network Adapters (2)
• Adapter or card, interchangeable words; Types:
– Internal card = Network interface cards (NIC) (A)
– Network card for laptop (B)
– External card = network adapter (one type is USB
adapter) (C)
– Wireless network card(left pic)
• Enables communication between nodes
C
A
B
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Network Navigation Devices
• Router: Routes data between 2 networks
• Switch: Routes data across one network
• What is referred to as a router (or wireless router)
these days…
– Contains the switch and
– Usually contains the modem too
– Usually has wired and wireless capability; comes
with 4 ports
– In other words, one device contains all necessary
capabilities.
– Repeater – Amplifies signal across longer wires
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The common (wireless) router
Router allows for
wired and wireless
connections; ports
for wired
connections
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Networking Software
• Peer-to-Peer Software:
• Built into operating systems that support
networking
– Windows XP, Vista, Windows 7
– Mac OS , Linux
• Home Network Server (“server” in
the name yet still used on P2P; for media files)
• Client/Server Software (central services and
security)
• Network operating system (NOS) software
– Windows XP Professional,(Vista Ultimate?)
– Windows Server 2008
– SUSE Linux Enterprise
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Wired, wireless speeds
Comparing the Major Types of Home Networks
Wired
Ethernet
Power-Line
Wireless
802.11g
Wireless
802.11n
Maximum data transfer rate
(bandwidth)
100 Mbps to
1 Gbps
200 Mbps
54 Mbps
540 Mbps
Relative installation and
equipment costs for networking
two computers
$
$$
$
$$
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Wired/wireless Ethernet Network
1. Network adapter (wireless network adapter) each node requires one to connect to router.
a.
Wired nodes connect w/ Ethernet wire; Wireless nodes connect
with radio frequencies
2. Wireless router -- or gateway ( a wireless router also has
ports for wired computers)
3. Modem (DSL or cable)
4. Optional device –Wireless Access Point – if reception is
poor in parts of your house
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Wireless - other
•
Wireless router …
– Connects up to 253 wireless, yet they SHARE
BANDWIDTH
– Contains a transceiver (transmits and receives
signals) and antenna
• Wireless interference:
– sometimes wireless networks have interference
from cinderblock, other building materials, other
electronic devices,
• Wired 1G bps (Gigabit) networks are faster (for
video files, multi-player games). Otherwise consider
wired for media devices (TV, etc)
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IEEE standards
• IEEE – Institute of Electrical and Electronic Engineers.
• Set electronic standards including those for Ethernet
networks
• 802.3 standard – wired networks
• 802.11 standard – wireless networks:
– 802.11a, b ( older and < 54 M bps)
– 802.11g ( = 54 M bps)
– 802.11n ( 540 M bps)
• Rec’d - all components from same manufacturer
• Cards, wires, devices must match to get that
corresponding speed, but backwards compatible
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Create the network 1/2
1. Install a network adapter on each node, (or verify
that each one has one)
2. Connect coaxial cable to cable modem (or
telephone line to DSL modem). Connect PC to modem
a. Verify that Internet is live on PC. If live, then
connect modem and router together. And
disconnect PC above and reconnect to router.
3. Connect all other nodes to router (laptops,
desktops, networkable printers, tablets, etc.)
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Create the network 2/2
4. Turn on the following in this order ,
waiting a few minutes in between:
a. Cable/DSL modem
b. Router (Then wait a few minutes.)
c. All computers other nodes (PCS, printers, etc)
5. Open Control Panel> Network and Sharing.
•
•
With wired connection (and Windows 7), you should
be connected to home network automatically
With wireless connection, click on Connect to a
network option, (and enter security pass phrase if
you already secured your router, see 2 slides ahead.)
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Configuring a Router to
Connect to the Internet
•
•
•
•
Contact ISP for special settings
Access router from Web browser
Enter username and password
Use router’s wizard to set up connection using
settings and info provided by ISP
• Test Internet connection speed
– Speedtest.net
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Secure your wireless network
SECURE YOUR WIRELESS ROUTER:
1. Change SSID to unique one (and/or turn off
broadcasting of it.)
2. Change default username from “admin” to a secure
username you desire. And change the password.
3. Enable security protocol (WEP or newer WPA2)
4. Restrict access via MAC filtering (MAC =Media Access Control )
5. Limit your signal range.
6. (Apply firmware upgrades – technical step)
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Other
• Hub – a switch is a smart hub. Hub transmits
signals to all nodes whereas switch transmits
only to requesting nodes.
• New devices, television and related media
devices, now come with network adapters to
connect to your network
• Network attached storage (NAS) – drive
accessible to network for graphic/video files
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