Computer Networking Chapter 1:

Four processes that are used when a user attempts to access a network (steps of network communication) client side

1. The NIC card on the server receives signals from the network medium and converts them into message data, which is read by the NIC driver. 2. The NIC driver passes the message to the network protocol. 3. The network protocol determines which server software the message is targeting and passes the message to this designated software. Remember that a computer can have many clients and many servers running at the same time. For example, a computer running Windows Server 2012 might be acting as a mail server and a file server. Each server function requires different server software. 4. The server software receives the message and responds by sending the requested data to the client computer, using the four steps outlined previously.

Main tasks a CPU is responsible for

1. executes instructions from computer programs (instructions come from inputs of course) 2. runs instructions making up the OS (making apps run)

How many addresses are in the TCP/IP protocol?

1. logical address (IP address) 2. physical address (Media Access Control {MAC} address)

Obvious types of computer networks

1. network servers 2. workstations that run operating systems (Windows, Linux, UNIX, Mac)

Two types of network models

1. peer-to-peer 2. server based (client/server)

32 bit version of an operation can only access how much RAM?

4gb 64 bit operating systems has access to thousands of gigs of RAM

Example of bits

5 volts of electricity = 1 bit, and a pulse of 0 volts can represent a 0 bit. Can also be pulses of light as well (1 = light, 0 = absence of light) = optic cables

What's an internetwork?

A collection of LANs tied together by devices such as routers. (Multiple LANs)

Domain

A collection of users and computers whose accounts are managed by Windows servers (called domain controllers)

What is a "bus"

A collection of wires carrying data from one place to another on the computer

What's a ping command?

A command that sends a message from one computer to another, asking the other computer whether it's listening on the network If a computer receives a ping = it replies so that the sending computer knows the message was received (like a cell phone call, ping = "can you hear me now")

Computer Network

A computer network consists of two or more computers connected by some kind of transmission medium, such as a cable or air waves.

server-based network

A network in which resources security and administration and other functions are provided by dedicated servers. Windows Server, Redhat Linux, and Unix

Frame

A packet with the source and destination MAC address added to it (a letter that's been addressed and stamped and is ready to deliver) Frames = final state of data before it's placed on the network medium as bits

LAN

A small network, limited to a single collection of machines and connected by one or more interconnecting devices in a small geographic area Local Area Network

Client (networking

A workstation running a client OS (Windows 10) or the network software on a computer that requests network resources from a server physical computer = client computer

Advantages/Disadvantages of peer to peer networks

Advantages 1. Cheapest and easiest to install for small organizations (only requires a client OS on desktop computers) 2. Most suitable for small operations or tight budgets 3. Easy to use and don't require extensive staff training Disadvantages 1. No centralized control = difficult to manage security

BIOS

BIOS = basic input/output system Set of instructions located in a chip on the motherboard

Why isn't a disk drive optimal for working memory?

Because RAM is thousands of times faster than the fastest disk drives (nanoseconds for RAM with transferring information, while Disk Drive is milliseconds).

Why is RAM called volatile memory?

Because it requires continuous power to work (no moving parts, any info the CPU processes should be in RAM)

Why is the internet a public network?

Because it uses devices like routers and Web servers that make up much of the network (directly through an IP address)

How is data on a computer stored and processed as?

Binary digits (A bit holds a 1 or 0 value)

Identify each motherboard component on the back

Blank

CPU Socket

CPU is installed in this socket

SSD

Called flash memory (no moving parts), long term storage that has faster access times that mechanical hard drives phones and laptops especially

Packet

Chunk of data sent across a network data is sent through "packets" (Packet = an envelope with the zip code but not the street address) Zip Code = IP address only

3 parts of a client

Client OS = OS designed to access network resources Client computer = run user applications and access network resources Client Software = the software that requests network resources from server software on another computer

What's a CMOS?

Complementary metal oxide semiconductor It's used to hold information (for the CPU) for an OS to boot, status of hardware devices, and even a system password It's nonvalatile memory since it doesn't require power to store information

Protocols

Defines the rules and formats a computer must use when sending information across a network Security defense for clients that want to send information over the network

If you want networking fundamentals, start on card 67

FUUUUUU

True or False, maintaining and upkeeping a computer network is easy

False, it's difficult (considerable know-how is required, even for the smallest networks)

What are examples of inputs in Microsoft Excel

Formulas and Equations. These formulas will give instructions (input) for the CPU to calculate numbers (Program and Spreadsheet file = input for the cpu)

Processor on a graphics card =

GPU (graphics processing unit) If the output of a GPU is to draw a circle, then the GPU will perform calculations that will draw that circle

Fundamentals of network communication

Here we go

When computers transfer network across a network, how is the frequency of that information transferred?

In short burst (1500 bytes) Each burst of data = has MAC and IP addresses of both the source and destination computers

Main distinction between intranet and internet

Intranet is a private network (school or company network) in which devices and servers are available only to users connected to the internal network

MAN

Metropolitan Area Network; a geographic network that covers a larger geographic area such as a city or community; may be used to connect computers in libraries, government agencies, etc. together - no more than 30 miles in size

Few examples of output components

Monitors and Printers (couls also include storage devices, network cards, and speakers) A disk drive connected to a USB port allows reading files from the disk (input) and writing files to the disk (output)

Output of a computer

Most common = monitor (The CPU sends instructions to the graphics card to display the letter A, which is then sent to the computer monitor.)

Equate the motherboard to a human body part

Motherboard = Nerve Center of a computer A motherboard = A network (of wires) that connects all computer components to the PC.

Which PC component can perform all three functions?

Network cards

Are all inputs registered manually by the user on a PC?

No when you boot your computer, the computer may start programs without any obvious action from you to initiating it. While it may not seem obvious, computers don't actually do anything without first getting input to jolt them into action.

Stand-alone components (computer hardware)

Old-fashioned computers without any networking components (runs word and spreadsheet, but no web browsers and email) (needed NIC, network medium, and interconnecting device)

Explain in detail how a network card can perform all three functions?

Output = when data is sent from the computer to the network Input = when data comes from the network to the computer Processing = many network cards have rudimentary processors that performs actions (helps to supplement the main CPU in a computer)

PCI E (express) expansion slot

PCI-Express supersedes PCI and supports faster data transfer speeds. The larger slots are suitable for high-performance expansion cards, such as graphics cards and disk controllers. The smaller slots are best suited to sound cards and network interface cards. Tomsho, Greg. Guide to Networking Essentials (p. 7). Cengage Learning. Kindle Edition.

Encapsulation

Process of adding IP addresses and then MAC addresses to chunks of data info added in front = header....... info added at the end = trailer

Short-term storage refers to which hardware component?

RAM

Network clients

Requests information that's stored on another computer or device (allows a computer to share its resources by fielding requests generated by network clients) Web browser = sends a request for a web page to a web server

Primary motivation of networking

Sharing information with multiple people (internet, web browsers, email programs) Sharing information, accessing the web, communicating with other people (all)

Two categories of storage

Short-term and long-term storage

RAM Slots

Slots for installing RAM on the motherboard

Example of how working storage works (Excel Spreadsheet)

So to run a spreadsheet program, there must be enough RAM to load both the spreadsheet program and the data in the spreadsheet. If there's not enough available memory, the spreadsheet program won't run, or the computer uses the disk drive to supplement RAM temporarily.

Long term storage

Storage that gets maintained even when there's no power (hard disks, CD/DVD's, and USB falsh drives) Used to store document and multimedia files as well as the files that make up applications and the OS

The most common network protocol

TCP/IP

What's the role of the BIOS?

Tell the CPU to perform tasks when power is first applied to the computer, including 1. initializing motherboard hardware 2. performing a power-on self-test (POST) 3. and beginning the boot procedure

What PC component is responsible for processing?

The CPU (it determines what letter was typed (from the input) by looking up the keyboard code in a table

Access time

The average amount of time between the request to read or write data and the time the action is performed

Rotational delay .... or "latency"

The average amount of time platters take to spin into position

Most important bus I need to remember

The bus connecting expansion slots to the motherboard. You connect a network interface card (NIC) into one of these slots

Chipset with heat sinks

The chipset consists of two chips referred to as the Northbridge and the Southbridge. These chips control data transfers between memory, expansion slots, I/O devices, and the CPU. The heat sink sits on top of the chipset to prevent it from overheating.

What is the largest internetwork in the world?

The internet. When you go online to browse the Web (household LAN network), it becomes part of the internetwork (Millions of WANs)

What's an extranet?

The middle ground that sits between internet and intranet (limited and controlled access to internal network resources). Used with two organizations.

What are platters on a hard drive?

The platters are the magnetic disk that store data in the form of magnetic pulses. Because it's long term storage, magnetic pulses are maintained even when power is turned off

Credentials

The username and password for accessing a computer

Main power connector

This connector is where the motherboard receives power from the system power supply. Tomsho, Greg. Guide to Networking Essentials (p. 7). Cengage Learning. Kindle Edition.

What is the input of a computer

This is information that's input to a computer from a device Examples = keyboard, storage device

True or False? The Internet can be classified as an internetwork and a (very large) WAN

True

IDE connector

Used for connecting Integrated Drive Electronics (IDE) hard drives and CD/DVD-ROM drives. Most systems now use SATA for hard drives and IDE for CD/DVD-ROM drives. Tomsho, Greg. Guide to Networking Essentials (p. 7). Cengage Learning. Kindle Edition.

SATA connectors

Used for connecting hard drives and CD/DVD drives that use the Serial AT Attachment (SATA) specification.

PCI bus expansion slots

Used to add functionality to a PC by adding expansion cards that have a Peripheral Component Interconnect (PCI) connector. Tomsho, Greg. Guide to Networking Essentials (p. 7). Cengage Learning. Kindle Edition.

Where are computer networks found?

Virtually everywhere in every business, school, and home (If you have a network and a computer, you have a computer network)

Compare a TCP/IP protocol with a UPS mailing service

When a letter is mailed in the US, it requires a street address and a zip code (zip code = correct region of the country, and the street address = correct home or business) IP address = get the message to the correct network MAC address = get the message to the right computer on the network

What's a WANs?

Wide area networks = spans distances measured in miles and links separate LANS (uses third-party communication such as phone companies to carry network traffic)

Internet

Worldwide public internetwork that uses standard protocols such as TCP/IP, DNS, HTTP, and others to transfer/view information

Third Section: Networking Terminology

Yay!

Can a LAN be wireless?

Yes, commonly found in a household. You have a single wireless access point (such as a router) interconnecting every device in the house (PC, Laptop, Tablet)

Multicore CPU

a CPU containing two or more processing cores. (like a person with two brains)

Network model

a model of memory that views it as an organized system of linked information

Actuator arm (hard drive)

a response to commands from the computer to read or write a file (read = input, write = output) Faster the hard drive = better

Server based networks

allow centralized control over network resources, mainly by providing an environment in which users log on to the network with a single set of credentials maintained by one or more servers running a server OS.

In general, more storage = _____ performance

better

A collection of 8 bits is called a

byte 1 byte of MP3 = 1/17 thousandth of a second of music

The heart of a computer network is the ________

computer (acts as a facility of communication)

peer-to-peer network

computers function as clients or servers (computer sharing a printer it's connected to and acting as a client by accessing a file shared by another computer) No centralized control over who has the network (each user maintains their own shared resources) Every user must act as the administrator of his or her computer's resources

CPU's are usually composed of two or more processors called ____

cores

A faster computer requires a ______ bus

faster bus

Before a computer can do any processing, it requires ___

input

The keyboard and mouse perform which functions?

input

The hard drive performs which function?

input (when files are read from the drive) and output (when files are written to the drive)

List of input devices

keyboards microphones Webcams scanners External interfaces, such as serial, FireWire, and USB ports, can also be used to get input from external devices. CDs and DVD's (they store programs and data files containing coputer instructions and data)

Each step of a client accessing network resources is referred to as a

layer All layers have a specific function to accomplish and all of the layers work together

Multicore processors carry out multiple instructions _____

multicore CPUs enable computers to carry out multiple instructions simultaneously, which results in better overall performance when running demanding applications.

Input/Output devices (graphics cards) typically have

onboard processors (ancillary processors)

RAM

random access memory (When a computer is turned off, the memory on RAM is gone). When power is restored, RAM has no data stored until the CPU begins to write data to it. Known has (working storage) = Everything the CPU is processing must be available in RAM

NIC driver

receives data from protocols and then forward this data to the physical NIC, which transmits data onto the medium

Not so obvious types of networks

routers and switches (these move data fro computer to computer and network to network)

Server

short, a computer becomes a server when software is installed on it that provides a network service to client computers.

Why is data transferred in bursts across a network?

• The pause between bursts might be necessary to allow other computers to transfer data during pauses. • The pause allows the receiving computer to process received data, such as writing it to disk. • The pause allows the receiving computer to receive data from other computers at the same time. • The pause gives the sending computer an opportunity to receive data from other computers and perform other processing tasks. • If an error occurs during transmission of a large file, only the chunks of data involved in the error have to be sent again, not the entire file.

Student Computer Recommendations

• Use of virtual machines recommended • Windows 10 Enterprise or Education Edition • Computer name: Net-XX (replacing XX with a student number, such as 01, 02, and so forth) • Administrator account: NetAdmin with the password Password01 set to never expire • Workgroup name: NetEss • Memory: 1 GB required, 2 GB or more recommended • Hard disk 1: 60 GB or more (Windows installed on this drive); a second NTFS-formatted partition assigned drive letter D is preferable but not required. • Hard disk 2: Unallocated 60 GB or more • IP address via DHCP server or static if required on your network • Wireshark installed (a free protocol analyzer from www.wireshark.org) • Internet access

Let's say that you need to add four numbers (1+2+3+4), how many processes would be needed in order to add these numbers? Now compare the difference with a person with one brain and a person with two brains completing this task of summing all these numbers

(1+2+3+4) would require 3 processes. 1+2, 3+3, and 6+4. With one brain, you'd do each task seperately. However, with two brains, you can do two tasks at the same time (1+2 and 3+3 at the same time). Therefore multicore is faster

Five step process for a computer sending a ping

1. A user at Computer A types ping 10.1.1.2 (the IP address of ComputerB) at a command prompt. 2. The network software creates a ping message. 3. The network protocol packages the message by adding IP addresses of the sending and destination computers and acquires the destination computer's MAC address. 4. The network interface software adds MAC addresses of the sending and destination computers and sends the message to the network medium as bits. 5. Computer B receives the message, verifies that the addresses are correct, and then sends a reply to Computer A, using Steps 2 through 4.

Four processes that are used when a user attempts to access a network (steps of network communication) User Side

1. An application tries to access a network resource by attempting to send a message to it. 2. Network client software detects the attempt to access the network. Client software formats the message generated by the application and passes the message on to the network protocol. 3. The protocol packages the message in a format suitable for the network and sends it to the NIC driver. 4. The NIC driver sends the data in the request to the NIC card, which converts it into the necessary signals to be transmitted across the network medium.

Chapter 1: 4 Goals I'll achieve after reading this chapter

1. Describe basic computer components and operations 2. Explain fundamentals of network communication 3. Understanding networking terminology 4. Comparing different types of network models

Three basic tasks all computers perform

1. Input 2. Processing 3. Output

Four major PC Components

1. Motherboard 2. Hard Drive 3. RAM 4. Bios/CMOS

Three types of network software

1. Network clients and servers - (OS, software, and others for connecting multiple computers to one another) 2. Protocols - (rules and formats a computer must use when sending information across the network) 3. NIC driver (driver = software instruction for the hardware, which would be the network interface card) Client = a desktop computer or workstation that is capable of obtaining information and applications from a server.

Computer boot procedure

1. Power is applied to motherboard 2. CPU starts 3. CPU carries out the BIOS startup routines (including POST) 4. Boot devices, (in BIOS), are searched for an OS 5. OS loaded into RAM 6. OS services are started

RAM fundamentals

1. RAM consists of capacitors to store data and transistors to control access to data 2. Capacitors = require power to maintain the bits they store

3 types of server components

1. Server Operating System - OS installed on a computer is designed to mainly share network resources 2. Server Computer = Give client computers access to network resources and services 3. Server Software = Software that responds to requests for network resources