Examen General De Tcd Primavera 2013

The given statement is true. TCP (Transmission Control Protocol) is a connection-oriented protocol, which means it establishes a connection between the sender and receiver before transmitting data. It ensures reliable and ordered delivery of data packets by implementing mechanisms like acknowledgment and retransmission. On the other hand, UDP (User Datagram Protocol) is a connectionless protocol, where data packets are sent without establishing a connection. It does not guarantee reliable delivery or ordering of packets, but it is faster and more efficient for applications that do not require these features.

The statement is true because the three phases of connection-oriented communication are indeed establishment, transfer, and release. In the establishment phase, the communication channel is set up between the sender and receiver. In the transfer phase, the data is transmitted from the sender to the receiver. Finally, in the release phase, the communication channel is terminated or released. These three phases ensure a reliable and orderly communication process.

In the context of network protocols, negotiation refers to the process of reaching an agreement between two parties on certain parameters or values used during communication. This agreement ensures that both parties are on the same page and can effectively communicate with each other. Therefore, the statement "La 'negociación' en el contexto de protocolos de red tiene que ver con conseguir que ambas partes estén de acuerdo en algunos parámetros o valores que se utilizan durante la comunicación" is true.

The statement is true. The speed of propagation in copper and fiber is indeed 200,000 km/second or 200 meters per microsecond. This means that signals can travel at this speed through these mediums.

The Nyquist theorem states that the maximum data rate of a communication channel is twice the bandwidth of the channel. In the case of fiber optic and copper wire, both have finite bandwidths, so the Nyquist theorem applies to them. Therefore, it can be concluded that the statement "Se cumple el teorema de Nyquist para la fibra óptica y el alambre de cobre?" (Does the Nyquist theorem hold for fiber optic and copper wire?) is true.

The statement is false because "4" is not the number of threads inside the UTP cable for wired network transmission. The correct answer is that UTP cables typically have 8 threads or wires twisted in pairs, which are used for transmitting data in wired networks.

The correct answer is "Sesion" because the session layer in the OSI model is responsible for establishing, managing, and terminating sessions between two communicating devices. This layer ensures that a reliable and secure connection is maintained between the computers while they are transmitting data of any kind.

A gas pipeline is not a simplex system because it allows for bidirectional flow of gas. It is also not a total duplex system because it does not have completely separate channels for sending and receiving gas simultaneously. Therefore, the correct answer is semidúplex, which means that it has the capability to transmit and receive gas, but not at the same time.

A multimeter is a device used for maintenance and diagnosing faults in a computer network. It performs an analysis of a specific part of the circuit to determine the location of the problem. By analyzing the circuit, it helps in identifying any faults or issues that may be affecting the network's performance. This analysis can be done by measuring voltage, current, and resistance at different points in the circuit. By validating the location of the problem, technicians can then take appropriate actions to resolve the issue and ensure the smooth functioning of the network.

Un módem QAM-64 de dúplex total utiliza dos frecuencias, una para la transmisión de datos aguas arriba (del usuario al proveedor de servicios) y otra para la transmisión de datos aguas abajo (del proveedor de servicios al usuario). Esta configuración permite la comunicación bidireccional y simultánea entre el usuario y el proveedor de servicios.

300 MH es un ejemplo de radiofrecuencia de Ultra Alta Frecuencia. La unidad de medida de la frecuencia de las ondas de radio es el Hertz (Hz), y el prefijo "M" representa el factor de multiplicación de un millón. Por lo tanto, 300 MH representa una frecuencia de 300 millones de Hertz, lo cual está dentro del rango de Ultra Alta Frecuencia.

The correct answer is 125 microsegundos. PCM (Pulse Code Modulation) is a method used to digitally represent analog signals. The time at which each sample is taken is known as the sampling interval. In PCM, the sampling interval is fixed and determines the accuracy of the digital representation. A smaller sampling interval allows for a more accurate representation of the analog signal. In this case, a sampling interval of 125 microsegundos is considered the fixed sampling interval for PCM.

The essential difference between message switching and packet switching is that message switching allows for the transmission of data units that can be arbitrarily long, while packet switching has a maximum packet size. If a message is longer than the maximum packet size, it is divided into multiple packets.

The correct answer is "Para enviar una señal T1 necesitamos Hlog2 (1 + S / N) = 1.544 x 106 con H = 50.000. Esto produce S / N = 230 - 1, que es aproximadamente 93 dB." This is because the question asks for the signal-to-noise ratio (S/N) needed to put a T1 carrier on a 50 kHz line. The formula Hlog2 (1 + S / N) = 1.544 x 106 is used to calculate the required S/N ratio, where H represents the bandwidth (50,000 Hz in this case). Plugging in the values, we get S/N = 230 - 1, which is approximately 93 dB.

A codec is responsible for converting an arbitrary analog signal into a digital signal, while a modem's demodulator converts a modulated sinusoidal wave into a digital signal. Therefore, the main difference between the two is the type of input signal they accept. A codec accepts an arbitrary analog signal, while a modem's demodulator accepts a modulated sinusoidal wave. Both devices ultimately generate a digital signal as output.

The OSI reference model does not have both connection-oriented and connectionless services at the data link layer. The data link layer in the OSI model provides connection-oriented services, which ensure reliable transmission of data over a physical link. On the other hand, the network layer in the OSI model provides connectionless services, which do not guarantee reliable delivery of data. Therefore, the statement is false.

The correct answer is A) 64 Kbps, B) 32 Kbps, C) 8 Kbps. The CCITT method with a standard rate of 2.048 Mbps can transmit 64 Kbps of actual data. DPCM with a relative signal value of 4 bits can transmit 32 Kbps of actual data. Modulation delta can transmit 8 Kbps of actual data.

The correct answer states that with DIBIT encoding, two bits are sent per sample, while with T1, 7 bits are sent per period. The respective data rates are 16 Kbps and 56. This means that the DIBIT encoding has a lower data rate compared to T1.

The correct answer is "funciona a 27 Mbps, la interfaz de usuario es casi siempre de 10-Mbps". This means that the cable user can receive data at a speed of 27 Mbps, but the user interface is typically limited to 10 Mbps. This suggests that the network is capable of delivering data at a faster rate than the user interface can handle, resulting in a slower data reception for the user.