The OSI Model

Routers operate at which layer of the OSI model?

• physical
• network
• transport
• data link

Bits are packaged into frames at which layer of the OSI model?

• data link
• transport
• physical
• presentation

Which are benefits of using a layered network model? 
A . it specifies how changes to one layer must be propagated through the other layers 
B . it facilitates troubleshooting 
C . it focuses on details rather than general functions of networking 
D . it breaks the complex process of networking into more manageable chunks 
E . it allows layers developed by different vendors to interoperate.

• A and B
• B, D, and E
• A and C
• All of the above

The layers of the OSI model, from the top down, are:

• application, presentation, session, transport, network, data link, physical
• session, presentation, data transport, MAC, network, physical
• physical, data link, network, transport, session, presentation, application
• presentation, application, session, network, transport, data link, physical

Which of the following operate at the presentation layer?
A . MIDI 
B . FTP 
C . SMTP 
D . TFTP  
E . JPEG

• A and B
• A, C, and E
• C and E
• A and E

Which of the following are transport layer protocols?

• TCP and UDP
• IP
• FTAM
• IP and TFTP

Which of the following are considered to be the upper layer protocols?

• presentation and session
• application and presentation
• application, presentation, and session
• application, presentation, session, and transport

Flow control takes place at which layer?

• physcial
• transport
• network
• session

Encryption takes place at which layer?

• application
• session
• presentation
• transport

True or False: The network layer uses physical addresses to route data to destination hosts.

• True
• False