network models

Question 1

application layer

Answer 1

purpose: (5th layer)
User’s access to network, software to perform work
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examples:
HTTP, SMTP, DNS, FTP, DHCP, IMAP, 
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PDU: Data

Question 2

transport layer

Answer 2

purpose: (4th layer)
End-to-End Management1.Link application layer to network2.Segmenting and tracking3.Flow control
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exampes:
TCP, UDP
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PDU: segment

Question 3

network layer

Answer 3

purpose: (3rd layer) 
Deciding where the message goes (1) Addressing (2) Routing
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examples: IP, ICMP
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PDU: Packet

Question 4

data link layer

Answer 4

purpose: (2nd layer)
Move a message from one device to the next1.Controls hardware2.Formats the message3.Error checking
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examples: Etherner
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PDU: Frame

Question 5

physical layer

Answer 5

purpose: (1st layer)
Transmits the message
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example: 
100BASE-T, 802.11n
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PDU: none