Transcript Introduction to Computer Networking

Introduction
to
Computer Networking
Wireless Network
Wired Network
Hybrid Network
Direct Connect
Powerline Network
Basics (pcmag.com)
• Definition of: Ethernet
The standard local area network (LAN) access method. A
reference to "LAN," "LAN connection" or "network card"
automatically implies Ethernet.
• Most new computers come network ready with Ethernet
built in. For machines without a network connection,
Ethernet adapters can be added via USB or PC Card or by
plugging an Ethernet card into a free PCI bus slot inside
the case.
Basics
•
Megabits Per Second: 10, 100, 1,000 and 10,000
A 10/100 Ethernet port supports two speeds: 10 Mbps (10Base-T) and 100 Mbps
(100Base-T). Computers also come with 10/100/1000 ports, which includes Gigabit
Ethernet at 1 Gbps (1,000 megabits). Ethernet devices negotiate with each other and
transmit at the highest speed possible. For high-speed backbones in metropolitan and
wide area networks, 10 Gigabit Ethernet (10,000 megabits), the fastest Ethernet, is also
used (see 10 Gigabit Ethernet).
Shared or Switched
Ethernet is wired in a star configuration with a hub or switch in the middle. Hubs, which
predated switches, are shared media devices. All stations attached to the hub share the
total bandwidth. Switches provide each sender and receiver pair with the full
bandwidth and are significantly faster than hubs (see switched Ethernet). Like the client
machines, Ethernet switches and hubs also support 10/100 and 10/100/1000 speeds.
Collision Detection
Ethernet uses the CSMA/CD technology to broadcast each frame onto the physical
medium (wire, fiber, etc.). All stations attached to the Ethernet are "listening," and the
station with the matching destination address accepts the frame and checks for errors.
Ethernet is a data link protocol (MAC layer protocol) and functions at layers 1 and 2 of
the OSI model.
Basic Equipment: Cards/Cables
Basic Equipments
•
“SWITCH” and a “HUB”?
•
A 10/100 mbps is a good choice these days for basic home networks. This kind of hub
will allow you to hook up 10Mbps and 100Mbps devices and network cards on the
same network. Furthermore, even if the devices communicate at different speeds, the
hub will allow them to talk. Now that the prices have come down to under $50.00, the
versatility and speed of these hubs can not be beat.
•
10/100 Ethernet Hubs are only half duplex - each client can only send OR receive data
at a particular time. To take full advantage of your 10/100 Ethernet cards, look into an
Ethernet Switch. A switch can operate at full duplex allowing your computers to send
and receive at the same time.
•
Ethernet switches allow your Ethernet cards to operate in Full Duplex mode instead of
Half Duplex. Full Duplex means that you can be sending and receiving data at the same
time. Switches also route traffic directly between ports instead of broadcasting traffic
across all ports. This basically means that each port on a switch gets dedicated
bandwidth instead of shared bandwidth. When transferring large files between
multiple computers, this can make a big difference in how well your lan operates.
Hubs & Switches
Routers
• A device that forwards data packets along
networks. A router is connected to at least
two networks, commonly two LANs or WANs
or a LAN and its ISP’s network. Routers are
located at gateways, the places where two or
more networks connect.
Routers, Routers, Routers
ISPs, WAN, LAN
• ISP – Internet Service Provider
– Verizon FIOS, DSL, Cable Internet, AOL
• WAN – Wide Area Network
– The Internet, Two or more networks
• LAN – Local Area Network
– Small local area, a home network for example
IP Address
• An IP address (or Internet Protocol address) is a unique address that
certain electronic devices use in order to identify and communicate
with each other on a computer network utilizing the Internet Protocol
standard (IP)—in simpler terms, a computer address. Any participating
network device—including routers, switches, computers, printers,
Internet fax machines, and some telephones—can have its own
address that is unique within the scope of the specific network. Some
IP addresses are intended to be unique within the scope of the global
Internet, while others need to be unique only within the scope of an
enterprise.
Most common home network
Connecting a network
• Order Internet from an ISP
• Wait for ISP order/service date
– DSL, Cable, FIOS 1-2 weeks
• Self Install (DSL package)
– DSL modem, CAT 5 cable, phone filters
• Professional Install (Cable, FIOS)
– Modem, CAT 5 cable
• Connect to a computer to test the connection
Connecting a network
•
•
•
•
•
Turn off computer, modem
Connect all the computers to the router
Turn on computers, modem, router
Test Internet connect on computers
Setup wireless network
– Choose name
– Choose security format
– Connect wireless devices to Internet
Active connection ?
Router Interface
• Connect to Router with web browser
– Default address, username, password
Router Configuration
Router Configuration (wireless)
What to set ?
• On/Off (Off if 1 PC or all device wired)
• SSID (name) (on or off)
• Channel
– Use Auto or NOT 1, 6, 11
• Security
– WEP
• 64bit, 128bit (10 or 20 character long)
• Key 1-4
– WPA-PSK
• More secure, bit more work
• MAC-based access ? (both wired and wireless)
– Use ipconfig to lookup
– Stickers on the device
WAN ?
Info
given by
the ISPs
WAN Settings
• WAN – provided by ISP
– Static / Dynamic Service
– Static – always the same IP address
• More expensive
• Business, Organizations
– Dynamic – changes IP address
• Standard Service
• Most home uses
LAN Configuration
DHCP
Advanced Tools ?
Change your password
Status Screen
Devices on your network
Devices, Devices, (what can you
use)
• PDA, Cell Phones, Notebooks, Printers, Hard
drives, cameras, robots
Share Folders & Printers
Sharing Folders & Printers
Sharing Folders & Printers
Software based firewalls
(Windows)
Software based firewall (3rd party)
• Zone Alarm
• Norton
Personal
Firewall
• McAfee
Personal
Firewall
• PC-Cillin
Internet
Security
Share your wi-fi connections
• Community wi-fi services
– Starbucks
– Mamaks
• Share your wi-fi from your home
• Access other members wi-fi when traveling