Computer  Science 881
                        Quiz 6  -     Name ________________________

1. Which of the following is NOT a reason put forth by telephone
   companies to convince you that it is not possible to do multimedia
   teleconferencing over IP.

   a. Connectionless transports can't   b. IP's occasional packet loss
      reserve bandwidth and thus           is fatal for audio conferencing
      can't guarantee service levels.

   c. Even when throughput is adequate
      IP's high response time variance
      make its use unsuitable.

2. Which of the following is NOT a reason put forth by IP bigots
   to convince you that it is not possible to do multimedia
   teleconferencing over the telephone.

   a. Its generally hard to join a    b.The number of required connections
      conference call already in        scales as N^2 where N is the
      progress.                         number of participants.

   c. The bit error rates of ATM/
      Sonet links are too high.

3. When a process wishes to receive multicast traffic it must JOIN
   a multicast group. It joins a group by:

   a. Binding its socket to the       b. Binding its socket to the Port
      group IP address of the            address being used by the
      multicast.                         multicast.

   c. By calling setsockopt with
      the IP_ADDMEMBERSHIP option

4. What are the two elements of the structure passed to setsockopt
   when IP_ADDMEMBERSHIP is requested.


   a.


   b.

5. For a process to be able to receive a particular multicast the
   process must know:

   a. the group IP address of the     b. the port number being used by the
      multicast.                         multicast.

   c. Both a. and b.                  d. Neither a. nor b.


6. The number of possible IP multicast addresses PER ethernet hardware
   level multicast address is closest to:

   a. 1 / 32                          b. 5

   c. 2^ 20                           d. 32


7. How does use of the ethernet multicast addresses as opposed to
   simply ethernet broadcasting of all multicast traffic affect the
   number of packets:

   ___ a. sent over the ethernet         1. Reduces

   ___ b. handled by the link driver     2. No effect

   ___ c. handled by receiving IP        3. Increases
          layer.

(Assume ALL hosts have SOME multicast traffic, but that all hosts
 don't listen to the SAME multicast.. )


8. For multicast to be able to work correctly, a protocol like IGMP
   is needed on:

   a. A single isolated ethernet     b. Two distinct networks connected
                                        by an IGMP capable router.

   c. An isoloated host.             d. All of the above.


9. When an IGMP query membership is sent to all hosts, only
   a single reply may have to be transmitted per group... even
   when the group has a large number of members.  Explain
   PRECISELY how this can be accomplished.






10. What is the primary advantage of the use of IGMP query as
    opposed to keeping track of membership based on "Exit group"
    messages generated by a host when its last member leaves
    a group.







11. The primary name server for a given zone acquires the name
    data describing the systems within its zone of responsibility:

    a. From an Ascii file maintained     b. Dynamically from each host
       within the zone by a sys admin.      system within the zone.

    c. By a zone transfer from the root  d. From a database maintained
       name server for the domain.          by the internic.