2. Describe ASK, explain how it works and why we use it:
 Â
3. Explain what PCM does and how it works:
 Â
4. Which of the following networking device(s) block(s)broadcast traffic, thus dividing networks into separate subnets?(Hint: only OSI Network layer devices can divide networks intoseparate subnets): Routers, Switches, Wireless Access Points(bridges)
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5. List the three types of multiplexing from the text andexplain how they work:
. List two network layer protocols and explain what they do:
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6. Explain what the acronym “ARQ†stands for and explain how itworks:
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7. The Session and Presentation layers are explicit layers inthe OSI model, but are embedded within the Application layer of theTCP/IP protocol stack. Explain what the Session and Presentationlayers do.
Session: Â Â Â
Presentation: Â Â Â
8. How does the application layer handle security?
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