Question 1 Tenta (True/False)

Time and frequency division multiplexing schemes are techniques used to divide the available bandwidth of a link into separate, allocatable pieces. In time division multiplexing, the link's bandwidth is divided into time slots, and each slot is allocated to a different user or channel. In frequency division multiplexing, the link's bandwidth is divided into different frequency bands, and each band is allocated to a different user or channel. These schemes allow multiple users or channels to share the same link, increasing the efficiency and capacity of the communication system. Therefore, the statement is true.

The given statement is true because it accurately describes the definition of the Internet. The Internet is a global network of interconnected computers and devices that communicate with each other through communication links and routers. These devices, known as hosts, run various network applications such as web browsing, email, and file sharing. Therefore, the statement correctly defines the Internet as a network infrastructure consisting of hosts running network applications interconnected through communication links and routers.

The statement is true because protocols are the set of rules and guidelines that govern the communication between devices on the internet. These protocols ensure that data is transmitted accurately and efficiently across the network. Without protocols, there would be no standardized way for devices to communicate with each other, leading to chaos and a lack of interoperability. Therefore, it can be concluded that all communication activity in the internet is indeed governed by protocols.

Time and frequency division multiplexing schemes are indeed used to divide the link bandwidth into separately allocatable pieces. In time division multiplexing, the available bandwidth is divided into time slots, and each slot is allocated to a different user or channel. In frequency division multiplexing, the available bandwidth is divided into different frequency bands, and each band is allocated to a different user or channel. Both schemes allow multiple users or channels to share the same physical link by dividing the bandwidth into separate portions. Therefore, the given statement is true.

In datagram networks, packets between the same source-destination pair may take different paths. This is because datagram networks use a connectionless approach, where each packet is treated independently and can be routed dynamically based on network conditions. Unlike circuit-switched networks, which establish a dedicated path for the entire communication, datagram networks allow packets to be routed through different paths, providing flexibility and resilience against network failures. Therefore, the statement is true.

HTTP response messages may have an empty message body because not all responses require a body to be included. For example, a response with a status code of 204 (No Content) indicates that the request was successful, but there is no additional content to be returned. Similarly, a response with a status code of 304 (Not Modified) indicates that the requested resource has not been modified since the last request, so there is no need to include the resource again in the response body. Therefore, it is true that HTTP response messages may have an empty message body.

Internet transport-layer protocols, such as TCP and UDP, do not provide delay and bandwidth guarantees. These protocols are designed to provide reliable and efficient data transfer over the internet, but they do not guarantee specific levels of delay or bandwidth. The actual delay and bandwidth experienced by a network connection can vary depending on various factors such as network congestion, distance, and quality of the network infrastructure. Therefore, the statement that internet transport-layer protocols provide delay and bandwidth guarantees is false.

The statement is false because when a user requests a web page that consists of some text and two images, the client will send only one request message to the server. The server will then respond with a single response message that includes the requested web page along with the text and images. Therefore, the client will receive only one response message, not three.

Transfer across TCP streams is full duplex means that data can be sent and received simultaneously in both directions on a TCP connection. This is achieved through the use of separate channels for sending and receiving data, allowing for bidirectional communication. Full duplex communication is important in scenarios where real-time data exchange is required, such as video conferencing or online gaming. TCP ensures reliable and ordered delivery of data, making it suitable for applications that require both sending and receiving data simultaneously. Therefore, the given answer, True, is correct.

ICMP (Internet Control Message Protocol) messages are indeed carried in IP datagrams. ICMP is a network protocol that is used to send error messages and operational information about network conditions. These messages are encapsulated within IP datagrams, which are packets of data that are transmitted over IP networks. Therefore, the statement "ICMP messages are carried in IP datagrams" is correct.

Using TCP, a connection is established through a three-way handshake process. This process involves the exchange of three messages, not two, between the client and the server. The first message is sent by the client to the server to initiate the connection request. The second message is sent by the server to acknowledge the request and confirm the connection. Finally, the third message is sent by the client to acknowledge the server's confirmation. Therefore, the statement that only two messages are exchanged before a connection exists is false.

The statement is true because end systems, also known as hosts, communicate with each other using either server or client models. In the server model, one end system acts as a server and provides services to other end systems, which act as clients. In the client model, an end system requests and receives services from a server. This communication can occur over a network using protocols such as TCP/IP.

In datagram networks, the time a datagram spends in a router buffer is not controlled by the round trip time. The round trip time refers to the time it takes for a packet to travel from the source to the destination and back. It does not determine the time a datagram spends in a router buffer. The time spent in a router buffer is influenced by factors such as network congestion, the size of the buffer, and the processing speed of the router.

UDP (User Datagram Protocol) is a connectionless protocol that does not require a connection setup before transmitting data. It also does not provide congestion control, which means that it does not manage or regulate the flow of data to avoid network congestion. Therefore, the statement that UDP service requires connection setup and provides congestion control is false.

Datagram networks do not require call setup at the network layer. In a datagram network, each packet is treated independently and does not require any prior setup or connection establishment. Datagram networks are connectionless and do not maintain any state information about the ongoing communication. Therefore, the statement that datagram networks require call setup at the network layer is false.

The statement is false because circuit switching is not used to establish dedicated network paths that may be shared by other end systems. In circuit switching, a dedicated communication path is established between the sender and receiver, and this path is exclusively used by them until the communication is complete. It is not shared with other end systems.

The statement is false. Network Address Translation (NAT) is used to translate private IP addresses to public IP addresses and vice versa, allowing devices on a private network to communicate with devices on the internet. NAT does not expand the available device address space through the use of port numbers. The end-end argument at the network layer is satisfied by other protocols such as IPv6, which provides a larger address space.

Both UDP (User Datagram Protocol) and TCP (Transmission Control Protocol) are transport layer protocols that are responsible for delivering data packets over a network. In order for the data to be successfully transmitted and received, the applications using these protocols need to recognize and interpret the data formats. This is because UDP and TCP do not perform any data formatting or interpretation themselves. Therefore, the statement that both UDP and TCP require that the applications recognize their own data formats is true.

Transport services and protocols do not provide logical communication between hosts. They are responsible for providing end-to-end communication services, including segmentation, reassembly, and error control, but they do not establish logical communication between hosts. This is the responsibility of the network layer protocols.

The window size in TCP is not used to avoid congestion within the IP network. The window size is a parameter that determines the amount of data that can be sent without receiving an acknowledgment. It is used for flow control, to ensure that the sender does not overwhelm the receiver with data. Congestion control in TCP is achieved through other mechanisms such as slow start, congestion avoidance, and fast retransmit. Therefore, the statement is false.