Routers operate at which layer of the OSI model?

• physical

• transport

• network

• MAC sublayer of the data link layer

• session

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

• data link

• transport

• physical

• presentation

• application

Which of the following 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 only

• B, D, and E

• A and C only

• none of the above

• 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

• application, encryption, network, transport, logical link control, 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

• none of the above

Which of the following are transport layer protocols?

• TCP and UDP

• IP

• FTAM

• IP and TFTP

• 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

• application

Flow control takes place at which layer?

• physical

• transport

• network

• MAC sublayer of the data link layer

• session

Encryption takes place at which layer?

• application

• presentation

• session

• transport

• data link

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

• True

• False