04 Introduction to Computer Networking

hellhollowreadingNetworking and Communications

Oct 26, 2013 (3 years and 1 month ago)

70 views

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

10
Mbps

and

100
Mbps

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 (3
rd

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