Which of the following most accurately describes the architecture of the Internet in terms of its scalability and fault tolerance? A. Centralized network of dedicated circuits with... Which of the following most accurately describes the architecture of the Internet in terms of its scalability and fault tolerance? A. Centralized network of dedicated circuits with redundant paths B. Distributed network with autonomous ISPs that interact via standardized protocols C. A peer-to-peer system of interconnected routers governed by proprietary protocols D. Hierarchical network where all nodes connect through a global ISP Answer: B The Internet Engineering Task Force (IETF) publishes standards in which format, and what is the significance of these documents? A. TCP/IP models; they define the architecture of all modern networks. B. IEEE Standards; they dictate how hardware components are manufactured. C. RFC (Request for Comments); these documents outline proposed and accepted Internet protocols. D. ISO protocols; they formalize the global structure of networking layers. Answer: C Which of the following accurately represents the concept of 'end-to-end' communication in the Internet, and why is it significant? A. The path of data packets is determined only at the network's core, ensuring low latency. B. Applications on host systems are responsible for ensuring the correctness and reliability of communication, allowing for a simple network core. C. Routers at the network core manage both packet forwarding and error correction, ensuring reliable delivery. D. End-to-end communication refers to the direct communication between ISPs, ensuring faster data delivery. Answer: B How do Internet protocols such as HTTP and TCP differ in terms of their functional responsibilities? A. HTTP manages error correction, while TCP handles session management. B. HTTP is responsible for data integrity, and TCP facilitates browser-server interaction. C. TCP ensures reliable packet delivery, while HTTP operates at the application layer, facilitating web communication. D. HTTP operates at the physical layer, while TCP manages data transport between networks. Answer: C Why is the concept of protocol layering essential in network design, and what is the main challenge it introduces? A. Protocol layering simplifies network design by dividing communication tasks, but increases the likelihood of congestion in high-traffic networks. B. It introduces modularity and abstraction in communication processes but can lead to overhead when data is encapsulated across multiple layers. C. Layering ensures that each device can operate independently but makes routing between networks significantly slower. D. It is necessary to ensure hardware compatibility but increases the cost of transmission by requiring more expensive routers. Answer: B Network Edge: Which of the following best describes the role of data centers in a client-server architecture, particularly concerning scalability? A. Data centers store and manage routing tables for the entire network, enhancing scalability by centralizing routing. B. They host multiple redundant servers that manage user requests, increasing scalability through load balancing and resource replication. C. Data centers act as intermediary nodes that store intermediate packet states, which allows for faster data recovery. D. Data centers handle session initiation for large-scale web traffic, preventing congestion in packet-switched networks. Answer: B In terms of network scalability, which design consideration at the edge is most likely to impact performance as the number of connected devices increases? A. The number of routers at the core B. The transmission rate between connected hosts and access networks C. The number of protocols supported by the end systems D. The geographical distance between the data centers Answer: B What is a key disadvantage of using traditional client-server architecture in comparison to peer-to-peer systems, particularly in large-scale networks? A. Client-server models lead to increased packet loss when multiple clients communicate simultaneously. B. Client-server architecture requires significant server-side resources, which limit scalability as the network grows. C. Peer-to-peer systems offer lower reliability, but the client-server model suffers from increased routing complexity. D. Client-server systems are more susceptible to network failures, while peer-to-peer systems provide fixed routing paths. Answer: B Which of the following accurately describes the challenge faced by mobile access networks in comparison to wired access networks? A. Wired networks suffer from packet loss due to interference, while mobile networks maintain a stable bandwidth. B. Mobile networks must contend with more significant propagation delays and fluctuating bandwidth due to user mobility and interference. C. Wired networks have lower latency, but mobile networks can handle more simultaneous users due to packet prioritization. D. Mobile networks avoid queueing delays by prioritizing bandwidth allocation for high-speed users. Answer: B What is the relationship between transmission rate (R), packet size (L), and delay in packet-switched networks, and how does this impact network performance? A. Delay is inversely proportional to both R and L; increasing packet size or transmission rate reduces delay. B. Increasing packet size increases delay, but increasing transmission rate reduces it; the balance between R and L impacts overall performance. C. Transmission rate has no impact on delay, but packet size directly determines the queuing delay. D. The delay is directly proportional to both R and L; decreasing either reduces overall latency. Answer: B Network Core: In packet-switched networks, which mechanism ensures that routers can handle variable traffic loads without causing packet loss? A. Forwarding protocols that dynamically assign buffers B. Routing protocols that prioritize packets based on size C. Queuing and congestion control algorithms that manage incoming traffic at routers D. Fixed bandwidth allocation for each incoming packet to minimize queuing Answer: C Why is packet-switching considered more efficient than circuit-switching in most data networks, and what is the associated drawback? A. Packet-switching dynamically allocates resources based on demand, but can suffer from packet loss during congestion. B. Packet-switching reserves bandwidth, ensuring predictable performance, but introduces significant overhead in encapsulating packets. C. Circuit-switching offers more reliable communication, but packet-switching leads to reduced latency in high-congestion environments. D. Packet-switching avoids queuing delays, but circuit-switching ensures that all packets arrive in order. Answer: A In the context of routing algorithms, what does the term 'convergence' refer to, and why is it critical for network performance? A. The process by which routers communicate to establish end-to-end circuits, reducing latency. B. The dynamic recalculation of routes after a topology change to ensure all routers have updated forwarding tables. C. The mechanism through which routing loops are avoided by assigning unique forwarding tables to each router. D. The process by which packets are encapsulated with the appropriate headers as they move through the network. Answer: B In packet-switching, what is the significance of the store-and-forward mechanism, and how does it impact the overall packet delay? A. It reduces overall transmission time by storing small packets for transmission, but increases delay for large packets. B. It ensures that each packet is verified before transmission, reducing the likelihood of errors but introducing queuing delay. C. It allows routers to handle packets sequentially, where a packet must be fully received before forwarding, adding to transmission delay. D. It prioritizes large packets for transmission to minimize overall network congestion but increases propagation delay. Answer: C Which aspect of packet-switching makes it more vulnerable to excessive congestion, and how can this be mitigated? A. Lack of dedicated resources for each transmission; congestion control algorithms are used to dynamically allocate bandwidth. B. Reliance on shared access links; increasing the number of routers mitigates congestion by reducing link load. C. The use of queuing buffers; congestion is mitigated by reducing packet size and increasing transmission rate. D. The random allocation of bandwidth across users; increasing the number of end hosts in a network resolves congestion. Answer: A Network Access and Physical Media: Which of the following physical media offers the highest immunity to electromagnetic interference, and what is the associated trade-off? A. Twisted pair cables; lower cost but increased attenuation over long distances B. Coaxial cables; high immunity but lower transmission speeds compared to fiber optics C. Fiber optic cables; high immunity to interference but more expensive and complex to install D. Wireless radio; immune to physical obstruction but more susceptible to noise from nearby devices Answer: C Why does Frequency Division Multiplexing (FDM) in cable-based access networks allow for higher transmission speeds compared to Time Division Multiplexing (TDM)? A. FDM divides the cable bandwidth into different frequency bands, allowing simultaneous transmission across multiple channels. B. FDM dynamically adjusts transmission rates based on network congestion, unlike TDM which uses fixed time slots. C. TDM limits each user to a narrow frequency band, while FDM allows each user to access the full cable bandwidth. D. FDM eliminates the need for routers by transmitting data directly over physical media, whereas TDM relies on packet forwarding. Answer: A Which of the following factors most directly influences the propagation delay in a fiber optic cable? A. The number of routers between the source and destination B. The packet size and transmission rate C. The distance between the transmitter and receiver D. The attenuation properties of the fiber optic material Answer: C In wireless networks, how does the propagation environment (e.g., reflection and interference) impact overall network performance? A. It reduces propagation delay by enhancing signal strength. B. It leads to increased packet loss and retransmissions due to multipath interference. C. It improves bandwidth allocation for users in urban environments. D. It enhances the queuing delay due to signal reflection off physical objects. Answer: B Which of the following describes a primary advantage of hybrid fiber-coaxial (HFC) networks in cable-based access? A. They offer a symmetrical transmission rate between upstream and downstream traffic. B. HFC networks combine the high speed of fiber optics with the wider availability of coaxial cables, providing both capacity and coverage. C. HFC eliminates interference in long-distance communications by replacing all copper wiring with fiber optics. D. HFC networks prioritize upstream communication over downstream communication to reduce queuing delay. Answer: B Delay and Loss in Packet-Switched Networks: What is the relationship between transmission rate (R), propagation delay, and queuing delay in packet-switched networks? A. Queuing delay is only impacted by the transmission rate, while propagation delay depends on the distance between nodes. B. Both queuing and propagation delays increase linearly with transmission rate; packet size has no effect. C. Propagation delay is proportional to the number of intermediate routers, while queuing delay depends on buffer size and link congestion. D. Queuing delay increases with transmission rate, while propagation delay is inversely proportional to packet size. Answer: C Which of the following accurately describes how queueing delay increases as packet arrival rate approaches link capacity? A. Queueing delay increases linearly as packet arrival rate reaches link capacity. B. Queueing delay increases exponentially as packet arrival rate exceeds link capacity, leading to packet loss. C. Queueing delay decreases as the arrival rate increases, optimizing bandwidth usage. D. Queueing delay remains constant once packet arrival rate equals link capacity due to fixed buffer size. Answer: B In packet-switched networks, why does increasing the size of a router's buffer not always reduce packet loss during congestion? A. Larger buffers lead to longer processing delays, which increases packet delay variation (jitter). B. Increasing buffer size causes routers to drop larger packets, increasing the likelihood of retransmissions. C. Larger buffers increase the time required to transmit packets, leading to bandwidth underutilization. D. Larger buffers only reduce packet loss if the transmission rate is increased simultaneously, otherwise queuing delays become excessive. Answer: A Which of the following correctly explains the concept of propagation delay, and how it differs from queuing delay? A. Propagation delay refers to the time a packet spends in the router’s buffer, while queuing delay refers to the time needed for the packet to propagate across a link. B. Propagation delay is dependent on the distance between sender and receiver, whereas queuing delay depends on link congestion and processing speed. C. Propagation delay occurs when a packet is dropped due to network congestion, while queuing delay is related to packet retransmission. D. Propagation delay is a constant value for all networks, while queuing delay increases with packet size and arrival rate. Answer: B Which scenario would likely cause a router to drop packets due to buffer overflow, and how can this be mitigated? A. When packet arrival rate consistently exceeds the transmission rate; this can be mitigated by reducing packet size and adjusting buffer size. B. When the propagation delay between routers is too long; this can be mitigated by increasing the transmission rate. C. When the link capacity is shared by too many users; this can be mitigated by decreasing the buffer size to reduce queuing. D. When circuit switching is used instead of packet switching; this can be mitigated by allocating dedicated bandwidth to each transmission. Answer: A Protocol Layers and Service Models: Why does the Internet protocol stack omit the presentation and session layers found in the OSI model, and what are the implications for application design? A. The Internet stack assumes that data formatting and encryption are handled at the application layer, simplifying the stack but requiring more complex application development. B. The presentation and session layers are incorporated into the link and physical layers, leading to greater efficiency in routing. C. The session layer is integrated into the network layer, reducing the need for error detection protocols at the application layer. D. The presentation and session layers are omitted to prevent queuing delays, requiring applications to manage transport-level retransmissions. Answer: A In the layered Internet protocol stack, which layer is responsible for error correction and reliable data transfer between processes? A. Application layer B. Transport layer C. Network layer D. Link layer Answer: B Why is the encapsulation process in the Internet protocol stack critical for data transmission, and what challenge does it introduce? A. Encapsulation allows each layer to add its own header to the data packet, ensuring the correct routing of packets, but it increases overhead and latency. B. It ensures that data packets are encrypted before transmission, which adds complexity to decryption at the destination. C. Encapsulation allows for dynamic routing of packets, but introduces significant queuing delays in the network core. D. It prioritizes data packets based on the transport protocol used, leading to congestion in routers with large buffers. Answer: A Which of the following protocols operates at the network layer and is responsible for routing packets across multiple networks? A. HTTP B. TCP C. IP D. DNS Answer: C How does the Internet protocol stack achieve modularity, and why is this advantageous for network design and maintenance? A. By dividing network functions into independent layers, the Internet stack allows for easier protocol updates without disrupting the entire network, but it introduces complexity in packet encapsulation. B. The stack eliminates redundancy in routing and forwarding tasks, ensuring faster packet delivery at the expense of compatibility across different network architectures. C. Modularity allows for faster transmission speeds but limits the number of protocols that can be implemented in each layer. D. By combining the network and transport layers, the Internet stack achieves greater flexibility in routing and congestion control, but increases processing delay. Answer: A Read more