Computer Science 825
                           Quiz 1           Name _______________________

Terminology:  the very highest layer is the APPLICATION LAYER = Layer N
              the very lowest  layer is the PHYSICAL LAYER    = Layer 1

 1. Protocol headers used by a layer N are handled by layer K (K > N)
    as follows:

   a. The are removed before       b. They are treated as user data.
      the packet arrives at
      Layer K

   c. They are deleted by layer K.

 2. A Layer N peer protocol definition is most closely related to specifying
    the way in which layer N interacts with:

    a. Layer N - 1                b. Layer N + 1

    c. Layer N at other nodes
       in the network.

 3. a. Which of the seven layers of the ISO model is the LOWEST
       layer resident in host computers.



    b. Which of the seven layers of the ISO model is responsible
       for code conversions.



    c. At which of the seven layers is it necessary that all
       nodes in the network speak a common peer protocol.



    d. At which of the seven layers is the TCP protocol located.



 4. How many signalling states are needed to achieve a bit rate
    of 65536 bits / second while signalling at a baud rate of 2048.
















 5. The present trend at the network and datalink layer is to:

    a. Greater use of reliable       b. Greater use of reliable protocols
       protocols at both layers         at the network layer but unreliable
                                        protocols at the datalink layer.

    c. Greater use of reliable       d. Greater use of unreliable protocols
       protocols at the datalink        at both layers.
       layer but greater use of
       unreliable at the network layer

 6. Enumerate four DISTINCT actions that a protocol might engage in to
    earn the title "unreliable:

    1 -

    2 -

    3 -

    4 -

7. Place the following protocols at the correct location in the
   boxes below:  TCP, IP, ATM


                   Connection        Connection
                   Oriented             Less
               ___________________________________
               |                 |               |
     Reliable  |                 |               |
               |                 |               |
               |_________________|_______________|
               |                 |               |
     Unreliable|                 |               |
               |                 |               |
               |_________________|_______________|


8. Some applications (like file transfer) REQUIRE reliable service.
   It is possible to provide such service within upper layer protocols.
   However, we identified two factors that could make the use of RELIABLE
   data link protocols desirable and/or necessary. Identify them:

   a -


   b -