Deck 19: Routing

Question 1

With fixed routing there is no difference between routing for da and virtual circuits.

Answer 1

True

Question 2

The simplest criterion in the selection of a route is to choose the _______.

A)network resources
B)maximum hop route
C)minimum hop route
D)maximum nodes available

Answer 2

C

Question 3

Fairness is a requirement for a routing function.

Answer 3

True

Question 4

The designer who seeks robustness does not need to cope with the requirement for stability.

Question 5

One of the easiest design aspects of switched data networks is routing.

Question 6

Because the least-cost criterion is more flexible,it is more common than the minimum-hop criterion.

Question 7

If the ________ has to do with the ability of the network to deliver packets via some route in the face of localized failures and overloads.

A)Correctness
B)Robustness
C)Efficiency
D)Optimality

Question 8

Due to the large amounts of bandwidth available on modem networks,processing and transmission overhead is a management issue and does not impair network efficiency.

Question 9

Generally there is only one possible route connecting a source to a destination.

Question 10

A key design issue in switched networks is routing.

Question 11

Random routing requires the use of network information.

Question 12

ARPANET is a packet switching network that was the foundation of the present day Internet.

Question 13

The selection of a route is generally based on some performance criterion.

Question 14

The ________ function attempts to find the least cost route through the network.

A)ABR
B)management
C)generic flow control
D)routing

Question 15

When the internal operation of the network is ________,a routing decision is made individually for each packet.

A)datagram
B)robust
C)internal virtual circuit
D)virtual circuit

Question 16

A property of flooding is all nodes that are directly or indirectly connected to the source node are visited.

Question 17

________ is determined by whether the routing decision is made on a packet or virtual circuit basis.

A)Place
B)Update timing
C)Decision time
D)VCC

Question 18

Adaptive routing algorithms typically rely on the exchange of information about traffic conditions among nodes.

Question 19

A variety of routing algorithms have been developed for packet- switching,frame relay and ATM networks.

Question 20

In virtually all packet-switching networks some sort of adaptive routing technique is used.

Question 21

The principle conditions that influence routing decisions are ________.

A)complexity and node malfunctions
B)failure and congestion
C)overhead and bandwidth
D)route distance and amount of nodes

Question 22

For ________,a single,permanent route is configured for each source-destination pair of nodes in the network.The routes only change when there is a change in the topology of the network.

Question 23

Which of the following is a drawback associated with adaptive routing?

A)It may react too quickly,causing congestion producing oscillation, or too slowly,being irrelevant.
B)All nodes that are directly or indirectly connected to the source node are visited.
C)Because all routes are tried,at least one copy of the packet to arrive at the destination will have used a minimum hop route.
D)Queue is an artificial measure of delay.

Question 24

In a ________ network,each node will remember the routing decision that was made when the virtual circuit was established,and simply pass on the packets without making a new decision.

Question 25

Which of the following is NOT a disadvantage of the first generation routing algorithm?

A)It responded slowly to congestion and delay increases and was not very accurate.
B)When a node or link fails,it can no longer be used as part of a route.
C)Queue length is an artificial measure of delay because some variable amount of processing time elapses between the arrival of
A packet at a node and its placement in an outbound queue.
D)The algorithm did not consider line speed,merely queue length.

Question 26

The ________ function seeks to design routes through the network for individual pairs of communicating end nodes so that the network is used efficiently.

Question 27

With ________,a packet is sent by a source node to every one of its neighbors.At each node,an incoming packet is retransmitted on all outgoing links except for the link on which it arrived.

Question 28

________ schemes can be categorized based on a number of factors,such as: what criterion is used to determine the best route between two nodes,what strategy is used for obtaining information needed to determine route,and whether a distributed or centralized algorithm is used.

Question 29

The primary function of a ________ network is to accept packets from a source station and deliver them to a destination station.

Question 30

With ________ the link costs used in designing routes cannot be based on any dynamic variable such as traffic.

A)fixed routing
B)random routing
C)adaptive routing
D)flooding

Question 31

The term ________ refers to which node or nodes in the network are responsible for the routing decision.

Question 32

"Because all routes are tried,at least one copy of the packet to arrive at the destination will have used a minimum-hop route" is a property of

A)fixed routing
B)flooding
C)adaptive routing
D)random routing

Question 33

"Given a network of nodes connected by bidirectional links,where each link has a cost associated with it in each direction,define the cost of a path between two nodes as the sum of the costs of the links traversed. For each pair of nodes,find a path with the lowest cost" is a description of ________.

A)least cost routing
B)random routing
C)fixed routing
D)alternate routing

Question 34

With ________ the routing decision is made by the source station,rather than by a network node,and is then communicated to the network.This allows the user to dictate a route through the network that meets criteria local to that user.

A)source routing
B)customer routing
C)user routing
D)station routing

Question 35

In the case of ________ the central node typically makes use of information obtained from all nodes.

A)NIS-UT
B)flooding
C)distributed routing
D)centralized routing

Question 36

For internal ________ operation a routing decision is made at the time the virtual circuit is established.

Question 37

A generalization of the minimum-hop criterion is ________ routing.

Question 38

Each node having the responsibility of selecting an output link for routing packets as they arrive is ________ routing.

Question 39

With ________,routing decisions that are made change as conditions on the network change.

A)fixed routing
B)flooding
C)adaptive routing
D)random routing

Question 40

The disadvantage of fixed routing is ________.

A)its lack of flexibility
B)its simplicity
C)it does not work with virtual circuits
D)it does not work with datagrams

Question 41

The ________ algorithm can be stated as follows: "Find the shortest paths from a given source node subject to the constraint that the paths contain at most one link,then find the shortest paths with a constraint of paths of at most two links, and so on."

Question 42

The routing decision is more complex,therefore,the processing burden on network nodes increases with ________ routing.

Question 43

The original routing algorithm,designed in 1969,was a distributed adaptive algorithm using estimated delay as the performance criterion and a version of the ________ algorithm.

Question 44

The second generation routing algorithm recomputes its routing table using________ algorithm when new information arrives.

Question 45

With ________,a node selects only one outgoing path for retransmission of an incoming packet.The outgoing link is chosen at random,excluding the link on which the packet arrived.If all links are equally likely to be chosen,then a node may simply utilize outgoing links in a round robin fashion.