MET 105: Intro to Info systems and networking

What is a Network?

Two or more connected computers that can share resources like data and applications, office machines, an Internet connection, or some combination of these. Basically a collection of Hardware, Software, and people sharing information and ideas

What does CPU stand for?

Central processing unit

What is a CPU? What does it do?

The computer’s brain and is electronic machinery that carries out instructions from programs that allow a computer or other device to perform its tasks.

What is a Motherboard? What does it do?

The backbone that ties the computer's components together at one spot and allows them to talk to each other.

What does RAM stand for?

Random-Access Memory

What is RAM?

A form of computer memory that can be read and changed in any order.

What does RAM do?

• handles your temporary memory (all the data you are currently using)

• The more RAM you have the better your computer will do in terms of performance.

• RAM is usually installed in pairs

What are the TWO types of RAM?

SRAM, DRAM

What is the difference between SRAM and DRAM?

• SRAM is static, it does not need to be refreshed. DRAM is dynamic and needs to be refreshed often.

• SRAM uses less power, and the memory can be accessed quickly, however DRAM is cheaper and offers greater memory capacity.

What does ROM stand for?

Read-Only Memory

What is ROM? What does it do?

A non-volatile memory type. This means it receives data and permanently writes it on a chip, which lasts even after you turn off your computer. The data is coded not to be overwritten

What is a Hard Drive? What does it do?

It is where all your permanent computer data is stored. Whenever you save a file, photo, or software to your computer, it's stored in your hard drive

What is a Peripheral/peripheral device? What does it do?

An auxiliary device used to put information into and get information out of a computer

What is I/O

Input/output

• It refers to how computers communicate with the outside world.

• This communication occurs through sending and receiving data from peripheral devices.

What do Application Softwares do?

• Acts as an interface for application programs

• Software that enables the functions and use of a device

• Accomplish user tasks

Examples: Word processing, Spreadsheet, Data

What are the types of Cabling?

• Coaxial

• Twisted Pair

• Fiber Optic

• Plenum Rated

What is the most common cable type used today? And why?

Unshielded twisted pair

• It’s cheaper than other types of cabling.

• It’s easy to work with.

• It allows transmission rates that were impossible 10 years ago.

What digital signals do Fiber Optic cables transmit

light impulses, NOT electricity

What are the two modes Fiber Optic cables come in?

Single mode fiber (SMF) & multimode fibers (MMF)

What is the difference between SMFs and MMFs?

• Multimode fiber is most often used for shorter-distance applications and single-mode fiber for spanning longer distances.

• They have different numbers of light rays that are carried

What are the pros of Fiber Optic cables?

• Is completely immune to EMI and RFI

  •Can transmit up to 40 kilometers (about 25 miles)

What are the Cons of Fiber Optic cables?

•Is challenging to install

•Is more expensive than twisted-pair

•Troubleshooting equipment is more expensive than twisted-pair test equipment

•Is harder to troubleshoot

What NEC specifications do Plenum rated cables need to comply with?

Flammability and smoke density: need to be coated in flame-retardant, low smoke materials such as polyvinyl chloride (PVC).

What is Topology?

• the physical and logical arrangement of nodes and connections in a computer network, which governs how data flows between devices.

• the arrangement of devices (nodes) and connections (links) in a computer network

What is Ring Topology?

When all devices are connected to each in a virtual ring. 

It does not have to be terminated.

What is Star Topology?

The most popular topology, each device has a dedicated connection to the hub or switch.

What is Bus Topology?

When signals from each device travel on a bidirectional bus. 

Utilizes CSMA/CD software the sense when a line is busy. 

Cabling has to be terminated at the ends.

What is Mesh Topology?

When each computer has a dedicated connection to every other computer on the network.

What are Hybrid networks?

Networks that are designed to take advantage of the strengths of each combined network. Star/Bus and Star/Ring are two examples of Hybrid Networks.

What does CDMA/CD stand for?

Carrier Sense Multiple Access/Collision Detection

What are CDMA/CDs are? What do they do?

• s software that senses when the line is busy, to avoid collisions and loss of data.

• Listens to see if the line if it is being used, systems waits for a random amount of time then retries.

What does PAN stand for?

Personal Area Network

What is PAN? What does it do?

• a network that is used for communicating among computers and computer devices (including telephones) nearby around a few meters within a room.

• It can be used for communicating between the devices themselves or for connecting to a larger network such as the internet.

What does LAN stand for?

Local Area Network

What is LAN? What does it do?

• a network that is used for communicating among computer devices, usually within an office building or home

• enable the sharing of resources, such as files or hardware devices, that may be needed by multiple users 

Pros of LANs

• limited in size, typically spanning a few hundred meters, and no more than a mile.

• Is very fast, with speeds from 10 Mbps to 10 Gbps

• Requires very little wiring, typically a single cable connecting to each device.

• Has lower cost compared to MAN’s or WAN’s

What are nodes?

• any device connected to the network. This could be a computer, a printer etc.

• linked together with a certain topology in LANs

What are Hubs

A networking device that connects multiple segments of the network together

What are Network Interface cards (NIC)?

the circuit board that is used to connect computers to the network. 

In most cases, this is an Ethernet card plugged in a computer’s motherboard.

What are Network operating systems (NOS)?

• The software that enables users to share files and hardware and communicate with other computers. 

• Examples of NOS include: 

Windows XP

Windows NT

Sun Solaris

Linux

etc...

How is resource sharing accomplished in a LAN?

•Token based access

•CSMA/CD

What does MAN stand for?

Metropolitan Area Network

What is MAN?

A network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN)

What does WAN stand for?

Wide Area Network

What is WAN?

A geographically distributed network composed of local areas networks (LANs) joined into a single large network using services provided by common carriers.

What is Wireless networking?

A computer network that uses wireless data connections between networks nodes

• They use the same network scaling names to depict the size of a network.

  PAN, MAN, WAN, and LAN

Pro of wireless networks

• Avoid the costly process of introducing cables into a building or as a connection between various equipment locations

Extra info: Admin telecommunications networks are generally implemented and administered using radio communication.

What do wireless networks use to communicate with other devices

Radio frequencies (RF)

What are the hardwares of wireless networks?

Wireless NICs, Wireless Access Points

What is the software for wireless networks?

Device drivers: talks to the wireless NIC and configuration utility.

What are network devices?

They are the physical appliances required for communication and interaction between computers on a computer network

What are Repeaters? What do they do?

Repeaters are simple devices that act as signal amplifiers; they extend or boost signals by forwarding wireless signals from the router to cover a larger area

What are network hubs? What do they do?

Hubs are simple devices connecting multiple computers. 

A network hub is a node that broadcasts data to every computer or Ethernet-based device connected to it.

What are network switches? What do they do?

A network switch connects users, applications, and equipment across a network to communicate with one another and share resources. 

Network switches act as central connection points for network devices.

What does TCP/IP stands for?

Transmission Control Protocol/Internet Protocol

What is a TCP/IP model?

The 5-layer model associated with networks: a conceptual framework that standardizes the functions of a telecommunication or computing system into five abstraction layers.

Basically a group of networking protocols used to connect computers on the Internet.

What does the TCP do?

Provides transport functions

What does the IP do?

It provides the addressing and routing mechanism for the protocols

What is an IP address? What does it do? What are the primary functions?

It provides a device(host) identity on the network, and its primary functions are:

• Host or Network Interface Identification

• Location Addressing

What is a Subnet Mask? What does it do?

32-bit number used with an IP address that defines which portion of the address is the Network ID and which is the Host ID. They always accompanies IP address and are interrelated as each only has meaning in the context of the other.

What is a default gateway? What does it do?

The IP address of the router on the same physical segment.

• Gives remote access to other networks.

• serves as an access point or IP router that a networked computer uses to send information to a computer in another network or the internet. 

What are the 5 layers of the TCP/IP model? From uppermost to lowest:

Application, Transport, Network, Data Link, Physical

What is the application layer? What does it do?

It provides network services directly to applications and end-users. Application Layer protocols define the format and semantics of data exchanged between networked programs in the same or different devices 

It is the closest to the end-user

What are some examples of network application?

FTP (File Transport Protocol), SMTP (Simple Mail Transfer Protocol), HTTP (Hypertext Transfer Protocol)

What is the Transport layer? What does it do?

• It does host to host data transfer, and ensures end-to-end communication and data flow control between devices. I

• t is responsible for reliable and ordered delivery of data, and it includes protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). 

What is the network layer? What does it do?

• They reroute datagrams from source to destination IP

• It is concerned with logical addressing and routing. It determines the best path for data to travel from the source to the destination across different networks. 

What is the Data Link layer? What does it do?

• They transfer data between neighboring network elements

• It s responsible for the reliable transmission of data frames between devices on the same network. It also handles error detection and correction at the local network level. 

What are some examples of data link?

PPP (Point-to-Point Protocol), Ethernet

What is the Physical layer? What does it do?

The layer deals with the physical connection between devices. It defines the hardware aspects, such as cables, switches, and network interface cards. 

What is the difference between the TCP/IP model and OSI model?

OSI has 7 layers whereas TCP/IP has 5. TCP/IP is used more commonly in practice, especially in the context of the internet and modern networking

What is a Bit?

A bit is one digit, either a 1 or a 0

What is a Byte?

7 or 8 bits, depending on whether parity is used. 

For MET, always assume a byte is 8 bits.

What is an Octet?

Made up of 8 bits, is just an ordinary 8-bit binary number. 

In MET, the terms byte and octet are completely interchangeable.

What does IPv4 stand for?

Internet Protocol version v4

What is an IPv4?

The most widely used system for identifying devices on a network

How many bits is the IPv4? How is it divided?

32 bits; divided into four, 8-bit sections, called octets, separated by periods 

Within each octet is a decimal number between 0-255 (256). 4(octets) * 8(bits) = 32 bits

How many address does the IPv4 theoretically provide?

4.3 billion addresses

What the two portions of the IPv4?

Host and Network

What is a subnet?

Smaller network groups that the Internet is broken into

What does subnetting do in the internet?

Helps with network congestion.

Helps with network management.

Helps with security.

What is a Host on the internet?

a computer or other device connected to a computer network

What do hosts do on a subnet?

Each Host on a subnet has a unique IP address, and each Host on a subnet has a unique IP address

What does VLSM stand for?

Variable Length Subnet Masking

What does VLSM/Supernetting do?

Allows different network masks to be applied to the same class address space.

What can multiple network masks do? What can they permit?

• permit more efficient use of an organization’s assigned IP address space.

• permit route aggregation significantly reducing the amount of routing information at the backbone level within an organization’s routing domain.

What does CIDR stand for?

Classless Inter-Domain Routing

What is an Unnumbered IP?

A way of maximizing the use of IP addresses

What does serial interface do?

It borrows the IP address of another interface.

What is a network address? What does it do?

Also called the network number—uniquely identifies each network.

• Every machine on the same network shares that network address as part of its IP address

• In the IP address 172.16.30.56, for example, 172.16 is the network address.

What is a Host address? What does it do?

• Assigned to, and uniquely identifies, each machine on a network. 

• This part of the address must be unique because it identifies a particular machine—an individual—as opposed to a network, which is a group. 

• This number can also be referred to as a host address. 

• So in the sample IP address 172.16.30.56, the 30.56 is the host address.

What are the different address classes IP addresses are divided into?

Class A, B, C, D, E (no F)

how are the Octets used in the Class A address?

The first octet represent the network number, and the remaining three octets are the host number. Each Class A address can accommodate 127 networks with 16,777,214 hosts per network.

how are the octets used in the Class B address?

The first 2 octets represent the network number, and the remaining two octets the host number. 

Each Class B address can accommodate 16,384 networks with 65,534 hosts per network.

How are the octets used in a Class C address?

The first 3 octets represent the network number, and the remaining octet the host number. 

Each Class C address can accommodate 2,097,152 networks with 254 hosts per network.

What does IEDF stand for?

Internet Engineering Task Force

What does IANA stand for?

Internet Assigned Numbers Authority

What did the IANA do for IP addresses?

It reserved specific address ranges within class A, B, and C address space to be used in private networks.

What does APIPA stand for?

Automatic Private IP Addressing

What is a APIPA? What does it do?

It is a feature of Windows-based Operating System (OS) that enables computers to automatically assign themselves an IP address when there is no DHCP server available.

What does DHCP stand for?

Dynamic Host Configuration Protocol