Knowledge checks


Components of packet delay.



Match the description of each component of packet delay to its name in the pull down list.



Question List:
Answer List:
  1. Queueing delay

  2. Transmission delay

  3. Propagation delay

  4. Processing delay


 

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1/10

Computing Packet Transmission Delay(1).



Suppose a packet is L = 1500 bytes long (one byte = 8 bits), and link transmits at R = 1 Gbps (i.e., a link can transmit bits 1,000,000,000 bits per second).  What is the transmission delay for this packet? [Note: you can find more problems like this one here.]




 

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2/10

Computing Packet Transmission Delay (2).



Suppose a packet is L = 1200 bytes long (one byte = 8 bits), and link transmits at R = 100 Mbps (i.e., a link can transmit bits 100,000,000 bits per second).  What is the transmission delay for this packet? [Note: you can find more problems like this one here.]




 

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3/10

Computing Packet Transmission Delay (3).



Consider the network shown in the figure below, with three links, each with the specified transmission rate and link length. Assume the length of a packet is 8000 bits.

What is the transmission delay at link 2?  [Note: you can find more problems like this one here.]




 

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4/10

Computing Propagation Delay.



Consider the network shown in the figure below, with three links, each with the specified transmission rate and link length. Assume the length of a packet is 8000 bits. The speed of light propagation delay on each link is 3x10^8 m/sec

What is the propagation delay at (along) link 2?




 

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5/10

Computing throughput: a simple scenario.



What is the maximum throughput achievable between sender and receiver in the scenario shown below?






 

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6/10

Computing throughput. 



Consider the scenario shown below, with four different servers connected to four different clients over four three-hop paths. The four pairs share a common middle hop with a transmission capacity of R = 300 Mbps. The four links from the servers to the shared link have a transmission capacity of RS = 50 Mbps. Each of the four links from the shared middle link to a client has a transmission capacity of RC = 90 Mbps.

What is the maximum achievable end-end throughput (an integer value, in Mbps) for each of four client-to-server pairs, assuming that the middle link is fairly shared (divides its transmission rate equally) and all servers are trying to send at their maximum rate?

Your answer: [A] Mbps

[Note: more questions like this one can be found here.]




 

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7/10

Computing utlilization (1).



Consider the scenario shown below, with four different servers connected to four different clients over four three-hop paths. The four pairs share a common middle hop with a transmission capacity of R = 300 Mbps. The four links from the servers to the shared link have a transmission capacity of RS = 50 Mbps. Each of the four links from the shared middle link to a client has a transmission capacity of RC = 90 Mbps.

Assuming that the servers are all sending at their maximum rate possible, what are the link utilizations for the server links (with transmission capacity RS)? Enter your answer in a decimal form of 1.00 (if the utilization is 1) or 0.xx (if the utilization is less than 1, rounded to the closest xx).

Your answer: The utilization of the server links is: [A]

[Note: more questions like this one can be found here.]




 

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8/10

Computing utilization (2).



Consider the scenario shown below, with four different servers connected to four different clients over four three-hop paths. The four pairs share a common middle hop with a transmission capacity of R = 300 Mbps. The four links from the servers to the shared link have a transmission capacity of RS = 50 Mbps. Each of the four links from the shared middle link to a client has a transmission capacity of RC = 90 Mbps.

Assuming that the servers are all sending at their maximum rate possible, what are the link utilizations of the shared link (with transmission capacity R)? Enter your answer in a decimal form of 1.00 (if the utilization is 1) or 0.xx (if the utilization is less than 1, rounded to the closest xx).

Your answer: The utilization of shared link is: [A]

[Note: more questions like this one can be found here.]




 

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9/10

Computing utilization (3).



Consider the scenario shown below, with four different servers connected to four different clients over four three-hop paths. The four pairs share a common middle hop with a transmission capacity of R = 300 Mbps. The four links from the servers to the shared link have a transmission capacity of RS = 50 Mbps. Each of the four links from the shared middle link to a client has a transmission capacity of RC = 90 Mbps.


Assuming that the servers are all sending at their maximum rate possible, what are the link utilizations of the client links (with transmission capacity RC)? Enter your answer in a decimal form of 1.00 (if the utilization is 1) or 0.xx (if the utilization is less than 1, rounded to the closest xx).

Your answer: The utilization of client link is: [A]

[Note: more questions like this one can be found here.]




 

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10/10

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