6. When connecting devices in a network, you need a switch. When do you need a router? 7. What is encapsulation and de-encapsulation? How is it used in a network? 8. Assume that the number of users of the Internet at the beginning of 2015 (January 1) is 250 Million. If the growth of users increases 15% per year, how many users will be using the Internet at the beginning of 2021 (January 1) 9. In the TCP/IP protocol suite, the Network layer is primarily responsible for what tasks? Name the main protocols that function at the Network layer. 10. Assume we need to download text documents at the rate of 500 pages per second (each page is 24 lines with 80 characters per line 8 bits per character)). What is the required bit rate of the channel