1. What are the typical causes of packetloss in a packetswitched network? 2- An applicationlayer protocol typically defines fourthings. What are these four things? 3. List three command used by FTP over control connection and explain it. 4- What is the difference between network applications andapplication layer protocols? 5. Both HTTP and FTP can be used for downloading and uploading files. Give one similarity and one difference betweenthe two protocols. 6- What is the purpose of the IF- MODIFIED-SINCE field in an HTTP GETmessage