Questão 1217599

• Banca: VUNESP
• Órgão: DESENVOLVESP
• Ano: 2014
• Provas: VUNESP - 2014 - DESENVOLVESP - Analista - Grupo 6
• Disciplina: Inglês
• Assuntos: Interpretação de texto | Reading comprehension

       […]
       For mobile computers and telephones, cellular radio is the up-and-coming technology. GSM, CDPD, and CDMA are widely used.
       The IEEE 802 LANs are: CSMA/CD, token bus, and token ring. Each of these has its own unique advantages and disadvantages, and each has found its own user community and will probably continue to serve that community for years to come. Convergence to a single LAN standard is an unlikely event. A new addition to this family is DQDB, being sold as a MAN in many cities.
       An organization with multiple LANs often connects them with bridges. When a bridge connects two or more different kinds of LANs, new problems arise, some of them insoluble.
       […]

                     (Extraído de: Computer Networks, A.S. Tanenbaum, 3^rd Edition, Prentice-Hall, pg. 335)

De acordo com o texto, CSMA/CD, token bus e token ring são LANs padrão IEEE 802 que

• A. apesar de possuírem vantagens, ainda não foram plenamente descobertas.
• B. apresentam, cada uma, vantagens e desvantagens próprias.
• C. cada vez mais convergem para um único padrão de LAN, apesar de isso ter sido considerado improvável.
• D. estão organizadas em um tipo de rede múltipla, conectada em todos os seus extremos.
• E. incorporam inúmeros obstáculos, devendo, no futuro, ser substituídas.

Gabarito: B

Comentários

• b: "The IEEE 802 LANs are: CSMA/CD, token bus, and  token ring. Each of these has its own unique advantages and  disadvantages..."
  

• Típica questão em que é possível responder sem ler o texto.

   

  "Apresentam, cada uma, vantagens e desvantagens próprias". Essa afirmação genérica pode ser verdadeira para, praticamente, qualquer coisa à qual o enunciado estivesse se referindo.

• b-

  The IEEE 802 LANs are: CSMA/CD, token bus, and token ring. Each of these has its own unique advantages and disadvantages, and each has found its own user community and will probably continue to serve that community for years to come.

  Carrier-sense multiple access with collision detection (CSMA/CD) is a media access control (MAC) method for local area networking. It uses carrier-sensing to defer transmissions until no other stations are transmitting. This is used in combination with collision detection in which a transmitting station detects collisions by sensing transmissions from other stations while it is transmitting a frame. When this collision condition is detected, the station stops transmitting that frame, transmits a jam signal, and then waits for a random time interval before trying to resend the frame.

  https://en.wikipedia.org/wiki/Carrier-sense_multiple_access_with_collision_detection