1.2 Understanding the OSI Model

Question 1

With windowing, the client adjusts ________________ amount of data sent in each segment as the number of retransmissions occur, and adjust to a ________________ amount of data sent in each segment as the number of retransmissions are eliminated.

Answer 1

lower

higher

Question 2

_______________ allows us to take a big chunk of data and cut it up into smaller packets and send them all out in different directions. It allows the recipient to put the packet back together, and since it is sequenced can be put back together in order.

Answer 2

Packet reordering

Question 3

You should think of a _________________ as a conversation that must be kept separate from others to prevent intermingling of the data.

Answer 3

session

Question 4

In Packet Switching the data may take different paths from the client to the host during a session, in ______________ the data takes the same path from the client to the host during that session.

Answer 4

Circuit Switching

Question 5

_________________ includes transfer of data across the network, reestablisment of a disconnected session, and acknoledgment of data received.

Answer 5

Maintaining a Session

Question 6

What does OSI stand for?

Answer 6

Open Systems Interconnection Reference Model

Question 7

The OSI serves as the ______________ model for a network.

Answer 7

reference

Question 8

_________________ is used in Layer 6 to scramble the data in transit to keep it secure from prying eyes, and provide confidentiality of data.

Answer 8

Encryption

Question 9

Most networks use ______________ switching because we have other methods to check if it is being sent to the other in, if not it will try other paths until the data gets there.

Answer 9

Packet

Question 10

Layer 2 devices vew networks ______________.

Answer 10

logically

Question 11

Layer 4 is for segments almost exclusively, but if your using UDP you are using a ________________.

Answer 11

datagram

Question 12

Switches, the physical devices, are layer ______________ devices.

Answer 12

2

Question 13

At the _________________ layer of the OSI model we are dealing with the IP addresses, any routing decisions being made here.

Answer 13

Layer 3 - Network

Question 14

_________________ is where applications send out announcements to other devices on the network to state the services they offer. This can also be done by Active Directory if using it.

Answer 14

Service Advertisement

Question 15

H.323 and H.264 are both used to Setup, maintain and tear-down _________________connections such as Skype or Facetime.

Answer 15

video

Question 16

Another ICMP used is called _______________ which traces a route that a packet takes through the network and tell you every router along the way it goes through.

Answer 16

traceroute

Question 17

________________ is the data type in the transport layer.

Answer 17

Segment

Question 18

In layers 5, 6, and 7 data is called ______________.

Answer 18

data

Question 19

ASCII, EBCDIC, and UNICODE all tell us how to get _________________ out of 1’s and 0’s.

Answer 19

text

Question 20

There aren’t really Layer 5 _________________, mostly just protocols.

Answer 20

devices

Question 21

_________________ involves checking of user credentials and assigning numbers to sessions to help identify them, which allows to negotiate service needed for that session and determine who begins sending data.

Answer 21

Setting up a Session

Question 22

The SYN/SYN-ACK/ACK messaging of TCP is called the ________________.

Answer 22

Three-way handshake

Question 23

The big question being answered at layer 3 is how data should be ______________ or ______________.

Answer 23

forwarded or routed

Question 24

H.323 and H.264 both operate over the _________________ protocol.

Answer 24

RTP (Real-Time Protocol)

Question 25

What are the 7 layers of the OSI model?

Answer 25

7. Application 6. Presentation 5. Session 4. Transport 3. Network 2. Data Link 1. Physical

Question 26

________________ allows the clients to adjust the amount of data sent in each segment and continually adjusts to send more or less data per segment transmitted.

Answer 26

WIndowing

Question 27

_________________ is basically text, and 8 bit code that tells you what letter the code represents.

Answer 27

ASCII

Question 28

The _________________ layer of the OSI model involves the signaling, cabling, connectors. (Cable, NIC, Hub)

Answer 28

Layer 1 - Physical

Question 29

The Internet Protocol comes in two versions ______________ and ______________.

Answer 29

IPv4 and IPv6

Question 30

Hubs, WAPs and Media Converters work at layer ______________ of the OSI model.

Answer 30

Physical Layer (Layer 1) (Dumb Devices)

Question 31

NIC's, Bridges, Swiches, and Mac Addresses are all Layer ______________ devices.

Answer 31

Layer 2 (Data Link)

Question 32

At the _________________ layer of the OSI model handles a lot of the communication that will be encrypted and decrypted.

Answer 32

Layer 6 - Presentation

Question 33

Our networks today work under the ______________ model.

Answer 33

TCP/IP

Question 34

At the _________________ layer of the OSI model we find the control protocols, and tunneling protocols.

Answer 34

Layer 5 - Session

Question 35

________________ is kind of like certified mail, you get proof that the data is delivered in full.

Answer 35

TCP

Question 36

The _________________ layer, Layer _________________, provides application-level services and is where the users communicate with the computer.

Answer 36

Application Layer (Layer 7)

Question 37

______________ is needed to prevent the sender from sending data faster than the recipient can accept it.

Answer 37

Flow control

Question 38

Route discovery and selection is manually configured as a static route or dynamically through a ______________, which help decide which path data will take.

Answer 38

routing protocol

Question 39

Numerous routed protocols were used for logical addressing over the years but only the ______________ remains dominant.

Answer 39

Internet Protocol (IP)

Question 40

GIF, JPG, TIF SVG, and PNG all tell us how to get _________________ out of 1's and 0's.

Answer 40

graphics

Question 41

At the _________________ layer of the OSI model shows what we see when using the application.

Answer 41

Layer 7 - Application

Question 42

The ______________ layer packages data into frames and transmits those frames on the network, performing error detection/correction, uniquely identifying network devices with an address (MAC), and providing flow control.

Answer 42

Data Link Layer (Layer 2)

Question 43

A ________________ works like a regular layer 2 switch and a layer 3 router combined.

Answer 43

multilayer switch

Question 44

Layer 3 of the OSI model is all about ______________, and is known as the ________________ layer.

Answer 44

Routing | Network Layer

Question 45

In layer 3 data is called ______________.

Answer 45

packets

Question 46

_________________ and _________________ are level 6 encryptions algorithyms that takes the 1's and 0's and scrambles them up so noone else can read them.

Answer 46

TLS | SSL

Question 47

Packet Switching is known as ______________, where data is divided into packets and forwarded.

Answer 47

routing

Question 48

_________________ such as HTML, XML, PHP, and JavaScript are all Layer 6 (Presentation), because they tell ASCII how to display the text.

Answer 48

Scripting Languages

Question 49

________________ is really good for audio and visual streaming because you send a lot of data, and there is a lot less overhead vs using TCP. You won't notice dropped packets with streaming in UDP.

Answer 49

UDP

Question 50

_________________ unite communicating components from more than one network application.

Answer 50

Application Services

Question 51

Layer 7 email does not deal with applications like Outlook, but the _________________ applications of email such as POP3, IMAP, and SMTP.

Answer 51

lower-level

Question 52

Do Some People Fear Birthdays

Answer 52

``` data - 7,6,5 segments - 4 packets - 3 frames -2 bits - 1 ```

Question 53

In layer 1 data is called ______________.

Answer 53

bits

Question 54

POP3, IMAP, SMTP, HTTP, HTTPS, DNS, FTP, FTPS, Telnet, SSH, and SNMP are all application services used in Layer _________________.

Answer 54

Layer 7, Application Layer

Question 55

Within the IP communication is the _________________ layer of the OSI model, we find the TCP/UDP protocols here.

Answer 55

Layer 4 - Transport

Question 56

Layer 5 is the _________________ layer.

Answer 56

Session Layer

Question 57

The most common protocols used in Layer 3 are ________________, ______________, and _____________.

Answer 57

IPv4 protocol IPv6 protocol Internet Control Message Protocol (ICMP)

Question 58

IPv4 and IPv6 are both Layer ______________ protocols.

Answer 58

3

Question 59

If a TCP segment is dropped, the protocol will ask for acknowledgment each and every time data is sent. If it does not get the acknowledgment it will resend the data. That's why we call it a ________________ protocol.

Answer 59

connection full protocol

Question 60

_________________ is done by the computer to have compatability between different devices.

Answer 60

Data formatting

Question 61

With a ______________ routing protocol, all of the routers continually talk to each other to decide the best way for data to be routed from client to host.

Answer 61

dynamic

Question 62

The _______________ protocol is used to send error messages and operational information about an IP desitnation.

Answer 62

ICMP (Internet Control Message Protocol)

Question 63

TCP, UDP, WAN accelerators, Load Balancers, and Firewalls are all of examples of Layer _________________ protcols and devices.

Answer 63

Layer 4 Transport

Question 64

_________________ is ending of a session due to mutual agreement (after the transfer is done) or when the other party disconnects.

Answer 64

Tearing Down a Session

Question 65

______________ involves taking some limited amount of resource and using it more efficiently. Allows multiple users to use a baseband connection at the same time.

Answer 65

multiplexing

Question 66

The two main protocols of the Layer 4 Tranport Layer, are ________________ and ________________.

Answer 66

TCP (Transmission Control Protocol) | UDP (User Datagram Protocol)

Question 67

The ________________ is the dividing line between the upper and lower layers of the OSI model.

Answer 67

Transport Layer (Layer 4)

Question 68

_________________ occurs when devices, such as routers, allocate memory to store segments if bandwidth isn't readily available.

Answer 68

Buffering

Question 69

In ______________ data is divided into messages, similar to packet switching, except these messages may be stored then forwarded more like an email.

Answer 69

Message Switching

Question 70

Layer 3 switching is called ______________.

Answer 70

routing

Question 71

In layer 2 data is called ______________.

Answer 71

frames

Question 72

In layer 4 data is called ______________.

Answer 72

segments

Question 73

The _________________ layer, Layer _________________, is responsible for formatting the data exchanged and securing that data with the proper encryption.

Answer 73

Presentation Layer (Layer 6)

Question 74

_________________ is used by computers to share files over a network, and by WIndows to share files on the inside.

Answer 74

NetBIOS

Question 75

When you think of Layer 6 you should think about _________________ and _________________.

Answer 75

data formatting | data encryption

Question 76

MP4, MPG, and MOV all tell us how to get _________________ out of 1's and 0's.

Answer 76

video

Question 77

______________ is called different names as it flows though different layers of the OSI model.

Answer 77

data

Question 78

_________________ provides encryption between your computer and websites, such as HTTPS.

Answer 78

TLS (Transport Layer Security)

Question 79

In the _________________ layer of the OSI model we might find MAC addresses in the frame of communication, all of the switching decisions occur here.

Answer 79

Layer 2 - Data Link

Question 80

Their is no sequencing, or aknowlegement with the ________________ protocol.

Answer 80

UDP

Question 81

The most common examples of Layer 3 devices are ___________________ and _______________

Answer 81

Routers | Multilayer Switches

Question 82

The most common ICMP used is called _______________, which sends out a single packet to a test to an IP address and tells you if it was received or not and how long it took.

Answer 82

ping

Question 83

With TCP, the client sends a ________________ message asking if the server is ready for data, the server sends back a ________________ message saying it is ready to receive data, then the client sends a ________________ message notifiying that data is on the way.

Answer 83

SYN (synchronization) SYN-ACK (synchronization acknowledgment) ACK (acknowledgment)