Questão 747175

• Banca: ESAF
• Órgão: CGU
• Ano: 2012
• Provas: ESAF - 2012 - CGU - Analista de Finanças e Controle - Infraestrutura de TI
• Disciplina: Redes de Computadores
• Assuntos: Protocolo

São variantes do protocolo PIM (Protocol-Independent Multicast):

• A. PIM Sparse Mode, PIM Dense Mode, Birectional PIM, PIM source-specific multicast.
  
• B. Shortest path PIM, PIM Dense Mode, Birectional PIM, Unidirectionsl PIM.
  
• C. PIM Sparse Mode, PIM Source Discovery, One-way PIM, PIM wide multicast.
  
• D. Shortest path PIM, PIM Source Discovery, One-way PIM, PIM source-specific multicast.
  
• E. Shortest path PIM, PIM Source Discovery, Birectional PIM, Unidirectional PIM.
  

Gabarito: A

Comentários

• Wikipedia responde rs
  
  
  • PIM Sparse Mode (PIM-SM) explicitly builds unidirectional shared trees rooted at a rendezvous point (RP) per group, and optionally creates shortest-path trees per source. PIM-SM generally scales fairly well for wide-area usage. See the PIM Internet Standard RFC 4601.
  • PIM Dense Mode (PIM-DM) uses dense multicast routing. It implicitly builds shortest-path trees by floodingmulticast traffic domain wide, and then pruning back branches of the tree where no receivers are present. PIM-DM is straightforward to implement but generally has poor scaling properties. The first multicast routing protocol, DVMRP used dense-mode multicast routing.^[1] See the PIM Internet Standard RFC 3973.
  • Bidirectional PIM explicitly builds shared bi-directional trees. It never builds a shortest path tree, so may have longer end-to-end delays than PIM-SM, but scales well because it needs no source-specific state. See Bidirectional PIM Internet Standard RFC 5015.
  • PIM source-specific multicast (PIM-SSM) builds trees that are rooted in just one source, offering a more secure and scalable model for a limited amount of applications (mostly broadcasting of content). In SSM, an IP datagram is transmitted by a source S to an SSM destination address G, and receivers can receive this datagram by subscribing to channel (S,G). See informationalRFC 3569.
  
  Referência: http://en.wikipedia.org/wiki/Protocol_Independent_Multicast