Net Protocols pt2

The flashcards below were created by user fs356 on FreezingBlue Flashcards.

  1. There is no flow control mechanism in IP. ICMP's source quench message was designed to add a kind of flow control to IP. Explain this statements?
    ICMP message header format type4 code 0 is know as source quench and was designed to add a kind of flow and congestion control to the IP it informs the source that a datagram has been discarded due to congestion in a router or the destination host, the source must slow donw the sending of datagrams until the congestion is relieved
  2. In what 2 cases the time exceeded message is used?
    • 1)When datagram visits a router the value of this field is decrementd by 1 until it reaches 0 the router discards it
    • 2)When the destination host doesns't recive the frame withing a set time it discards it and sends a time exceeded message to the original source
  3. Mobile goes trough 3 phases to communicate with a remote host, explain?
    • To communicate with a remote host a mobile host goes through 3 phases
    • 1)Agent Discovery
    • 2)Registration
    • 3)Data Transfer
  4. Explain in details each of teh 3Mobile phases to communicate with a remote host?
    Agent Discovery: A mobile host must discover (learn the address of) a home agent before it leaves its home network. A mobile host must also discover a foreign agent after it has moved to foreign network. This discovery consists of learning the care of address as well as the foreign agent's address. The discovery involves 2 types of messages: advertisement and solicitation, when a mobile host has moved to a new network and has not received agent advertisements, it can initiate an agent soliciation

    Registration:After a mobile host has moved to a foreign network and discovered the foreign agent it must register. To register with the foreign agent and the home agent, themobile host uses a registration request and registration reply

    Data Transfer: After agent discovery and registration a mobile host can communicate with a remote host
  5. Persistance vs Nonpersistance?
    • Persistance connection:
    • The server keeps a TCP conneciton open for more requests after sending a response. The server can close the connection at the request of a client or if a time-out has been reached

    • Nonpersistent connection:
    • One TCP connection is made for each request/response
    • Every connection requires 1 handshake
    • Is not instantaneous
    • Imposes high overhead on the server becuase the server needs N + 1 different buffers and requires a slow start procedure each time a connection is opened
Card Set:
Net Protocols pt2
2012-05-08 14:21:34

Networking Protocols
Show Answers: