Willow's new branch office has the following TCP/IP network setup as shown in Figure 2. The IP addresses of the devices are listed in Table 1. Laptop 1 Smartphone 1-3 Laptop 2 Laptop 3 Access Point LAN 1 Printer A ISP ADSL Modem Tablet 1 Tablet 2 Tablet 3 Firewall Laptop 4 Ethernet Switch Workstation A Workstation B Workstation C Workstation D Device ADSL Modem File Server Database Server Printer A Printer B Workstation A-D Smartphone 1-3 Tablet 1-3 Laptop 1-4 Laptop 1-4 Figure 2 Printer III LAN 2 Database Server Cloud IP Address Public: 20.212.210.16 Private: 192.168.1.1 192.168.7.122 192.168.7.192 192.168.4.111 192.168.7.222 Dynamic: 192.168.7.101 - 192.168.7.200 Dynamic: 192.168.4.201 - 192.168.4.238 (LAN 1) Dynamic: 192.168.7.201 - 192.168.7.238 (LAN 2) Table 1 (a) Describe the functions of the ADSL Modem, Firewall, and Switch (as shown in Figure 2). (b) Smartphones and Tablets can get the network from the Access Point without using cables. Name the technology involved and describe the transmission medium using in LAN 1. (c) Servers and Workstations connect their networks through the Ethernet Switch. Explain which network topology is used and describe the transmission medium using in LAN 2. (d) Which Class does the IP address of the File Server belong to? (e) What is the appropriate subnet mask for all devices with IP address 192.168.1.X, 192.168.4.X or 192.168.7.X to use both printers (LAN 1 and LAN 2) at the same time? Justify your choice. (f) Calculate the number of usable hosts per subnet with the subnet mask in part (e), clearly showing your steps.