CS 640 - Final Exam - Fall 1994

Questions 1-35 (True or False). For all others fill in the blanks. 
Each question = 2 points.
 
The following refer to 802.5
1. A station that receives a frame can remove it from the ring if the restricted 
token is being used.
2. Retransmission is an option that can be set by the system manager.
3. The MAC protocol provides a fair service to all stations.
4. Any station can become the active monitor.
5. There can be two frame fragments on the ring at the same time.

The following refer to 802.3
6. A station does not have to wait more than k slot times to transmit, where k is 
derived from the number of stations attached to the bus.
7. If the bandwidth (in the standard) were decreased, the minimum frame size 
would  increase.
8. A sending station retransmits immediately after it detects a collision.
9. Ethernet and 802.3 differ by one field in the header.
10. Every station that senses a collision, sends a jam signal.

The following refer to FDDI
11. The receiving station removes the frame from the ring.
12. At most two frames can be on the ring at any time.
13. Synchronous traffic cannot be sent by a station if the Late_Count (LC) is greater 
than one when it receives the token.
14. Asynchronous traffic can only be sent by a station if the Late_Count (LC) is 
zero when the token arrives.

The following  refer to BGP
15. BGP uses SPF to determine optimal routes.
16. A BGP speaker can use source routing to control the route of packets a destination.
17. A BGP speaker can only advertise to its peers those routes that it itself uses.

The following may be included in a BGP update: 
18. Routes that have been withdrawn by the sender.
19. Alternate routes for a destination autonomous system.

The following refer to OSPF
20. Link state updates are transferred using a reliable protocol.
21. There may be multiple equal cost routes from a source to a destination.
22. OSPF routes IP datagrams between autonomous systems.

The following refer to ATM
23, ATM guarantees that no cells will be lost.
24. Switched virtual circuits differ from permanent virtual circuits in that cells 
may not arrive in the order in which they were sent.
25. The convergence sublayer for AAL5 adds a CRC and other information in a header.
26. AAL1 is designed to support constant bit rate video traffic.
27. When IP is used above ATM,  some ATM cells may have total length less than 53 bytes.
28. The ATM header checksum ensures that cell corruption can be detected.

The following refer to 802.2
29. The  protocol provides either a connection-oriented or a connectionless service 
interface.
30. A field in the  header specifies the upper (network) layer protocol.

31. Buffer reservation is required for virtual circuits but not for datagrams.
32. The link layer manages buffer allocation and de-allocation for the network layer.
33. To prevent data corruption, a checksum is used on the whole IP frame.
34. An IP datagram is always fragmented into smaller frames when it reaches a network 
which does not support a large frame.
35. An ICMP message will be sent whenever there are errors in the processing of datagrams.

OSPF recalculates routes when there are changes in the network's  ____ (36) but not 
when there are changes in the network's ____ (37).

OSPF runs over  the ______ (38) protocol  while BGP runs over the _______ (39) protocol.

OSPF areas are connected by the AS's ____ (40). 

Hold down and split horizon are methods used with ____ (41) routing protocols.

With CQL, buffers can be completely allocated to or shared between  _____ (42).

CQL prevents  _____ (43) deadlock but is susceptible to  _____ (44) deadlock.  

In SBP, buffers are allocated to  _____ (45).

Hop level deadlocks are prevented when using virtual circuits by  _____  (46),

The essential condition for deadlock to occur is _____ (47).

One of the flow control features that is available in virtual circuits but not in 
datagrams is _______ (48).

(49) Organization X has a class B address of 128.106. If organization X has 18 
different departments and each department would like to have its own network, then how 
many bits should the subnet mask have? 

Class B and Class C IP Internet Addresses were introduced because  _____ (50). 

There are ____ (51) possible class B  and ____ (52) possible class A IP networks.

The Internet Ping feature is supported by the ICMP ____ (53) type.

If an IP datagram fragment does not arrive at the destination, then the rest of the 
datagram is ____ (54).

X.25 Level 3 provides its users with a ____ (55) service interface.