3. What is a Network?
• Defined as two or more computing devices connected
together in such a way that they can share resources
• Resources:
• files
• folders
• printers
• disk drives
• etc.
3
4. What is a Network?
• A collection of computers or other hardware devices that are
connected together, either physically or logically, using special
hardware and software, to allow them to exchange information and
cooperate
4
5. What is Networking?
• Term that describes the process involved in designing,
implementing, upgrading, managing, and otherwise working with
networks and network technologies
5
6. Advantages of Networking
• Connectivity and Communication
• Data Sharing
• Hardware Sharing
• Internet Access
• Internet Access Sharing
• Data Security and Management
• Performance Enhancement and Balancing
• Entertainment
6
7. Disadvantages of Networking
• Cost of setup
• Management and administration costs
• Undesirable sharing
• Illegal or undesirable behavior
• Data security concerns
7
8. Basic Components of a Network
• Server
• core component of the network
• provides link to the resources necessary to perform any task
• Client
• requests and receives information over the network client
• depends primarily on central server for processing activities
• Circuit
• cables, ports and other devices that connect the server and the client
computers
8
9. Network Interface Card (NIC)
• Circuit board that fits in one of the computer’s internal expansion
slots
• Contains circuitry that handles sending, receiving, and error
checking of transmitted data
9
10. Key Points in Networking
• Important characteristics that influence transmission technologies
and communication protocols
• size
• shape
• Networks are classified according to area over which they extend
• Size and extension depend on number of nodes that need to
communicate, and where these nodes are in relation to each other
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11. Network Classifications
• PAN (personal area
network)
• refer to the
interconnection of
personal digital
devices or consumer
electronics w/n the
range of 30ft (10m)
and without the use
of wires or cables
11
12. Network Classifications
• LAN (local area network)
• data communications
network the connects
personal computers within a
very limited geographical
area
• school computer labs
• home networks
12
13. Network Classifications
• MAN (metropolitan
area network)
• public high-speed
network capable of
voice and data
transmission within
the range of 50mi
(80km)
• ISPs
• small cable TV
companies
• local telephone
companies
13
14. Network Classifications
• WAN (wide area
network)
• covers large
geographical area
and usually consists
of smaller networks
• nationwide banks
• large cable TV
companies
• multi-location
superstores
• internet
14
15. Network Topologies
• Architectural “drawings” to show the overall physical configuration
for a given communications system
• Indicates the access methods and governs the rules that are used to
design and implement the communication system
15
16. Network Topologies
• Bus topology
• Single electrical circuit
to which all devices in
network are connected
16
17. Network Topologies
• Star topology
• individual computers are
connected to a central
device such as a hub or a
switch
17
18. Network Topologies
• Ring topology
• a collection of separate point-to-
point links arranged to make a
ring
• each nodes NIC has one input and
one output connection
• so each node has two links
18
21. NETWORK TOPOLOGY CASE STUDY:
This will serve as your ACTIVITY 2.
SEARCH FOR ONE (1) CASE STUDY IN EITHER OF THE FOLLOWING
TOPOLOGY ARE PRESENT:
* BUS TOPOLOGY * STAR TOPOLOGY * RING TOPOLOGY
Take note what are the advantages and disadvantages of your chosen
topology based on your case study. Put it in Word, then save as
“<Lastname>_Activity2”
Be ready! I will call some students to present their research
23. Network Devices
• Sometimes referred to as a network appliance
• Any electronic device that broadcasts network data, boosts signals,
or routes data to its destination
24. Network Devices
• Node
• Each connection point on a network
• Usually contains:
• Computer
• Networked peripheral
• Network device
• Workstation
• Personal computer connected to a network
25. Network Devices
• Network Interface Card (NIC)
• Circuitry to connect to LAN
• Sometimes built-in in some personal computers
• Can be added to an expansion slot or USB port
• Networked peripheral
• Any device that contains network circuitry to directly connect to a network
• Examples: printers, scanners, storage devices
34. Network Links
• Links
• Communications channel
• Physical path or a frequency for signal transmissions
• Wired – cables
• Cat 5 or Cat 6 (max length of 100m)
• RJ45 connector
35. Network Links
• Bandwidth
• Transmission capacity of communications channel
• High-bandwidth (broadband) can carry more data than low-bandwidth
(narrowband)
• Digital bandwidth is measured in bits per second (bps)
• Analog bandwidth is measured in hertz (Hz)
36. Communications Protocol
• Protocol
• Set of rules for interacting and negotiating
• Communications protocol
• Set of rules for efficiently transmitting data from one network node to
another
• TCP/IP
• Transmission Control Protocol/Internet Protocol
• Internet data support and standards for LANs
37. Communications Protocol
• Aspects of network communications that communications protocol
handles
• Dividing messages into packets
• Affixing addresses to packets
• Initiating transmission
• Regulating flow of data
• Checking for transmissions errors
• Acknowledging receipt of transmitted data
38. Communications Protocol
• Packets
• A parcel of data that is sent across a computer network
• Contains:
• Address of sender
• Destination address
• Sequence number
• Some data
39. Communications Protocol
• Data are broken down into packets and reassembled in the destination
according to sequence number
40. Communications Protocol
• Circuit switching
• Used by some technologies like telephone system
• Dedicated private link between one telephone to another telephone for the
duration of the call
• Inefficient
41. Communications Protocol
• Packet switching
• Divides message into several packets that can be routed independently to
their destination
• Messages divided into equal-size packets are easier to handle than an
assortment of small, medium, large, and huge files
• Packets are shipped over the circuit on a first-come, first-served basis
44. Communications Protocol
• Routing of packets
• Each packet contains the address of the destination device
• Communications protocol specify the proper format of addresses
• Two commonly used addresses:
• MAC address
• IP address
45. Communications Protocol
• MAC address
• Media Access Control address
• Unique number assigned to a network interface card when it is
manufactured
• Used in low-level network functions and can also be employed to establish
network security
46. Communications Protocol
• IP address
• Internet Protocol address
• Series of numbers used to identify a network device (computers, servers,
peripherals, and devices)
• Originally used in the internet but used in LANs
• Example: 204.127.129.1
• Four groups of numbers separated by period
• Octet (eight bits in binary)
47. Communications Protocol
• IP address
• Assigned by ISPs or system managers
• Sometimes assigned by DHCP
• Dynamic Host Configuration Protocol
• Automatically distributes IP addresses
• Computers send a query to the network device acting as the DHCP server
• IP address is good for that session only