Computer Science 825
                         Quiz C           Name _______________________

1. Recall that ATM Cells carry 48 data bytes and that the data rate
   required for voice is 64KB/sec. Suppose the telephone company
   decided to offer 100 MBit / Second service to your home at a cost
   of $10 per Giga-cell (no monthly minimum required).

   a. How much would a 20 minute long distance phone call cost.





   b. Now suppose you NFS mount a disk on your friend's computer
      in California and in the course of a few hours work transfer
      16,000,000 MB of data. How much does that cost?





   c. Finally, suppose you want to watch a movie over the same system.
      Screen resolution is 480 x 640 pixels.  Each pixel requires
      3 bytes and frame rate is 40 frames / second.  Suppose you
      can get 10 to 1 compression of the video stream. How much
      will a two hour movie cost?




2. Which routing algorithm is used by the spanning tree bridge
   if the location of the destination node is unknown?

   a. Spanning tree.              b. Flooding

   c. Backward learning.          d. Shortest past first.

3. Which routing algorithm does the spanning tree bridge employ
   to avoid having destination unknown occur very often?

   a. Spanning tree.              b. Flooding

   c. Backward learning.          d. Shortest past first.

4. Since a spanning tree is computed every few seconds why do
   destination unknown situations EVER occur after the spanning
   tree has been constructed for the first time?





5. Which routing algorithm is used by the source routing bridge
   in routing "discovery" packets to the destination.

   a. Spanning tree.              b. Flooding

   c. Backward learning.          d. Shortest past first.


6. Identify the network layer at which each of the following
   interconnects is used (in the terminology of the text).

   a. Bridge


   b. Repeater


7. The LAN architecture in which intra-architecture bridging has the
   LEAST number of complicating factors is:

   a. 802.3 to 802.3              b. 802.4 to 802.4

   c. 802.5 to 802.5              d. All are equally complicated.

8. Identify one complicating factor in bridging 802.5 to 802.5




9. Suppose the following is a diagram of an SNA network:

     A       D
   /   \   /   \
  Z      C      F
   \   /   \   /
     B       E

    Answer the following T or F.

    ___ a. Nodes B and C can't both have explicit routes with the
           identity (3, F).

    ___ b. For node A to have a functional explicit route with
           identity (3, F), node C must also have an explicit route
           with identity (3, F).

    ___ c. Nodes A and B can't both have explicit routes with the
           identity (3, F) where A's (3,F) passes through D and
           C's (3, F) passes through E.

    ___ d. Nodes A and B can both have explicit routes to F with A's
           called (3, F) and B's called (4, F) where A's (3,F) passes
           through D and B's (4, F) passes through E.