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25 Cards in this Set
- Front
- Back
Communication at the data-link layer is |
node-to-node |
|
Communication at the network layer is |
host-to-host |
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An ARP request is normally |
broadcast |
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An ARP reply is normally |
unicast |
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Packet at the data-link layer is normally called a |
frame |
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Data-link layer of a broadcast link has ___________sublayer(s). |
two |
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Data-link layer of a point-to-point link has __________ sublayer(s). |
one |
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3. How many IP addresses and how many link-layer addresses should a router have when it is connected to five links? |
5 IP addresses and 5 link-layer addresses. |
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Do we need to always keep the ARP program running on a host or a router? Why? |
Yes, because ARP need to listen the ARP broadcast. |
|
Hub |
is a repeater, bits coming in one link go out all other links |
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Switch |
is link-layer device, and smarter than hubs, take active role, store,forward Ethernet frames |
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Router |
is a network layer device, and smarter than switch, translate between different protocols. |
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Which error detection method involves polynomials? |
CRC |
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In CRC, the quotient at the sender_______. |
is discarded. |
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At the CRC checker, _______ means that the dataword is damaged. |
a nonzero remainder |
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To detect five-bit errors, the Hamming distance between each pair ofcodewords should be at least_________. |
6 |
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To correct five-bit errors, theHamming distance between each pair of codewords should be at least_________. |
11 |
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A checksum can _________ errors. |
both detect and correct |
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If 3 bits are used for the framesequence number in Go-Back-N ARQ, the size of the sender’s window Ssize canhave the following value (hint: 2^3 = 8) |
5 frames |
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Considera Stop-and-Wait ARQ protocol that uses a time-out period of 18 ms(milliseconds). The round trip time between the sender and receiver is 10 ms. The transmission time of a frame is 2 ms. The value of the utilizationof this protocol in an error-free channel is |
2/12 |
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The timeout counter in the Go-Back-N ARQ protocol is used to |
initiate frame retransmission |
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In Go-Back-N, the values of Sf = 3 and Sn = 7,after receiving a packet with ackNo = 6, the value of Sf is_______________. |
6 |
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Two methods used in separating one frame from the next |
byte stuffing and bit stuffing |
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Two ARQ protocols in which the receiver has a buffer of size one frameare |
Stop-and-Wait and Go-Back-N |
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Two ARQ protocols that use sliding window are |
Go-Back-N and Selective Repeat |