Questão 7441

• Banca: ESAF
• Órgão: CGU
• Ano: 2004
• Provas: ESAF - 2004 - CGU - Analista de Finanças e Controle - Tecnologia da Informação - Prova 3
• Disciplina: Redes de Computadores
• Assuntos: Transmissão de Dados

O IRC é um sistema de conferência em tempo real, multiusuário, baseado em texto. Os usuários executam programas cliente IRC para se conectar com servidores IRC. Com relação às características de filtragem de pacotes do IRC é correto afirmar que

• A. clientes IRC e servidores IRC que fazem contato com outros servidores IRC usam portas abaixo de 1023.
• B. toda comunicação IRC é feita pela porta 80, da mesma forma que o protocolo HTTP.
• C. o DCC (Direct Client Connections) torna possível dois clientes IRC negociarem e estabelecerem uma conexão TCP diretamente entre eles, contornando todos os servidores, exceto para a conexão inicial.
• D. o IRC é baseado tanto no UDP quanto no TCP.
• E. clientes IRC usam a porta 25 para se comunicarem com outros clientes IRC que usam DCC (Direct Client Connections).

Gabarito: C

Comentários

• Direct Client Connection (DCC)
  
  Now, if you've gotten the hang of some of the of the ways of communicating, there is one other area that can assist in communicating, as well as in file transfers via IRC.
  Direct Client Connection (DCC) has 3 basic uses for most IRC users: Chatting, Sending files, and Retrieving files.
  As the name implies, DCC is a direct link between two clients. In other words, there is no server that the connection goes through. Let's say for instance I have a DCC connection between myself and we'll say Quake. This means things I send over a DCC connection, it goes directly through my computer to his system, without any servers coming into play. Here are the three Main DCC options:
  
  
  DCC SEND: It's a way to send files out from your computer to another person.
  
  Format: /DCC SEND [nick] [filename]
  Example: /DCC SEND Kaite MyScript.IRC
  
  This is the way that a lot of Warez (illegally copied software) gets around on IRC, and is partly responsible for some of the negative publicity about IRC. However, for transferring scripts, bots, jpegs, gifs, text files, documents, it is a very easy way of doing it (you can sit and chat with the person you're sending to WHILE it is being sent).
  
  
  DCC GET: How you receive the files that other people send to you.
  
  Format: /DCC GET [nick] [filename]
  Example: /DCC GET Edge MyScript.IRC
  
  
  DCC CHAT: Possibly one of the most intriguing commands, simply due to the fact that it works similar to the old "talk functions", except you can establish many of them and still be on IRC, making it a much nicer prospect. Think of it as being able to send msgs directly to the other person's machine. So, if my server is lagging from yours, but I have a DCC chat connection to you, I can msg you without any more of a delay then if we were on the same server, and in many occasions, as fast as being on the same system.
  
  Format: /DCC CHAT [nick]
  Example: /DCC CHAT Vampiress
  
• alguém que conhece bem a língua inglesa poderia traduzir? hehehe
• Letra C. O IRC, que no final da década de 90 era popular com o pIRC e mIRC, possibilita o bate-papo entre vários usuários conectados em uma sala (canal de IRC). O DCC é o precursor da 'vídeo conferência', porque estabelece uma conexão entre os usuários para conversas privadas. É 'a sala de bate papo reservada' que existe no UOL, por exemplo.