Question One (1omks) a)Explair the following terms as use I in networking (4 ma (ks) i) Multiplexing ii) Switching b)Unguided transmission transmits the elect romagnetic waves without using any physical medium Explain three such tra nsmissi on (6 mar ks) c) Consider the following address an I subnet mask: Address:192108.1.10 Subnet Mask :255.255.255.0 Calculate the network address (4 marks) d) Briefly describe a default gateway (2marks) Question Two (15mks) a) Explain the three basic elements of layered network architecture (6 marks) b)Transmi ssior mode is defined in the physica I layer.Describe the three common transmission mode s(6 marks) c) State three functions of th e networking layer in th e OSI model 3 marks) SECTION I 3 ANSW ERANY THREE QUEST TIONS Questi on Th ree (12 marks)

Question One:<br /><br />a) <br />i) Multiplexing: Multiplexing is a technique used in networking to combine multiple data streams and transmit them simultaneously over a single communication channel. This allows for efficient utilization of the available bandwidth and enables multiple devices to share the same communication medium.<br /><br />ii) Switching: Switching is a method used in networking to connect multiple devices and allow them to communicate with each other. It involves the use of switches, which are devices that receive data from multiple sources and forward it to the appropriate destination based on the address information in the data packets.<br /><br />b) Unguided transmission refers to the transmission of electromagnetic waves without the use of a physical medium. Three examples of unguided transmission are:<br /><br />1. Radio transmission: Radio waves are transmitted through the air and can be received by any device equipped with a radio receiver. This is commonly used in wireless communication systems, such as cell phones and Wi-Fi networks.<br /><br />2. Infrared transmission: Infrared waves are transmitted through the air and can be received by devices equipped with infrared sensors. This is commonly used in remote controls and short-range wireless communication systems.<br /><br />3. Satellite transmission: Signals are transmitted from the ground to a satellite in orbit and then back to the ground. This allows for long-distance communication and is commonly used in satellite television and internet services.<br /><br />c) To calculate the network address, we need to perform a bitwise AND operation between the IP address and the subnet mask. In this case, the IP address is 192.168.1.10 and the subnet mask is 255.255.255.0. The network address is 192.168.1.0.<br /><br />d) A default gateway is a network device that serves as the default route for all traffic that does not have a specific destination address in the local network. It acts as an intermediary between the local network and other networks, allowing devices to communicate with devices on other networks by forwarding their traffic to the appropriate destination.<br /><br />Question Two:<br /><br />a) The three basic elements of layered network architecture are:<br /><br />1. Physical layer: This layer is responsible for the physical transmission of data over a communication medium. It defines the physical characteristics of the communication medium, such as voltage levels, frequency, and modulation.<br /><br />2. Data link layer: This layer is responsible for providing reliable data transfer between two devices over a shared communication medium. It ensures that data packets are transmitted without errors and are received in the correct order.<br /><br />3. Network layer: This layer is responsible for routing data between different networks. It determines the best path for data to travel and ensures that data packets are delivered to the correct destination.<br /><br />b) The three common transmission modes defined in the physical layer are:<br /><br />1. Simplex: In simplex mode, communication is unidirectional, meaning that data can only be transmitted in one direction. This is commonly used in scenarios where one device acts as a master and the other as a slave, such as in keyboard and mouse communication.<br /><br />2. Half-duplex: In half-duplex mode, communication is bidirectional, but data can only be transmitted in one direction at a time. This is commonly used in scenarios where two devices share a communication medium, such as in walkie-talkie communication.<br /><br />3. Full-duplex: In full-duplex mode, communication is bidirectional, and data can be transmitted in both directions simultaneously. This is commonly used in scenarios where high-speed data transfer is required, such as in Ethernet networks.<br /><br />c) The three functions of the networking layer in the OSI model are:<br /><br />1. Routing: The networking layer is responsible for determining the best path for data to travel between different networks. It uses routing protocols to select the most efficient route and ensure that data packets are delivered to the correct destination.<br /><br />2. Addressing: The networking layer is responsible for assigning unique addresses to each device on the network. This allows devices to identify each other and communicate with each other.<br /><br />3. Fragmentation: The networking layer is responsible for breaking down large data packets into smaller fragments that can be transmitted over the network. This ensures that data packets are small enough to fit within the maximum transmission unit (MTU) of the communication medium.