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
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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
Network Adapters
• Devices connected to or installed in node:
– Internal card = Network interface cards (NIC) (A)
– Called ExpressCard on a laptop (B)
– External card = network adapter (one type is USB
adapter) (C)
• Enables communication between nodes
• Standard on new PC
C
A
B
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Network Navigation Devices
• Devices that control data flow
• Router:
– Route data between 2 networks
• Switch:
– Routes data across one network
– Router usually contains switches
• Come with w/ 4 or 8 ports, or more
• Repeater – amplifies signal
across longer wires
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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
• 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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Choosing a Peer-to-Peer Network
• Things to consider
-
Whether existing wiring is available
Whether you want wireless communications
How fast you want your network connection to be
How much money you can spend on your network
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 Ethernet Network 1 of 2
1. Each computer/node requires
a Ethernet network adapters
to connect the wire between
it and the router.
2. Computer/nodes are
connected to each other with
unshielded twisted pair
(Ethernet wire)
3. A node can be a printer or other
such device, as long as it has a
network card. (ex printer with
network card is $50-100 more)
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ehternet
Telephone
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Wired Ethernet Network 2 of 2
3.
Devices required
a)
b)
c)
4.
5.
Switch - keeps track of data
packets across 1 network
Router - keeps track of data
across several networks (ie –
yours and the Internet!);
Usually a home router contains a
switch– a and b above are taken
care of
Modem (DSL or Cable) required
Connect router to modem.
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Wireless Ethernet Network 1 of 2
Very similar to wired
requirements…
1. Each computer/node
requires a Ethernet wireless
network adapter to handle
signals
a)
Contains a transceiver (transmits
and receives signals); antenna
2. an Ethernet network that
uses radio waves instead of
wires
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Wireless Ethernet Network 2 of 2
3. Wireless router -- or gateway ( a wireless
router also has ports for “wired” computers)
4. Modem (DSL or cable)
5. Optional device –Wireless Access Point – if
reception is poor in parts of your house
Wireless network - other
• Ex: If your cordless phone works at 5 GHz
bandwidth it may interfere with 802.11n
wireless network that also operates at
5GHz. Solution: use 2.4 GHz phone.
• Con:
– sometimes a home does not lend itself to
wireless due to walls, metal objects, etc
– Wired 1G bps (Gigabit) networks are faster (for
video files, multi-player games)
• Pro: no wiring!
IEEE standards
• IEEE – Institute of Electrical and Electronic
Engineers
• 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
Configure software for network
1. Install (verify) network adapters on each
node.
2. Connect cable/DSL modem cable or tele
line to modem and connect PC to modem
(Verify Internet is live).
• If live, connect modem to router instead
(and PC to router too)
Go to next slide…
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Configure software for network
3. Connect PC and other nodes (PCs,
networkable printers etc) to router
4. Turn on all equipment in the following
order, wait 1 min after each one:
a. Cable/DSL modem
b. Router
c. All computers other nodes (PCS, printers, etc)
5. Run network wizards, adjust settings for
sharing (Control Panel > Network and
Sharing. Details left out)
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Configuring a Router to
Connect to the Internet
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•
•
•
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 ___ and
change password.
3. Enable security protocol (WEP or newer WPA2)
4. Restrict access via MAC filtering (Media Access
Control )
5. Limit your signal range.
6. Apply firmware upgrades
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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.
• Digital media receiver (DMR) - same as digital
media adapter; allows TV to be part of
network
• Network attached storage (NAS) – drive
accessible to network for graphic/video files
• Home media servers