SSD8-1
.doc
Correct answer is (c)
Your score on this question is: 0.00
Feedback:
See section 1.2.4 of the course notes.
(b) This is expensive and is not necessary because each computer never uses more than the capacity of a 10 Mbps network.
1.
A router is installed to interconnect 4 subnetworks with MTUs of 1024, 2048, 576, and 1556 bytes respectively. Nodes A and B are connected to the first and second subnets respectively. An application on node A sends a 4096 byte datagram (e.g. using UDP) to an application on node B. How many incoming IP headers will the router process that have the MF (more fragments) flag set?
(a) 5
(b) 0
(c) 4
(d) 1
Correct answer is (c)
Your score on this question is: 0.00
Feedback:
See section 1.3.4 of the course notes.
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2.
In contrast to the Address Resolution Protocol (ARP), the Domain Name System (DNS)
(a) is not used to find hosts within a LAN
(b) is not used to find host addresses
(c) can use the same algorithm on all physical network technologies
(d) caches values
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.5 of the course notes.
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3.
Which of the following is the most credible threat to the continuing success of the Internet Protocol (IP) as currently deployed?
(a) Router memory will become insufficient to keep track of an exponentially increasing number of circuits.
(b) Big multimedia files will no longer fit into IP datagrams.
(c) Widespread deployment of fiber optics will call for more than 8192 fragments per datagram.
(d) The IP address space will be exhausted.
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.3.3 of the course notes.
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4.
At which of the following layers of the OSI protocol stack can the Internet Control Message Protocol be implemented?
Network
Transport
Data link
(a) II only
(b) I only
(c) III only
(d) I or II only
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.6 of the course notes.
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5.
After coming back from a vacation, you are eager to read your mail. You have several email accounts. One of them is served from hotmail.com, so you open up your browser and try to go to www.hotmail.com. Unfortunately, www.hotmail.com is down at the moment.
Because of this, which of the following packet types have traversed your ISP's router?
ARP
DNS
IP
(a) II only
(b) none
(c) II and III only
(d) I, II, and III
Correct answer is (c)
Your score on this question is: 0.00
Feedback:
See section 1.3.5 of the course notes.
(a) DNS is transported by IP.
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6.
Which of the following routing algorithms is the most scalable?
(a) Flooding
(b) Link state routing
(c) Distance vector routing
(d) Datagram broadcast
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.2 of the course notes.
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7.
A modification is proposed to the IP protocol that would eliminate the "Identification" and "Fragment Offset" fields from the IP header. This could result in nearly a 15% improvement in the throughput of a link used for short transactions. Which other effects would this proposal have?
The resulting internetwork would no longer be able to interconnect subnetworks of any kind.
The scalability of the routing protocol would improve.
Data delivery would be more robust in the presence of congestion.
(a) I only
(b) I and II only
(c) none
(d) III only
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 1.3.4 of the course notes.
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8.
A router is installed to interconnect 4 subnetworks with MTUs of 1024, 2048, 576, and 1556 bytes respectively. Nodes A and B are connected to the first and second subnets, respectively. An application on node A sends a 4096-byte datagram (e.g., using UDP) to an application on node B. How many IP fragments will the router process as a result?
(a) 2
(b) 1
(c) 4
(d) 5
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.3.4 of the course notes.
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9.
The Internet Protocol (IP)
is the only network-layer protocol
is required of hosts on the Internet
is the body of standard protocols in use on the Internet
(a) I only
(b) II only
(c) II and III only
(d) I and II only
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.1 of the course notes.
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10.
You have just connected a newly purchased computer to your LAN. Eagerly, you boot it for the first time and find with great disappointment that the machine will not be able to use the network because of an IP address conflict. How did the computer find the conflict?
(a) It sent an Ethernet frame to its own Ethernet address, and some other machine responded.
(b) It sent an IP packet to its own IP address and did not receive any IP packets within a timeout period.
(c) It sent a packet to 127.0.0.0 and did not receive any replies.
(d) It sent an ARP packet to the local broadcast address and received a reply.
Correct answer is (d)
Your score on this question is: 0.00
Feedback:
See section 1.3.5 of the course notes.
(a) Ethernet addresses are unique
1.
Which of the following developments will be facilitated by the widespread deployment of IPv6?
Every appliance can become an Internet node
Doubling in reliability of data links between routers
Elimination of IP address "spoofing" (a line of computer attack in which IP datagrams are made to appear to come from a bogus address)
(a) III only
(b) II and III only
(c) I, II, and III
(d) I only
Correct answer is (d)
Your score on this question is: 0.00
Feedback:
See section 1.3.8 of the course notes.
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2.
Which of the following is the most credible threat to the continuing success of the Internet Protocol (IP) as currently deployed?
(a) Widespread deployment of fiber optics will call for more than 8192 fragments per datagram.
(b) The IP address space will be exhausted.
(c) Big multimedia files will no longer fit into IP datagrams.
(d) Router memory will become insufficient to keep track of an exponentially increasing number of circuits.
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.3 of the course notes.
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3.
Which of the following benefit from "tunneling" IP datagrams by conveying them inside other packets?
Mobile IP
Multicast
Roll-out of IPv6
(a) I and III only
(b) I, II and III
(c) II only
(d) none
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.8 of the course notes.
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4.
A difference between routers and switches is that
(a) switches hold IP routing tables only for only local subnets
(b) switches connect only to hosts, whereas routers connect networks
(c) routers parse, process, and modify IP headers
(d) routers perform the same function as switches but the two are marketed in very different ways
Correct answer is (c)
Your score on this question is: 0.00
Feedback:
See section 1.3.2 of the course notes.
(a) Switches operate at the data link layer and have no "awareness" of the IP protocol.
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5.
The network interface card of a Web server that you manage has developed sporadic problems. You measure the packet loss rate from your desktop computer and immediately decide to replace the network card. After this simple operation, the Web server successfully rejoins the network, as confirmed by your officemate using her desktop computer. You eagerly go to your desktop to measure the improvement, but find instead that the Web server is not responding to any of your packets. What is your diagnosis?
(a) The new network card does not work.
(b) The Domain Name System (DNS) has not yet updated its entry for the Web server.
(c) Your desktop computer's network card does not work.
(d) Your desktop computer is still trying to contact the server's old network card.
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.3.5 of the course notes.
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6.
The following Java declaration
InetAddress addr = InetAddress.getbyName("www.example.com");
will fail when
(a) a route to www.example.com is not available
(b) www.example.com does not respond to ARP requests
(c) all known DNS servers are down
(d) www.example.com is down
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See Chapter 10 of the yellow book. See section 1.3.5 of the course notes.
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7.
At which of the following layers of the OSI protocol stack can the Internet Control Message Protocol be implemented?
Network
Transport
Data link
(a) I or II only
(b) I only
(c) II only
(d) III only
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.6 of the course notes.
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8.
A modification is proposed to the IP protocol that would eliminate the "Identification" and "Fragment Offset" fields from the IP header. This could result in nearly a 15% improvement in the throughput of a link used for short transactions. Which other effects would this proposal have?
The resulting internetwork would no longer be able to interconnect subnetworks of any kind.
The scalability of the routing protocol would improve.
Data delivery would be more robust in the presence of congestion.
(a) I and II only
(b) I only
(c) III only
(d) none
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.4 of the course notes.
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9.
A network uses a routing algorithm that uses paths with the least number of hops. These paths are computed periodically using a shortest-path algorithm. In this network, datagrams
are routed around congested links
may traverse the same router twice
will always reach their destination
(a) I and II only
(b) none
(c) III only
(d) I and III only
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.2 of the course notes.
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10.
The Dynamic Host Configuration Protocol (DHCP) may be used to
configure the scheduling policy of a busy server
relieve the saturation of the IP address space
assign a fixed address to a Web server after a reboot
(a) III only
(b) II only
(c) I only
(d) II and III only
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.3.6 of the course notes.
1.
The main network engineer of a large corporation is charged with designing and deploying the company's intranet. She has decided to use a connection-oriented network layer. Which of the following concerns do you think motivated her choice?
(a) Cost of the routers as the network grows
(b) Ability to re-route traffic around congested links
(c) Cost of short transactions—e.g., credit card charge approval.
(d) Ability to reserve bandwidth—e.g., for important presentations to the Board
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.3.1 of the course notes.
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2.
The Internet Protocol (IP) is used in the network layer of the Internet. Which service does IP provide to the transport layer?
(a) Connection-oriented service via virtual circuits
(b) Connectionless service via virtual circuits
(c) Connection-oriented service via datagrams
(d) Connectionless service via datagrams
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.3.1 of the course notes.
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3.
You have just connected a newly purchased computer to your LAN. Eagerly, you boot it for the first time and find with great disappointment that the machine will not be able to use the network because of an IP address conflict. How did the computer find the conflict?
(a) It sent a packet to 127.0.0.0 and did not receive any replies.
(b) It sent an ARP packet to the local broadcast address and received a reply.
(c) It sent an IP packet to its own IP address and did not receive any IP packets within a timeout period.
(d) It sent an Ethernet frame to its own Ethernet address, and some other machine responded.
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.5 of the course notes.
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4.
The class B IP network 128.2.x.x has been assigned to Carnegie Mellon University. To relieve congestion in its internal LAN, Carnegie Mellon has decided to subnet this IP network. This will have which of the following consequences?
The configuration of the subnets will have to be announced to routers all over the world by notifying NIC and/or IANA.
A computer may need to change its IP address when moved from one office to another.
Some bridges, hubs, or switches will need to be replaced with routers.
(a) III only
(b) I, II, and III
(c) II and III only
(d) I and III only
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.3 of the course notes.
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5.
Using the Domain Name System, we can find
that 204.194.30.130 is the IP address of www.example.com
that ns.watson.ibm.com knows how to handle email for all IBM employees
that a datagram for an IBM address in India will be routed through an Internet IBM router named ibm-gw.customer.ibm.net in New York
(a) I and II only
(b) II and III only
(c) I only
(d) I, II, and III
Correct answer is (a)
Your score on this question is: 0.00
Feedback:
See section 1.3.5 of the course notes.
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6.
Which of the following protocols are essential to the existence of the Traceroute tool?
IP
ICMP
TCP
(a) I and II only
(b) II and III only
(c) II only
(d) I only
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 1.3.7 of the course notes.
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7.
Which of the following benefit from "tunneling" IP datagrams by conveying them inside other packets?
Mobile IP
Multicast
Roll-out of IPv6
(a) none
(b) I, II and III
(c) I and III only
(d) II only
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.8 of the course notes.
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8.
The following Java declaration
InetAddress addr = InetAddress.getbyName("www.example.com");
will fail when
(a) www.example.com does not respond to ARP requests
(b) www.example.com is down
(c) all known DNS servers are down
(d) a route to www.example.com is not available
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See Chapter 10 of the yellow book. See section 1.3.5 of the course notes.
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9.
A corporate information systems manager is interested in collecting statistics on the frequency of computer failures within the organization. Most failures result in an automatic reboot, so the failed computer is typically back on the network in less than a minute. The corporate network connects 1,500 computers in far-flung locations to which the average latency of a packet is 40 milliseconds. The manager asks you to write a tool that will collect the times at which failures occurred in which computers. She wants it by tomorrow, so the tool will have to be simple. On which protocol will you base your implementation?
(a) ICMP (ping)
(b) PLM
(c) SNMP
(d) TCP
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.6 of the course notes.
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10.
Which of the following is the most credible threat to the continuing success of the Internet Protocol (IP) as currently deployed?
(a) Big multimedia files will no longer fit into IP datagrams.
(b) Widespread deployment of fiber optics will call for more than 8192 fragments per datagram.
(c) Router memory will become insufficient to keep track of an exponentially increasing number of circuits.
(d) The IP address space will be exhausted.
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.3.3 of the course notes.
1.
Which of the following protocols are essential to the existence of the Traceroute tool?
IP
ICMP
TCP
(a) II only
(b) I only
(c) I and II only
(d) II and III only
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.7 of the course notes.
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2.
Which of the following is the most credible threat to the continuing success of the Internet Protocol (IP) as currently deployed?
(a) Widespread deployment of fiber optics will call for more than 8192 fragments per datagram.
(b) Router memory will become insufficient to keep track of an exponentially increasing number of circuits.
(c) The IP address space will be exhausted.
(d) Big multimedia files will no longer fit into IP datagrams.
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.3 of the course notes.
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3.
The Dynamic Host Configuration Protocol (DHCP) may be used to
configure the scheduling policy of a busy server
relieve the saturation of the IP address space
assign a fixed address to a Web server after a reboot
(a) II and III only
(b) II only
(c) III only
(d) I only
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 1.3.6 of the course notes.
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4.
Tired of inaccurate routing tables, Joe, the network engineer, devises what he thinks is surely the best of all routing algorithms, which calculates the shortest-delay path for each packet. The algorithm works as follows. A routing server periodically polls each router for its full routing table and link delay statistics. This information from all routers is amalgamated into a complete model of the state of the network topology. Using this model, Joe's program selects the shortest delay paths, for which he derives new routing tables and sends to each router. Joe wants to deploy his algorithm immediately, but critics envious of his intelligence have offered the following objections. Which of the objections, if any, deserve attention?
Joe's algorithm is not scalable
Joe's algorithm is not reliable
Joe's algorithm results in inaccurate routing tables
(a) I and II only
(b) III only
(c) I, II, and III
(d) II only
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.2 of the course notes.
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5.
In contrast to the Address Resolution Protocol (ARP), the Domain Name System (DNS)
(a) can use the same algorithm on all physical network technologies
(b) is not used to find hosts within a LAN
(c) caches values
(d) is not used to find host addresses
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 1.3.5 of the course notes.
--------------------------------------------------------------------------------
6.
Which of the following developments will be facilitated by the widespread deployment of IPv6?
Every appliance can become an Internet node
Doubling in reliability of data links between routers
Elimination of IP address "spoofing" (a line of computer attack in which IP datagrams are made to appear to come from a bogus address)
(a) II and III only
(b) III only
(c) I only
(d) I, II, and III
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.8 of the course notes.
--------------------------------------------------------------------------------
7.
Using the Domain Name System, we can find
that 204.194.30.130 is the IP address of www.example.com
that ns.watson.ibm.com knows how to handle email for all IBM employees
that a datagram for an IBM address in India will be routed through an Internet IBM router named ibm-gw.customer.ibm.net in New York
(a) I, II, and III
(b) I and II only
(c) I only
(d) II and III only
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.5 of the course notes.
--------------------------------------------------------------------------------
8.
A network uses a routing algorithm that uses paths with the least number of hops. These paths are computed periodically using a shortest-path algorithm. In this network, datagrams
are routed around congested links
may traverse the same router twice
will always reach their destination
(a) I and II only
(b) III only
(c) I and III only
(d) none
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.3.2 of the course notes.
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9.
In a network that uses shortest-path-per-hop routing, router A receives a datagram destined for host H and determines that the shortest path to H traverses routers B, C, and D, in that order. The datagram may traverse
B and D, but not C
B, C, and D, in that order
C and D, but not B
(a) none
(b) I and II only
(c) I, II, and III
(d) II only
Correct answer is (b)
Your score on this question is: 0.00
Feedback:
See section 1.3.2 of the course notes.
(d) B may have a different shortest path to D, unbeknownst to A
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10.
A difference between routers and switches is that
(a) switches connect only to hosts, whereas routers connect networks
(b) switches hold IP routing tables only for only local subnets
(c) routers parse, process, and modify IP headers
(d) routers perform the same function as switches but the two are marketed in very different ways
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.2 of the course notes.
1.
In a network that uses shortest-path-per-hop routing, router A receives a datagram destined for host H and determines that the shortest path to H traverses routers B, C, and D, in that order. The datagram may traverse
B and D, but not C
B, C, and D, in that order
C and D, but not B
(a) II only
(b) I and II only
(c) none
(d) I, II, and III
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.2 of the course notes.
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2.
A router is installed to interconnect 4 subnetworks with MTUs of 1024, 2048, 576, and 1556 bytes respectively. Nodes A and B are connected to the first and second subnets, respectively. An application on node A sends a 4096-byte datagram (e.g., using UDP) to an application on node B. How many IP fragments will the router process as a result?
(a) 4
(b) 1
(c) 5
(d) 2
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.4 of the course notes.
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3.
At which of the following layers of the OSI protocol stack can the Internet Control Message Protocol be implemented?
Network
Transport
Data link
(a) I or II only
(b) I only
(c) II only
(d) III only
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.6 of the course notes.
--------------------------------------------------------------------------------
4.
A corporate information systems manager is interested in collecting statistics on the frequency of computer failures within the organization. Most failures result in an automatic reboot, so the failed computer is typically back on the network in less than a minute. The corporate network connects 1,500 computers in far-flung locations to which the average latency of a packet is 40 milliseconds. The manager asks you to write a tool that will collect the times at which failures occurred in which computers. She wants it by tomorrow, so the tool will have to be simple. On which protocol will you base your implementation?
(a) SNMP
(b) PLM
(c) TCP
(d) ICMP (ping)
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 1.3.6 of the course notes.
--------------------------------------------------------------------------------
5.
The Dynamic Host Configuration Protocol (DHCP) may be used to
configure the scheduling policy of a busy server
relieve the saturation of the IP address space
assign a fixed address to a Web server after a reboot
(a) I only
(b) II and III only
(c) II only
(d) III only
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.6 of the course notes.
--------------------------------------------------------------------------------
6.
The Internet Protocol (IP)
is the only network-layer protocol
is required of hosts on the Internet
is the body of standard protocols in use on the Internet
(a) II and III only
(b) I and II only
(c) II only
(d) I only
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.1 of the course notes.
--------------------------------------------------------------------------------
7.
A modification is proposed to the IP protocol that would eliminate the "Identification" and "Fragment Offset" fields from the IP header. This could result in nearly a 15% improvement in the throughput of a link used for short transactions. Which other effects would this proposal have?
The resulting internetwork would no longer be able to interconnect subnetworks of any kind.
The scalability of the routing protocol would improve.
Data delivery would be more robust in the presence of congestion.
(a) III only
(b) I only
(c) I and II only
(d) none
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.3.4 of the course notes.
--------------------------------------------------------------------------------
8.
The Internet Protocol (IP) is used in the network layer of the Internet. Which service does IP provide to the transport layer?
(a) Connectionless service via datagrams
(b) Connection-oriented service via virtual circuits
(c) Connectionless service via virtual circuits
(d) Connection-oriented service via datagrams
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 1.3.1 of the course notes.
--------------------------------------------------------------------------------
9.
Which of the following routing algorithms is the most scalable?
(a) Link state routing
(b) Datagram broadcast
(c) Distance vector routing
(d) Flooding
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 1.3.2 of the course notes.
--------------------------------------------------------------------------------
10.
A router is installed to interconnect 4 subnetworks with MTUs of 1024, 2048, 576, and 1556 bytes respectively. Nodes A and B are connected to the first and second subnets respectively. An application on node A sends a 4096 byte datagram (e.g. using UDP) to an application on node B. How many incoming IP headers will the router process that have the MF (more fragments) flag set?
(a) 5
(b) 4
(c) 0
(d) 1
Correct answer is (b)
Your score on this question is: 0.00
Feedback:
See section 1.3.4 of the course notes.
1.
Collision Detection improves the throughput of multiple access networks because
it can shorten the length of garbled frames
it can decrease the number of garbled frames
it delays by a random amount of time when a collision is detected
(a) I only
(b) II and III only
(c) I, II, and III
(d) I and II only
Correct answer is (d)
Your score on this question is: 0.00
Feedback:
See section 1.2.4 of the course notes.
(c) Choice III is true regardless of whether or not collision detection is used.
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2.
What is the type of an "8+1" parity code that outputs 100101011?
(a) Even Parity
(b) Cannot tell since we do not know which bit is the parity bit
(c) Null Parity
(d) Odd Parity
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.2.2 of the course notes.
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3.
When the data link layer applies "framing" to the data to be transmitted, it
(a) enhances it with extra data that permits the receiver to synchronize with the sender
(b) inserts flags to draw attention to high-priority data within a transmission
(c) cuts out the headers from higher layer protocols before transmission
(d) adds the protocol headers from higher layers to the data before it transmits it
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 1.2.2 of the course notes.
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4.
A cable is rated at 19200 baud. A 19200 baud cable is guaranteed to transmit a signal successfully that has the potential to change 19200 times per second. The maximum throughput of this cable, assuming a sensible encoding,
(a) can be any number greater than or equal to 19200 bits per second, depending on the way the data is encoded into signal voltages
(b) is between 19200 and 38400 bits per second, depending on the bit pattern of the transmitted data
(c) is exactly 19200 bits per second
(d) is less than 19200 bits per second
Correct answer is (a)
Your score on this question is: 0.00
Feedback:
See section 1.2.1 of the course notes.
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5.
A fiber optic is found to be able to deliver light cleanly in a frequency range 25,000 GHz wide. This fiber can be used to create the following type of channel between two routers
a single 50 terabits per second (Tbps = 1,000 Gbps) data channel
5 2-Gbps data channels
one video channel but no data channels, because data cannot be encoded in light beams
(a) I only
(b) I and II only
(c) III only
(d) II only
Correct answer is (d)
Your score on this question is: 0.00
Feedback:
See section 1.2.1 of the course notes.
(b) The electronics that interface to the fiber cannot process more than a few GHz of bandwidth in a single channel.
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6.
A packet-switched network uses switches that schedule packets using a first-in-first-out (FIFO) discipline. Several people want to carry out a conference over this network. The conference is carried out via typed text for the most part, but, occasionally, one of the parties has to send a large video. This happens very rarely. Which of the following switching approaches is most suitable for this application?
(a) Message-switched
(b) Space-switched
(c) Circuit-switched
(d) Packet-switched
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.2.3 of the course notes.
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7.
Which of the following are responsibilities of the data link layer?
Noticing transmission errors
Regulating transmission speed when a receiver is overwhelmed
Regulating transmission speed when any of several IP routers in a network path are overwhelmed
(a) I only
(b) I and II only
(c) I, II, and III
(d) II and III only
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.2.2 of the course notes.
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8.
A specific CSMA-CD network such as 10-BASET "Ethernet"
(a) can connect very distant nodes
(b) has higher cost per node as nodes are added
(c) suffers performance degradation as nodes are added
(d) works best for an even number of nodes
Correct answer is (c)
Your score on this question is: 0.00
Feedback:
See section 1.2.4 of the course notes.
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9.
A university has 20 computers in a laboratory that is currently served by several small 10 Base-T "Ethernet" hubs. The network performance has been found to be lacking, and an upgrade is planned. The computers usually have modest network needs (in the order of 500 Kbps), but one or two are occasionally used to receive high-quality remote video streams that require in the order of 10 Mbps. No more than two computers are used for this purpose at any given time, but any two may be used for this application. What would you suggest for the upgrade?
(a) Replace the hubs with 100 Base-T hubs
(b) Replace the hubs with 10 Base-T switches
(c) A 10 Base-T bridge to connect several existing hubs
(d) A new bank of dial-up modems
Correct answer is (a)
Your score on this question is: 0.00
Feedback:
See section 1.2.4 of the course notes.
(c) This will not provide enough bandwidth for the video application to any computer.
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10.
The point-to-point (PPP) protocol
can only be used in analog dial-up connections
is a data-link protocol
can only be used to carry IP over serial lines
(a) II only
(b) III only
(c) I and II only
(d) II and III only
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 1.2.5 of the course notes.
1.
If you have seen any mobile telephone antennas, you will have noticed that they have groups of radiating elements facing different directions. Most antennas we know are arranged in a triangle, so that each group spans a 120-degree arc of the horizon, but we have also seen squares in which each group spans a 90-degree arc instead. There is one such arrangement for each cell of a mobile phone system. This sort of base station is unsightly and expensive. A cell could instead use a single omnidirectional antenna that would be simple and inconspicuous. Why do you think the more complicated designs are used?
(a) To decrease frequency reuse without the need for time-division multiplexing
(b) To increase frequency reuse without having to build more antenna towers
(c) To decrease the number of times a call must be handed off from one base station to another.
(d) To allow the use of switches based on space-division multiplexing
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.2.6 of the course notes.
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2.
What is the type of an "8+1" parity code that outputs 100101011?
(a) Cannot tell since we do not know which bit is the parity bit
(b) Odd Parity
(c) Even Parity
(d) Null Parity
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 1.2.2 of the course notes.
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3.
A parity code is a(n)
(a) fair resource allocation scheme
(b) duplex transmission technique
(c) error-correcting code
(d) error-detecting code
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 1.2.2 of the course notes.
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4.
After the phone company installs a T1 trunk to an office building, which of the following can it provide to the tenants of the building? Recall that a T1 trunk has a capacity of 1.544 Mbps, and that a voice channel requires an isolated 3 KHz channel.