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 SwitchedEthernet 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 DetectionEthernet 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