Data Communications - Data Link Protocol & Lan Devices

A repeater is an electronic device that receives a signal and amplifies it to increase its strength or retransmits it to extend its coverage. It is used to overcome signal degradation and enable the signal to travel longer distances or pass through obstacles.

The given statement describes the behavior of the Stop and Wait Protocol. In this protocol, the transmitting station sends one message frame and then waits for an acknowledgment from the receiving station before sending the next message frame. This ensures that each frame is successfully received and acknowledged before proceeding to the next frame. It is a simple and reliable protocol but can be inefficient in terms of bandwidth utilization.

A Sliding Window Protocol Using Selective Repeat is the correct answer because this protocol accepts frames out of order but ensures that the packets are passed to the network layer in order. It also utilizes a timer, and when the timer expires, only the frames associated with that timer are retransmitted. This protocol allows for efficient and reliable data transmission in a network.

A gateway is a network node that is capable of connecting and interfacing with another network that operates on different protocols. It acts as a translator or bridge between the two networks, allowing for communication and data transfer. The term "gateway" can be written in different cases (lowercase, uppercase, or capitalized) but it refers to the same concept.

A router is a device that contains software enabling it to determine the best path for a transmission between addresses. It operates in the physical, data link, and network layers of the OSI model. A router is responsible for directing network traffic and ensuring that data packets are delivered efficiently to their intended destinations. It uses routing protocols to make decisions about the most optimal path for data transmission based on factors such as network congestion, speed, and reliability.

False. Both switches and bridges do not have the same architecture. While they both operate at the data link layer of the OSI model and are used to connect multiple network devices, switches are more advanced than bridges. Switches use MAC addresses to forward data packets to the appropriate destination device, allowing for faster and more efficient network communication. Bridges, on the other hand, use physical addresses to forward data packets, which can result in slower network performance compared to switches.

Repeaters are not more expensive than gateways. Repeaters are relatively simple devices that are used to extend the range of a network by amplifying and retransmitting signals. They do not require complex hardware or additional functionalities, which makes them generally less expensive than gateways. Gateways, on the other hand, are more sophisticated devices that act as interfaces between different networks, translating protocols and facilitating communication between them. Due to their additional functionalities and complexity, gateways tend to be more expensive than repeaters. Therefore, the statement that repeaters are more expensive than gateways is false.

Latency refers to the amount of delay that occurs when data frames pass through a network device. It is a measure of the time it takes for data to travel from the source to the destination. Latency can be influenced by various factors such as network congestion, distance, and processing time. It is an important metric in network performance as it can impact the overall speed and responsiveness of a network.

A hub is a device that connects multiple twisted pair or fiber optic Ethernet devices together, allowing them to function as a single network segment.

Bridges do not propagate errors. Repeaters, on the other hand, amplify and regenerate signals, but they do not provide electrical isolation. Therefore, the given statement is false.

The given correct answer is "A Simplex Protocol for a Noisy Channel". This protocol is suitable for transmitting data over a noisy channel where there is a possibility of data corruption or loss. The simplex protocol allows data to flow in only one direction, which means it is unidirectional. It is designed to handle unreliable channels by incorporating error detection and correction mechanisms to ensure the integrity of the transmitted data.

ISO 4335 is a standard that refers to the elements of procedure. It provides guidelines and specifications for the elements that should be included in procedures for various processes. The number "4335" is the specific identification number of this ISO standard. This standard ensures consistency and quality in procedures followed by organizations, promoting efficiency and effectiveness in their operations.

The Sliding Window Protocol allows the source station to transmit multiple frames without waiting for an acknowledgment. It uses a sliding window mechanism to keep track of the frames sent and received. The sender can continuously send frames until the window is full, and the receiver can acknowledge the frames in the window. This protocol improves efficiency by allowing for pipelining of frames, reducing the amount of time wasted on waiting for acknowledgments.

A bridge is a device that connects two or more individual LANs or LAN segments and allows for communication between networks that have different types of architectures. It acts as a link between these networks, enabling data transmission and facilitating connectivity. The use of different capitalization for the word "bridge" does not change its meaning or functionality in this context.

A protocol machine is a sender or receiver that is always in a specific state at every instant of time. This machine consists of all values of its variables, including the program counter. In the context of communication protocols, a protocol machine follows a set of rules and procedures to ensure reliable and orderly communication between two or more entities. It is responsible for handling tasks such as message transmission, error detection using checksums, and transitioning between different states based on the protocol's specifications.

A network bridge is a device that connects multiple network segments together, allowing them to communicate with each other. One of the disadvantages of a network bridge is that it introduces store and forward delays. When data is transmitted across the bridge, it is first stored in a buffer before being forwarded to the destination. This buffering process can introduce delays in the transmission of data.

ISO 3309 is the correct answer because it is the ISO standard that specifically refers to frame structure. The number "3309" is the specific identification number of this ISO standard. ISO standards are internationally recognized and provide guidelines and specifications for various industries and processes. In this case, ISO 3309 provides the standard for frame structure, which is likely relevant to a specific industry or field that deals with frames.

The Sliding Window Protocol Using Go Back N allows multiple outstanding frames without waiting for an acknowledgment. In this protocol, the sender can transmit multiple frames before receiving an acknowledgment, which increases the efficiency of data transmission. If an acknowledgment is not received within a certain time period, the sender retransmits all the frames starting from the frame that was not acknowledged, hence the name "Go Back N". This protocol is commonly used in network communication to ensure reliable and efficient data transfer.

The Simplex Stop and Wait Protocol is the most suitable choice for a situation where the transmission is one-directional and assumed to be error-free, but the receiver has a finite buffer capacity and processing speed. This protocol allows for the transmission of data in only one direction, from sender to receiver, and ensures that the receiver acknowledges each received packet before the sender can send the next one. This helps in managing the limited buffer capacity and processing speed of the receiver, as it allows for a controlled flow of data.

The given explanation suggests that the correct answer is "Unrestricted Simplex Protocol" because it provides for data transmission in one direction only, without any error checking or acknowledgement from the receiver. It assumes that the receiver can process all the input infinitely quickly, indicating that there is no need for any feedback or flow control mechanisms.