Network Fundamentals + Lans|Week 1 lecture + readings (chapter 1 all and chapter 7.1, 7.2, 7.3) Flashcards
What does the OSI Model stand for? Eg, the O___ ___ ___ ___ model is shortened to ‘the OSI’ model.
Open Systems Interconnection Reference
The OSI model was developed in what year?
1984
Who (the ____ _____ ____) created the OSI model?
The International Organization for Standardization
The ISO made the OSI. True or false?
True
How many layers does the internet model have?
5
how many layers does the OSI model have?
7
What layer defines the rules governing the transmission of data bits, such as voltages of electricity, number of bits per second, and the physical format of cables and connectors used?
Layer 1: The Physical Layer
What layer marks where a message starts and where it ends?
Layer 2: The Data Link Layer
Layer 2, the data-link layer, performs error detection and correction. True or false?
True
The network layer, layer 3, performs routing. True or False?
True
The transport layer, layer 4, determines the next computer to which the message should be sent, so the message can follow the best route through the network, and finds the full address for that computer if needed. True or False?
False, the transport layer is involved with end-to-end.
The transport layer, layer 4, deals with end-to-end issues, such as entering and departing the network. True or false?
True
Which two layers perform error checking? Type: Layer __ and layer ___
Layer 2 and layer 4
Which layer fragments packets if needed?
Layer 4, transport layer
What are the 7 layers of the OSI model?
Physical, Data Link, Network, Transport, Session, Presentation, Application
What is layer 5 in the OSI model?
Session Layer
What is layer 6 in the OSI model
The presentation layer
what is layer 7 in the OSI model
The application layer
Which layers of the OSI model does the internet model collapse/condense together?
the top three layers
cables and satellites are examples of what?
media
computers, modems and switches are examples of what
hardware devices
The application layer in the internet model is perfectly the same as the application layer in the OSI model. True or false?
false, the application layer in the internet model includes layer 5 (session), 6 (presentation) and 7 (application) of the OSI model.
The application layer in the internet model includes the application, presentation and session layers of the OSI model. True or false?
True
What do people call the group containing the data-link layer and the physical layer?
Hardware layers
When people group the transport and network layers, what do they call that?
internetwork layers
what are the three groups of layers
hardware, internetwork, and application
what protocol is used for Web applications?
HTTP
what does HTTP stand for
Hypertext Transfer Protocol
Some expects use the word ‘packet’ to mean what?
Protocol Data Unit
All layers except the physical layer create a new PDU as the message passes through them. What does PDU stand for?
Protocol Data Unit
what does TCP stand for?
Transmission Control Protocol
what does UDP stand for?
User Datagram Protocol
What is the term which describes how the PDU at a higher level is placed inside the PDU at the lower level so that the lower level PDU wraps around the higher ones?
encapsulation
An advantage of layers is that using different software and protcols is that PDUs add to the total amount of data that must be sent and that the different software packages increases the computing power needed in computers. True or false?
false, its a disadvantage
The set of software used to understand the different protocols is called a protocol what?
stack
An advantage of using layers is that it makes it easier to develop web applications as the software does not need to perform error checking or routing as those are performed by the data link and network layers. True or false?
true
For communication to be successful, each layer in one computer must be able to communicate with its matching layer in the other computer. What ensures that the software used at the different layers is the same?
Standards
Standards define what which explain how hardware and software that conform to the standard are required to operate?
protocols
What is a de facto standard?
A de facto standard is one that emerges in the marketplace and are supported by several vendors, but have no official standing.
An example of a de facto standard is _____.
Microsoft Windows, or any other program or hardware used commonly in the industry but doesn’t have an official standard saying that it must be used.
A __ ____ standard is developed by an official industry or government body.
de jure
A de jure standard is also known as a ____ standard. These are developed by governments or official bodies.
formal
the International Organisation for Standardization makes technical recommendations about data communication interfaces. They are known as the ISO. True or false.
True
The Physical Layer (layer 1) uses the following standards: HTTP, HTML, MPEG, H.323, SMTP, IMAP, and POP. True or false?
False, those are all application layer protocols. (Layer 7 OSI, layer 5 internet)
The Transport layer uses ____ and ____
TCP and UDP
The network layer uses ____
IP