Computer  Science 881
                         Quiz B           Name _______________________

 1. As described in class the sequence number wrap problem in the
    LFN domain is more of a problem:

    a. Because sequence numbers     b. Because the high rate at which
       can quickly wrap within         sequence numbers are consumed
       a given connection.             make it likely that a delayed
                                       duplicate from an old connection
                                       will be accepted.
    c. Both situations are equally
       problematic

 2. The sequence number wrapping problem can occur:

    a. Any time a very large window b. Any time a very high transmission
       is used regardless of the       rate is used regardless of the window
       transmission rate.              size

    c. Only when high transmission
       rates and large window sizes
       are used together.

 3. Large window sizes are needed

    a. Anytime Gigabyte transmission b. Any time propagation delays are
       speeds are used.                 > 100 ms.

    b. Only when the product of the
       trasmission rate and the
       propagation delay is large.


 4. For PAWS to work correctly

    a. The time between clock ticks  b. The time between clock ticks
       be smaller than the seq #        be larger than the seq #
       wrap time.                       wrap time.

    c. Both situations a and b       d. Neither situation a nor b
       provide protection.              provides protection.

 5. The maximum possible window size allowed in tcp by the window
    scale factor is:

    a. 2^16 bytes                    b. 2^20 bytes

    c. 2^30 bytes                    d. 2^32 bytes

6. a. Suppose the TCP timestamp option is in use and segments
      768 is received.  The receiver witholds his ACK until segment
      1024 is received.  Should the ack carry the timestamp from
      768 or 1024?


   b. Suppose segment 1280 is then lost and segment 1536 arrives.
      Should the duplicate ACK carry the timestamp from 768, 1024
      or 1536?


   c. Suppose segment 1280 wasn't lost after all but just delivered
      out of order.  It arrives shortly after 1536.  Should the
      new ACK carry the timestamp form 768,1024, 1280, or 1536?



7. SNMP data is exchanged using:

   a. Raw IP datagrams                b. A special protocol like ICMP

   c. UDP datagrams.                  d. TCP connections

8. a. The formal language used to define the mib goes by a three
      letter abbreviation followed by a numeral.. What is it?



   b. The rules used to encode MIB elements into SNMP packets are
      also known by a 3 letter abbreviation. What is it?



9. There are three main classes of SNMP messages. One is Trap.
   One is Get/GetNext/Request/Response. What is the third??




10. SNMP-1 provides a weak authentication scheme.  What is the
    term used for the "password".