BIT 3554 Exam 1

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Protocol

the language used by applications to communicate with one another · Each application needs to develop its own ________________ to be able to communicate on the network

Early Resource Sharing

- 1960s - Department of Defense for Advanced Research Projects Agency (ARPA) became interested in finding ways to share resources o Need to interconnect all computers o Allow a researcher to use the best suitable computer to perform a given task o Everything was all on one network - They are pushing for a more distributed network so that if one piece is attacked, the rest can still work. Diversify and get all eggs out of one basket. o ARPANET § ARPANET was the prototype of the internet

Overview of global internet use

- 4.66 billion people on internet - 59.5% of global population - This means about 3 billion people do not have internet connection yet - Many organizations in the government are helping to reach those who do not have internet

user interface; shared

- Each application offers a specific service with its own form of _________________, but all applications can communicate over a single, __________ network

digital; analog

- Network only carries ________________ and _____________ signals - Two broad categories of physical media are ____________ and __________

• Advantages of resource sharing

- Resource availability - Concurrency - Possible cost reduction - Possible security enhancements

ping

- Sometimes site may reject ______________ packets to avoid Denial of Service (DOS) attacks • Heavily used as a diagnostic tool

Network Interface Layer / Data Link (Layer 2)

- Specifications about ▪ network addresses - MAC address ▪ maximum packet size that a network can support ▪ protocols used to access the underlying medium ▪ and hardware addressing

Telecommunications

- _____________________ is really people using devices to communicate across long distances

Circuit switch

- _______________________ - a line is dedicated to just A and B: This is not efficient for the new network because of the amount of users

Department of Defense for Advanced Research Projects Agency (ARPA)

1960s - ___________________________________________________________________ became interested in finding ways to share resources ➢Need to interconnect all computers ➢Allow a researcher to use the best suitable computer to perform a given task

OSI vs TCP/IP Model

7 layers vs 5 layers: Presentation, Session, & Application combine to form just the 5th layer which is called Application in IP Model

public; subscribers

A ___________ network provides services to ___________________

service provider

A company that offers network service is known as a ________________________

Possible security enhancements

Advantages of resource sharing - easier to secure a machine to make it more manageable

Resource Availability

Advantages of resource sharing - more people can access information, 24/7 - now if we want to check books online, it is more available and accessible than a physical library

Concurrency

Advantages of resource sharing - multiple people can use information at the same time, or can perform as task at the same time

exchange; procedures

Application Layer (Layer 5) ➢ specifies details about ▪ the format and the meaning of messages that applications can _______________ ▪ the ____________ to be followed

all function over the same network

As an application designer you don't have to worry about creating a network or understand how the network works because they ____________________________________________

Timeline of the Internet

Check Slides or notes o Introduction of FTP and TCP/IP changed the way we were able - gives flexibility and ability to handle data - provides the base for internet o Facebook was not the first social media - MySpace and others came before it § Facebook was requiring people to verify their identity o Web 2.0 - people can post their own content, user generate a lot of content on the internet o Web 3.0 - users will be involved even more in the virtual world

physical media

Data communication Involves the transmission of information over ____________________

o Network has made telecommuting available to individuals o It has changed business communication o An entire industry emerged that develops networking technologies, products, and services

Dramatic economic shifts from computer networking

protocols

Each layer has _____________ that are particular to that layer and only interacts with items in that layer

Ping and Traceroute

Example of simple network tools

Dramatic economic shifts

Growth of computer networking has led to ____________________

Analog and Digital Signals

How do we represent info/data?

§ Internet is made up of a large amount of independently operated networks

How does the internet work?

Protocol Suites and Layering Models

Instead of creating a protocol to cover all aspects simultaneously, YOU DIVIDE THE DATA INTO _____________________________ THAT FOCUS ON INDIVIDUAL ASPECTS OF THE ENTIRE PIECE OF DATA

public/private

Internet is based on _________________ ownership on networks

the hardware/software technologies

It is possible to design network applications, without understanding ________________________________

resource sharing

Main motivation of early networks was ______________________________

packet

Network Interface Layer / Data Link (Layer 2) - Specifications about --> maximum ____________ size that a network can support

addresses - MAC address

Network Interface Layer / Data Link (Layer 2) - Specifications about --> network _______________________

medium

Network Interface Layer / Data Link (Layer 2) - Specifications about --> protocols used to access the underlying _____________

services; application software(s)

Network _______________ are provided by __________________________

Ethernet

Network interface type

dedicated circuit

Old Time - Telephone systems use a physical pair of wires between two parties to form a ________________ --> Then came packet switching - is called point-to-point connection

share

Packet Switching - Allows multiple users to ___________ a network

reach; destination

Packet Switching - Devices throughout the network each have information about how to _________ each possible _______________

packets

Packet Switching - Divides data into small blocks, called ____________

big piece; PACKETS

Packet Switching - Instead of sending data in one ____________, the data is sent in _____________ that are smaller pieces of the entire piece of data

dynamic; already established connection

Packet switching is __________ while circuit switching uses an _________________________

Two technological changes fueled a shift away from resource sharing to new applications:

Resource Sharing ➔Communication ➢Higher communication speeds enabled applications to transfer large volumes of data quickly ➢The advent of powerful, affordable, personal computers provided the computational power needed for complex computation and graphical displays

➢Communication speeds ➢New applications

Resource Sharing ➔Communication The Internet changed in two significant ways:

network-independent packet

TCP/IP defines a ________________________________

1. Network Applications and network programming 2. Data communications 3. Packet switching and networking technologies 4. Internetworking with TCP/IP 5. Additional Networking concepts and technologies

The Five Key Aspects of Networking

heterogeneity

The success of TCP/IP lies in its tolerance of _______________________

packet switching

The whole internet is based on a ______________________ technology

- A unified

There is a ____________ underlying network that supports all applications

Transport Layer (Layer 4)

This is where we talk more about TCP, this protocol helps us address many different issues we can encounter during transmission

application

Transport Layer (Layer 4) - Provides for communication from an ____________________ program on one computer to an ________________ program on another

maximum rate; congestion; correct order

Transport Layer (Layer 4) ➢Includes specifications on ▪ controlling the ________________ a receiver can accept data ▪ mechanisms to avoid network ______________ ▪ techniques to insure that all data is received in the _____________________

§ Thailand has the highest internet speed § US places 9th overall in internet speed

Want faster internet?

it would have to be too complex

We cannot have one protocol to handle all of the aspects - __________________________________________

centralized; distributed

What might be the most important motivation of creating networks? - Sharing ___________________facilities ➔Fully ________________ information systems · Connecting devices together in one location

§ Resource sharing § Searching - when you google something you are trying to get information from the network

What might be the most important of creating networks?

The Internet

What's the most revolutionary invention in the 70s-80s?

5 Layers examples

o 5 layers § Layer 1: Physical (Hardware) § Layer 2: Network Interface (Ethernet) § Layer 3: Internet (IP) § Layer 4: Transport (TCP) § Layer 5: Application (HTTP)

Application layer

Where all network protocols happen, messaging, email, all applications that we use focus on this layer, top layer closest to the user, FTP

§ Nobody controls it is distributed

Who controls the internet?

Public

__________ refers to the general availability of service, not to the data being transferred

Low-Level; physical communication medium

______________ mechanisms and technologies used to send information across a __________________________: o A wire, radio wave, or light beam

Hard Disk

_________________ evolved over time to get smaller and smaller

Networking is

__________________ is used in every aspect of business

Networking

_____________________ has changed business communication

Application

______________________ a software that provides services to a user

Networking applications

_________________________ applications depend on communication between devices

Ping; Traceroute

a) __________ - sends message that is echoed by a remote computer b) _____________ - reports path to remote computer

Does everyone in the US have internet connection?

o 90% of the population in North America have and utilize internet access o Areas that have lower internet coverage have great internet growth

private

o A _______________ network is controlled by one particular group - could be a military network

Communication protocol or network protocol

o All entities in a network must agree on how information will be represented and communicated o All communicating parties follow the same set of rules called the _______________________ or ____________________

- Network applications may include:

o Email o File transfer o Web browsing o Voice telephone calls (VoIP) o Gmail o Text messaging o Google o Social Media

Measuring internet growth

o Estimates have been based on § Analyses by automated tools which probe computer addresses stored in large online databases (DNS) § Example of simple network tools Use both Ping and Traceroute in the command prompt

The difference between network and normal application:

o Google Docs vs. Microsoft Word o Network applications require network services

TCP/IP Internet Protocol Suite (TCP/IP)

o In 1973, Vinton Cerf and Robert Kahn suggested § Stop trying to find a single best solution § _____________________________________________________

Internet facts

o In the 1970s Bob Kahn and Vint Cerf co-created the internet o Paul Baran was trying to figure out a network that would survive a nuclear attack

Internet Trends

o New technologies and new applications continue to emerge o Analog --> Digital o One of the most interesting aspects of the internet: no matter how applications chance, the underlying technology essentially remains the same

underlying technology

o One of the most interesting aspects of the internet: no matter how applications chance, the ____________________ essentially remains the same

giant

o Original computer machines were _____________ geared for big corporations and companies - really big, expensive, and heavy § This is why there was such motivation to share a network to centralize data for these ____________ machines

Packet switching benefit

o These packets go through a shared connection in the middle, they can all send items through the network connection at the same time now because of packet switching - much more efficient of using network resources

Physical layer

o _____________________ - Cables, how do we use them, only helps define the physical aspect of the network

IBM Model 350:

o ________________________ had the potential to hold to hold 3.75 Mb - this was a giant hard disk that had very little potential to hold data § Typically, the whole system would be leased from IBM for 3,200$ a month - equivalent to 30,000$/month in today's money § The _____________ hard disk alone was 750$/month

What is data communications?

o • Involves the transmission of information over physical media o • The subject draws on ideas about electric current, light, and other forms of electromagnetic radiation o • Uses mathematics and includes various forms of analysis to design and build transmission systems - Focuses on the PHYSICAL LAYER

Digital Signals

restrict use to a fixed set of values

Packet switching

revolutionized data communications

Ping

sends message that is echoed by a remote computer - sends a few testing packets to a destination you want to ping with, that machine then responds and you will receive those packets back - by doing this you can test the route, and know how fast data transmission is on this route.

Analog Signals

use all values in a continuous range

expensive

why we needed a centralized network to connect people and businesses - This technology was ________________________ to buy, rent, transport

Growth of the internet

§ The internet has grown from an early research prototype connecting a handful of sites to a global communication system § 4.66 billion internet users as of 2020 (59.5% of the world population)

ARPANET (Advanced Research Projects Agency Network)

§ ______________________ was the prototype of the internet - 1968

ISO and the OSI Seven Layer Model

• International Standardization Organization (ISO) • International Telecommunications Union (ITU)

Some examples of network applications in layer 5

▪ email exchange ▪ file transfer ▪ web browsing ▪ telephone services ▪ and video teleconferencing

Network Interface Layer / Data Link (Layer 2)

➢ Specify details about communication between higher layers of protocols (implemented in SW) and the underlying network (implemented in hardware)

radio frequencies (physical layer)

➢ Specify details about the underlying transmission medium and hardware ➢ All specifications related to electrical properties, ______________________, and signals belong in layer 1

Application Layer (Layer 5)

➢ specifies how a pair of applications interact when they communicate ➢ specifies details about ▪ the format and the meaning of messages that applications can exchange ▪ the procedures to be followed ➢ Some examples of network applications in layer 5 ▪ email exchange ▪ file transfer ▪ web browsing ▪ telephone services ▪ and video teleconferencing

Packet switching changed networking in a fundamental way:

➢Allows multiple users to share a network ➢Divides data into small blocks, called packets ➢Devices throughout the network each have information about how to reach each possible destination

Internet Layer (Layer 3)

➢Layer 3 protocols specify communication across the Internet - This is where IP is defined at, Internet Protocol (IP)

Ping summary

➢Number of packets sent and received ➢Packet loss ➢Min/mean/max round trip times

• Transport Layer (Layer 4)

➢Provides for communication from an application program on one computer to an application program on another ➢Includes specifications on ▪ controlling the maximum rate a receiver can accept data ▪ mechanisms to avoid network congestion ▪ techniques to insure that all data is received in the correct order


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