SSD8-1
.doc
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6.
A TCP implementation that uses a sliding window for flow control has a coding error that causes it to calculate a window size greater than the ideal. What are some of the likely effects of this error?
Unnecessarily idle network links
Unnecessary packet losses
Greater memory usage in routers
(a) I only
(b) II and III only
(c) II only
(d) I, II, and III
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 2.1.1 of the course notes.
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7.
A 4-port Internet router has been designed with enough buffer space and CPU power to service its four links at their maximum capacity. Which of the following is(are) sufficient to keep the router from becoming congested?
Neighboring routers are similarly designed.
All ports have comparable throughput and latency.
Links to other routers have neither interference nor any losses.
(a) I, II, and III
(b) II and III only
(c) none
(d) I and II only
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 2.1.4 of the course notes.
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8.
Computer A has just received a TCP segment with a header that has the values 1500 and 1501 in the ACK and sequence number fields, respectively, from computer B. From this, we know that computer B is waiting for sequence number
(a) 1500
(b) 1501
(c) 1499
(d) 1502
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 2.1.3 of the course notes.
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9.
As you access a remote Web site (as you are currently doing), a TCP segment is received from the Web server that advertises a receive window size of 20 Kbytes. From the round trip delay and recent history, your computer's TCP code decides to expand its congestion window to 15 Kbytes, in order to take advantage of an apparent improvement in network conditions. What TCP sending window size will be in effect in your computer at this point?
(a) 5 Kbytes
(b) 15 Kbytes
(c) 20 Kbytes
(d) 35 Kbytes
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 2.1.3 of the course notes.
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10.
In a network that is mostly used for HTTP (Web) traffic, which of the following is a reasonable approach to minimizing the amount of wasted bandwidth?
(a) Populate routers with more memory than they will ever need.
(b) Divide the available bandwidth equally among all connections.
(c) Have data sources increase their sending rate until congestion is detected.
(d) Have data sources send data as soon as it is available.
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 2.1.4 of the course notes.
1.
The Transmission Control Protocol (TCP) differs from the User Data Protocol (UDP) in that
TCP has lower overhead
TCP is a transport-layer protocol
TCP provides reliable transmission
(a) II only
(b) II and III only
(c) III only
(d) I and II only
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 2.1.3 of the course notes.
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2.
A 4-port Internet router has been designed with enough buffer space and CPU power to service its four links at their maximum capacity. Which of the following is(are) sufficient to keep the router from becoming congested?
Neighboring routers are similarly designed.
All ports have comparable throughput and latency.
Links to other routers have neither interference nor any losses.
(a) I, II, and III
(b) none
(c) I and II only
(d) II and III only
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 2.1.4 of the course notes.
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3.
Most postal systems allow customers to request a receipt notification, by which the Postal Service promises to notify the sender when the letter has been delivered to the recipient. This makes the postal system
a reliable network services provider
a reliable transport services provider
a datagram network service provider
(a) III only
(b) II only
(c) I and III only
(d) I only
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 2.1.1 of the course notes.
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4.
You are charged with setting up the technology required to transmit a video-conference over an IP-based internetwork. You will have to implement a sending and a receiving application. Where will you handle network congestion?
(a) In both the sending and receiving applications
(b) In neither the sending nor receiving application, because late-arriving video frames are of no use
(c) In the sending application only
(d) In neither the sending nor receiving application, because TCP takes care of it
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 2.1.5 of the course notes.
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5.
The load offered to a network is the aggregate data rate at which the hosts connected to it attempt to send data. When the offered load increases by 20%, the amount of data successfully transported
may decrease by more than 30%
may decrease by less than 30%
may increase by less than 30%
(a) III only
(b) I and II only
(c) II and III only
(d) I, II, and III
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 2.1.4 of the course notes.
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6.
To improve network performance, a TCP receiver sends some information back to the sender by piggybacking it onto the headers of packets sent from the receiver to the sender. Which of the following can be sent this way?
New retransmission timeout values
Number of the last TCP segment being acknowledged
Available receiver buffer size
(a) II and III only
(b) I only
(c) II only
(d) I and II only
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 2.1.3 of the course notes.
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7.
Because of a faulty routing table, a network provider is temporarily unable to successfully deliver packets from host B to host A, even though packets from A to B experience no problems. This malfunction lasts 15 minutes. At the time the malfunction occurred, the TCP entity at host A was sending a large file to host B. Which of the following is true of the packets that had not yet been sent to B?
(a) No packets will reach B.
(b) All packets will reach B at a degraded rate.
(c) Some packets will reach B, but most will not.
(d) All packets will reach B normally.
Correct answer is (c)
Your score on this question is: 10.00
Feedback:
See section 2.1.1 of the course notes.
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8.
What is the service that TCP provides but UDP does not?
(a) API provided to application layer
(b) Congestion control
(c) Error detection using checksum
(d) Addressing
Correct answer is (b)
Your score on this question is: 10.00
Feedback:
See section 2.1.3 of the course notes.
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9.
You have just written an implementation of a transport protocol. You have aggressively pursued performance. For example, all acknowledgments are piggybacked on top of regular data packets, in order to minimize their overhead. When your company releases your product, however, you get the following complaint:
(a) Many packets are retransmitted many times even though the network is idle.
(b) Packet headers have doubled in size, thereby halving the expected performance gains.
(c) ARP responses take a lot longer than before.
(d) Many more packets than before fail to reach the receiving host.
Correct answer is (a)
Your score on this question is: 10.00
Feedback:
See section 2.1.3 of the course notes.
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10.
Computer A has just received a TCP segment with a header that has the values 1500 and 1501 in the ACK and sequence number fields, respectively, from computer B. From this, we know that computer B is waiting for sequence number
(a) 1499
(b) 1500
(c) 1502
(d) 1501
Correct answer is (d)
Your score on this question is: 10.00
Feedback:
See section 2.1.3 of the course notes.
1.
A student's desktop system executes a procedure call to a departmental server. Which of the following are true?
A remote procedure call will always take longer than a local call to complete.
A remote procedure call will never take longer than a local call to complete.
A remote procedure call may fail when the same call executed locally would succeed.
(a) I only
(b) II and III only
(c) I and III only
(d) III only
Correct answer is (d)
Your score on this question is: 20.00
Feedback:
See section 2.2.3 of the course notes.
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2.
In RPC, the process of encoding parameters and results is called
(a) parameterizing
(b) packetizing
(c) RPCode
(d) marshaling
Correct answer is (d)
Your score on this question is: 20.00
Feedback:
See section 2.2.3 of the course notes.
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3.
A Web server is attending to five active requests from five computers. It receives data sent via TCP to
(a) 5 TCP ports
(b) 1 TCP port
(c) 6 TCP ports
(d) 2 TCP ports
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.2.1 of the course notes.
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4.
High-speed network interfaces for PCs or Macs are typically designed for use in the _____ bus.
(a) ISA
(b) PCMCIA
(c) PCI
(d) SCSI
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.2.6 of the course notes.
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5.
What C function converts long integers from machine-byte order to network-byte order?
(a) atoin
(b) htonl
(c) endian
(d) bcopy
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.2.2 of the course notes.
1.
High-speed network interfaces for PCs or Macs are typically designed for use in the _____ bus.
(a) ISA
(b) PCI
(c) SCSI
(d) PCMCIA
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.2.6 of the course notes.
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2.
In theory, the minimum RPC time on an Ethernet is 102 microseconds. In practice, getting the RPC time down to 1500 microseconds is a considerable achievement. What causes this difference?
(a) Ethernet has long delay time
(b) Large buffer on network interface card takes a while to fill up
(c) Operating system and protocol overhead
(d) Limited memory bandwidth between processor and network interface card
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.2.7 of the course notes.
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3.
A Web server is attending to five active requests from five different computers. How many sockets is this server using?
(a) 2
(b) 1
(c) 6
(d) 5
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
One socket is active to receive new requests, and five are active to transfer data. See section 2.2.1 of the course notes.
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4.
A Web server is attending to five active requests from five computers. It receives data sent via TCP to
(a) 6 TCP ports
(b) 2 TCP ports
(c) 1 TCP port
(d) 5 TCP ports
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.2.1 of the course notes.
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5.
Two machines are connected to each other with a 100 megabit/sec fiber connection. The round trip time between the machines is 80 milliseconds. What minimum size must the receive buffer be to allow the machines to utilize the full 100 megabits/sec?
(a) 1 megabyte
(b) 2 megabytes
(c) 500 kilobytes
(d) 8 megabytes
Correct answer is (a)
Your score on this question is: 20.00
Feedback:
See section 2.2.7 of the course notes.
1.
What C function converts long integers from machine-byte order to network-byte order?
(a) atoin
(b) endian
(c) htonl
(d) bcopy
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.2.2 of the course notes.
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2.
Which of the following statements are true?
You can buy more bandwidth, but buying lower delay is not always possible.
Network congestion is easier to recover from than to prevent.
The way to avoid extra work with timeouts is to set timers shorter than necessary.
(a) II 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 2.2.7 of the course notes.
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3.
A Web server is attending to five active requests from five different computers. How many sockets is this server using?
(a) 5
(b) 6
(c) 1
(d) 2
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
One socket is active to receive new requests, and five are active to transfer data. See section 2.2.1 of the course notes.
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4.
MIME
(a) is a library to convert between machine byte order and network byte order
(b) identifies the type of documents included in electronic mail messages
(c) allows users to access audio files from a text-only terminal
(d) is a way of conserving IP addresses
Correct answer is (b)
Your score on this question is: 0.00
Feedback:
See section 2.2.2 of the course notes.
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5.
The idea behind RPC is to
(a) provide a reliable byte stream transfer with congestion control
(b) make interactions with a server look like a local procedure call to the developer of the client
(c) provide fast, semi-reliable transfer of streaming media over the Internet
(d) enable network interface serial numbers to be tracked after leaving the factory
Correct answer is (b)
Your score on this question is: 0.00
Feedback:
See section 2.2.3 of the course notes.
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1.
Two machines are connected to each other with a 100 megabit/sec fiber connection. The round trip time between the machines is 80 milliseconds. What minimum size must the receive buffer be to allow the machines to utilize the full 100 megabits/sec?
(a) 500 kilobytes
(b) 2 megabytes
(c) 1 megabyte
(d) 8 megabytes
Correct answer is (c)
Your score on this question is: 0.00
Feedback:
See section 2.2.7 of the course notes.
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2.
A Web server is attending to five active requests from five different computers. How many sockets is this server using?
(a) 2
(b) 5
(c) 6
(d) 1
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
One socket is active to receive new requests, and five are active to transfer data. See section 2.2.1 of the course notes.
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3.
In RPC, the process of encoding parameters and results is called
(a) marshaling
(b) parameterizing
(c) RPCode
(d) packetizing
Correct answer is (a)
Your score on this question is: 20.00
Feedback:
See section 2.2.3 of the course notes.
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4.
Which of the following will help to avoid context switches in network code?
Run one server for each client.
Library procedures that send data should buffer until a substantial amount is ready to be sent.
Data that arrives should be passed to the user as soon as possible after it arrives.
(a) II only
(b) I and III only
(c) III only
(d) I and II only
Correct answer is (a)
Your score on this question is: 0.00
Feedback:
See section 2.2.7 of the course notes.
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5.
In theory, the minimum RPC time on an Ethernet is 102 microseconds. In practice, getting the RPC time down to 1500 microseconds is a considerable achievement. What causes this difference?
(a) Large buffer on network interface card takes a while to fill up
(b) Operating system and protocol overhead
(c) Ethernet has long delay time
(d) Limited memory bandwidth between processor and network interface card
Correct answer is (b)
Your score on this question is: 0.00
Feedback:
See section 2.2.7 of the course notes.
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1.
The network layer and standard transport protocols (TCP and UDP) are typically implemented inside the _____.
(a) operating system
(b) network device driver
(c) I/O bus
(d) processor
Correct answer is (a)
Your score on this question is: 20.00
Feedback:
See section 2.2.6 of the course notes.
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2.
In RPC, the process of encoding parameters and results is called
(a) marshaling
(b) packetizing
(c) parameterizing
(d) RPCode
Correct answer is (a)
Your score on this question is: 20.00
Feedback:
See section 2.2.3 of the course notes.
--------------------------------------------------------------------------------
3.
The idea behind RPC is to
(a) make interactions with a server look like a local procedure call to the developer of the client
(b) provide a reliable byte stream transfer with congestion control
(c) provide fast, semi-reliable transfer of streaming media over the Internet
(d) enable network interface serial numbers to be tracked after leaving the factory
Correct answer is (a)
Your score on this question is: 20.00
Feedback:
See section 2.2.3 of the course notes.
--------------------------------------------------------------------------------
4.
Two machines are connected to each other with a 100 megabit/sec fiber connection. The round trip time between the machines is 80 milliseconds. What minimum size must the receive buffer be to allow the machines to utilize the full 100 megabits/sec?
(a) 1 megabyte
(b) 8 megabytes
(c) 2 megabytes
(d) 500 kilobytes
Correct answer is (a)
Your score on this question is: 20.00
Feedback:
See section 2.2.7 of the course notes.
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5.
A Web server is attending to five active requests from five different computers. How many sockets is this server using?
(a) 1
(b) 5
(c) 2
(d) 6
Correct answer is (d)
Your score on this question is: 20.00
Feedback:
One socket is active to receive new requests, and five are active to transfer data. See section 2.2.1 of the course notes.
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1.
A student's desktop system executes a procedure call to a departmental server. Which of the following are true?
A remote procedure call will always take longer than a local call to complete.
A remote procedure call will never take longer than a local call to complete.
A remote procedure call may fail when the same call executed locally would succeed.
(a) I only
(b) II and III only
(c) I and III only
(d) III only
Correct answer is (d)
Your score on this question is: 20.00
Feedback:
See section 2.2.3 of the course notes.
--------------------------------------------------------------------------------
2.
In RPC, the process of encoding parameters and results is called
(a) parameterizing
(b) packetizing
(c) RPCode
(d) marshaling
Correct answer is (d)
Your score on this question is: 20.00
Feedback:
See section 2.2.3 of the course notes.
--------------------------------------------------------------------------------
3.
A Web server is attending to five active requests from five computers. It receives data sent via TCP to
(a) 5 TCP ports
(b) 1 TCP port
(c) 6 TCP ports
(d) 2 TCP ports
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.2.1 of the course notes.
--------------------------------------------------------------------------------
4.
High-speed network interfaces for PCs or Macs are typically designed for use in the _____ bus.
(a) ISA
(b) PCMCIA
(c) PCI
(d) SCSI
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.2.6 of the course notes.
--------------------------------------------------------------------------------
5.
What C function converts long integers from machine-byte order to network-byte order?
(a) atoin
(b) htonl
(c) endian
(d) bcopy
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.2.2 of the course notes.
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1.
High-speed network interfaces for PCs or Macs are typically designed for use in the _____ bus.
(a) ISA
(b) PCI
(c) SCSI
(d) PCMCIA
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.2.6 of the course notes.
--------------------------------------------------------------------------------
2.
In theory, the minimum RPC time on an Ethernet is 102 microseconds. In practice, getting the RPC time down to 1500 microseconds is a considerable achievement. What causes this difference?
(a) Ethernet has long delay time
(b) Large buffer on network interface card takes a while to fill up
(c) Operating system and protocol overhead
(d) Limited memory bandwidth between processor and network interface card
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.2.7 of the course notes.
--------------------------------------------------------------------------------
3.
A Web server is attending to five active requests from five different computers. How many sockets is this server using?
(a) 2
(b) 1
(c) 6
(d) 5
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
One socket is active to receive new requests, and five are active to transfer data. See section 2.2.1 of the course notes.
--------------------------------------------------------------------------------
4.
A Web server is attending to five active requests from five computers. It receives data sent via TCP to
(a) 6 TCP ports
(b) 2 TCP ports
(c) 1 TCP port
(d) 5 TCP ports
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.2.1 of the course notes.
--------------------------------------------------------------------------------
5.
Two machines are connected to each other with a 100 megabit/sec fiber connection. The round trip time between the machines is 80 milliseconds. What minimum size must the receive buffer be to allow the machines to utilize the full 100 megabits/sec?
(a) 1 megabyte
(b) 2 megabytes
(c) 500 kilobytes
(d) 8 megabytes
Correct answer is (a)
Your score on this question is: 20.00
Feedback:
See section 2.2.7 of the course notes.
--------------------------------------------------------------------------------
3.
A Web server is attending to five active requests from five different computers. How many sockets is this server using?
(a) 5
(b) 2
(c) 6
(d) 1
Correct answer is (c)
Your score on this question is: 0.00
Feedback:
One socket is active to receive new requests, and five are active to transfer data. See section 2.2.1 of the course notes.
3.
Which of the following will help to avoid context switches in network code?
Run one server for each client.
Library procedures that send data should buffer until a substantial amount is ready to be sent.
Data that arrives should be passed to the user as soon as possible after it arrives.
(a) I and III only
(b) III only
(c) II only
(d) I and II only
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.2.7 of the course notes.
1.
Which of the following are reasons IntServ (the Integrated Services Model) has not been widely deployed?
Concerns about complexity of the service model
Lack of demand for real-time services
Problems scaling to a large environment such as the Internet
(a) I only
(b) I, II, and III
(c) III only
(d) I and III only
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.3.3 of the course notes.
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2.
Which of the following statements about routers that use FIFO packet schedulers are true?
Each user has a separate queue in the router.
Users who send at higher rates despite congestion warnings will have the same throughput as users who send at lower rates.
(a) II only
(b) I and II
(c) None
(d) I only
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.3.2 of the course notes.
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3.
Six flows (A-F) share a 100-megabit-per-second line. Flow B is a dedicated 35-megabit-per-second line, and flow F is a dedicated 25-megabit-per-second line. The other four flows split the remaining bandwidth equally. What weights could be assigned to each flow in a WFQ scheduling router so that these requirements are met?
(a) A:4 B:2 C:4 D:5 E:4 F:1
(b) A:2 B:7 C:2 D:2 E:2 F:5
(c) A:1 B:3 C:1 D:1 E:1 F:2
(d) A:1 B:6 C:1 D:1 E:1 F:4
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.3.2 of the course notes.
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4.
If DiffServ (the Differentiated Services Model) supports the gold-silver-bronze service model, which of the following will that model guarantee?
Guaranteed minimum bandwidth
Guaranteed maximum delay
(a) II only
(b) I and II
(c) None
(d) I only
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.3.3 of the course notes.
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5.
A flow passes through a token bucket filter, then over a 10 megabit/sec Ethernet to a router. The token bucket size is 15K tokens. If the token bucket accumulates tokens at a rate of 1 million tokens per second and packets consume one token per byte, what is the maximum instantaneous throughput (i.e., the throughput during a very short time interval) of the flow to the router?
(a) 10 megabits/sec
(b) 1 megabit/sec
(c) 8 megabits/sec
(d) 125 kilobits/sec
Correct answer is (a)
Your score on this question is: 20.00
Feedback:
The token bucket will limit the average bandwidth used to 8 megabits/sec but will not prevent bursts of 10 megabits/sec.
1.
A flow passes through a token bucket filter, then over a 10 megabit/sec Ethernet to a router. The token bucket size is 15K tokens. If the token bucket accumulates tokens at a rate of 1 million tokens per second and packets consume one token per byte, what is the maximum instantaneous throughput (i.e., the throughput during a very short time interval) of the flow to the router?
(a) 10 megabits/sec
(b) 8 megabits/sec
(c) 1 megabit/sec
(d) 125 kilobits/sec
Correct answer is (a)
Your score on this question is: 20.00
Feedback:
The token bucket will limit the average bandwidth used to 8 megabits/sec but will not prevent bursts of 10 megabits/sec.
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2.
Six flows (A-F) share a 100-megabit-per-second line. Flow B is a dedicated 35-megabit-per-second line, and flow F is a dedicated 25-megabit-per-second line. The other four flows split the remaining bandwidth equally. What weights could be assigned to each flow in a WFQ scheduling router so that these requirements are met?
(a) A:1 B:6 C:1 D:1 E:1 F:4
(b) A:1 B:3 C:1 D:1 E:1 F:2
(c) A:2 B:7 C:2 D:2 E:2 F:5
(d) A:4 B:2 C:4 D:5 E:4 F:1
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.3.2 of the course notes.
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3.
Which of the following statements about routers that use FIFO packet schedulers are true?
Each user has a separate queue in the router.
Users who send at higher rates despite congestion warnings will have the same throughput as users who send at lower rates.
(a) I only
(b) I and II
(c) None
(d) II only
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.3.2 of the course notes.
--------------------------------------------------------------------------------
4.
If DiffServ (the Differentiated Services Model) supports the gold-silver-bronze service model, which of the following will that model guarantee?
Guaranteed minimum bandwidth
Guaranteed maximum delay
(a) I only
(b) I and II
(c) II only
(d) None
Correct answer is (d)
Your score on this question is: 20.00
Feedback:
See section 2.3.3 of the course notes.
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5.
The purpose of token buckets is
(a) to weigh the amount of traffic through a router
(b) to limit the amount of traffic entering a network
(c) to store copies of packets in case some are lost
(d) to combine packets into a smaller number of larger datagrams
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.3.2 of the course notes.
1.
If DiffServ (the Differentiated Services Model) supports the gold-silver-bronze service model, which of the following will that model guarantee?
Guaranteed minimum bandwidth
Guaranteed maximum delay
(a) II only
(b) I and II
(c) I only
(d) None
Correct answer is (d)
Your score on this question is: 20.00
Feedback:
See section 2.3.3 of the course notes.
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2.
In a WFQ scheduler, four flows A, B, C, and D are allocated weights 1, 1, 2, and 2, respectively. If all packets were the same size, in what order would the scheduler serve the queues?
(a) ABACADABACAD...
(b) ABCDABABCDAB...
(c) ABCABDABCABD...
(d) ACDBCDACDBCD...
Correct answer is (d)
Your score on this question is: 20.00
Feedback:
A and B should each get 1/6 the bandwidth; C and D should each get 1/3.
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3.
Which of the following does the original Internet service model guarantee?
A certain maximum packet delay
A certain minimum bandwidth
(a) II only
(b) I only
(c) I and II
(d) None
Correct answer is (d)
Your score on this question is: 20.00
Feedback:
See section 2.3.1 of the course notes.
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4.
Six flows (A-F) share a 100-megabit-per-second line. Flow B is a dedicated 35-megabit-per-second line, and flow F is a dedicated 25-megabit-per-second line. The other four flows split the remaining bandwidth equally. What weights could be assigned to each flow in a WFQ scheduling router so that these requirements are met?
(a) A:1 B:3 C:1 D:1 E:1 F:2
(b) A:2 B:7 C:2 D:2 E:2 F:5
(c) A:1 B:6 C:1 D:1 E:1 F:4
(d) A:4 B:2 C:4 D:5 E:4 F:1
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.3.2 of the course notes.
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5.
When an application submits a request for guaranteed service, which of the following will the signaling protocol contact?
Only the router with the lowest bandwidth along the path that the application will use
Only the first router along the path that the application will use
All routers along the path that the application will use
(a) I only
(b) I and II only
(c) II only
(d) III only
Correct answer is (d)
Your score on this question is: 20.00
Feedback:
See section 2.3.1 of the course notes.
1.
Six flows (A-F) share a 100-megabit-per-second line. Flow B is a dedicated 35-megabit-per-second line, and flow F is a dedicated 25-megabit-per-second line. The other four flows split the remaining bandwidth equally. What weights could be assigned to each flow in a WFQ scheduling router so that these requirements are met?
(a) A:4 B:2 C:4 D:5 E:4 F:1
(b) A:1 B:3 C:1 D:1 E:1 F:2
(c) A:2 B:7 C:2 D:2 E:2 F:5
(d) A:1 B:6 C:1 D:1 E:1 F:4
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.3.2 of the course notes.
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2.
If DiffServ (the Differentiated Services Model) supports the gold-silver-bronze service model, which of the following will that model guarantee?
Guaranteed minimum bandwidth
Guaranteed maximum delay
(a) I only
(b) I and II
(c) None
(d) II only
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.3.3 of the course notes.
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3.
The purpose of token buckets is
(a) to weigh the amount of traffic through a router
(b) to combine packets into a smaller number of larger datagrams
(c) to limit the amount of traffic entering a network
(d) to store copies of packets in case some are lost
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.3.2 of the course notes.
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4.
Which of the following are reasons IntServ (the Integrated Services Model) has not been widely deployed?
Concerns about complexity of the service model
Lack of demand for real-time services
Problems scaling to a large environment such as the Internet
(a) III only
(b) I only
(c) I, II, and III
(d) I and III only
Correct answer is (c)
Your score on this question is: 20.00
Feedback:
See section 2.3.3 of the course notes.
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5.
Which of the following does the original Internet service model guarantee?
A certain maximum packet delay
A certain minimum bandwidth
(a) I and II
(b) None
(c) II only
(d) I only
Correct answer is (b)
Your score on this question is: 20.00
Feedback:
See section 2.3.1 of the course notes.
1.
A flow passes through a token bucket filter, then over a 10 megabit/sec Ethernet to a router. The token bucket size is 15K tokens. If the token bucket accumulates tokens at a rate of 1 million tokens per second and packets consume one token per byte, what is the maximum instantaneous throughput (i.e., the throughput during a very short time interval) of the flow to the router?
(a) 1 megabit/sec
(b) 125 kilobits/sec
(c) 10 megabits/sec
(d) 8 megabits/sec
Correct answer is (c)