Computer Science 851
                           Quiz 1           Name _______________________

1. a. Identify one layer of the ISO/OSI 7 layer stack that is present
      only in hosts and not in routers



   b. Identify one layer that is present in BOTH hosts and routers.




2. Two things that a protocol can do to earn the term "unreliable"
   are (1) deliver packets with bits that have been inverted and
   (2) drop or lose packets entire packets.  Identify two others:

   a.



   b.



3. From the perspective of building a correct implementation of a
   protocol, the simplest and easiest type of service to provide is:

   a. reliable connection oriented      b. unreliable connection oriented

   c. reliable connection less          d. unreliable connection less


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


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

 5. In the Linux implementation of TCP/IP the "protocol family" sublayer
    is part of which layer:

    a. application                    b. transport

    c. network                        d. link




 6. What bandwidth in Hz is required to support a bit rate of 64,000 BPS
    that uses four distinct signalling states?






 7. How many signaling states are needed to achieve a bit rate
    of 40000 bits / second while signalling at a rate of 4000 baud









8. Suppose a channel passes harmonics in the range 20Khz - 30Khz.
   In decribing bandwidth and bit rates "K" always represents 10^3
   and not 2^10) What is the minimum useful duration (in seconds)
   for signalling states.





9. Do protocols (as the term is normally used in networking, e.g
   in SDLC, TCP, or IP) define the rules under which a layer communicates

   a. With the layer above it   b. With a peer layer in another node.


   c. With the layer below it.  d. All of the above.

10. Protocol headers used by a layer N are handled by layer K where
    K is closer to the Physical layer than 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.


11. For each of the following layers answer (E) if the layer has only
    endpoint-to-endpoint interoperability issues (P) if the layer has
    only point-to-point interoperability issues and (G) if the layer
    has global interoperability issues

   ___ a. Transport


   ___ b. Data link


   ___ c. Network