Chapter 5 The Link Layer and Local Area Network
1．A (  ) protocol is used to move a datagram over an individual link.
A    application-layer       
B    transport-layer
C    network-layer           
D    link-layer
2．The units of data exchanged by a link-layer protocol are called (  ).
A    datagrams               
Bserver error啥意思    frames
C    segments               
D    messages
3．Which of the following protocols is not a link-layer protocol? (  )
A    Ethernet               
B    PPP
C    HDLC                   
D    IP
4．In the following four descriptions, which one is not correct? (  )
A    link-layer protocol has the node-to-node job of moving network-layer datagrams over a single link in the path.
B    The services provided by the link-layer protocols may be different.
C    A datagram must be handled by the same link-layer protocols on the different links in the path.
D    The actions taken by a link-layer protocol when sending and receiving frames include error detection, flow control and random access.
5．Which of the following services can not offered by a link-layer protocol? (  )
A    congestion control               
B    Link Access   
C    Error control                   
D    Framing
6．(  ) protocol serves to coordinate the frame transmissions of the many nodes when multiple nodes share a single broadcast link.
A    ARP       
B    MAC   
C    ICMP   
D    DNS
7．In the following four descriptions about the adapter, which one is not correct? (  )
A    The adapter is also called as NIC.
B    The adapter is a semi-autonomous unit.
C    The main components of an adapter are bus interface and the link interface.
D    The adapter can provide all the link-layer services.
8．Consider CRC error checking approach, the four bit generator G is 1011, and suppose that the data D is 10101010, then the value of R is(  ).
A      010     
B      100     
C      011       
D      110
9．In the following four descriptions about random access protocol, which one is not correct? (  )
A      In slotted ALOHA, nodes can transmit at random time.
B      In pure ALOHA, if a frame experiences a collision, the node will immediately retransmit it with probability p.
C      The maximum efficiency of a slotted ALOHA is higher than a pure ALOHA.
D      In CSMA/CD, one node listens to the channel before transmitting.
10．In the following descriptions about MAC address, which one is not correct? (  )
A      The MAC address is the address of one node’s adapter.
B      No two adapters have the same MAC address.
C      The MAC address doesn’t change no matter where the adapter goes.
D      MAC address has a hierarchical structure.
11．The ARP protocol can translate (  ) into (    ). (  )
A      host name, IP address         
B      host name, MAC address
C     IP address, MAC address       
D    broadcast address, IP address
12．The value of Preamble field in Ethernet frame structure is (  )
A    10101010 10101010……10101010 11111111
B    10101011 10101011……10101011 10101011
C    10101010 10101010……10101010 10101011
D    10101010 10101010……10101010 10101010
13．There are four steps in DHCP, the DHCP server can complete (  ).
A    DHCP server discovery           
B    DHCP server offers
C    DHCP request                   
D    DHCP response
14．In CSMA/CD, the adapter waits some time and then returns to sensing the channel. In the following four times, which one is impossible? (  )
A    0 bit times           
B    512 bit times
C    1024 bit times       
D    1028 bit times
15．The most common Ethernet technologies are 10BaseT and 100BaseT. “10” and “100” indicate(  ).
A    the maximum length between two adapters
B    the minimum length between two adapters
C    the transmission rate of the channel
D    the transmission rate of the node
16．The principal components of PPP include but not(  ).
A    framing                   
B    physical-control protocol 
C    link-layer protocol         
D    network-layer protocol
17．In the following four options, which service can not be provided by switch? (  )
A    filtering                   
B    self-learning
C    forwarding                 
D    optimal routing
18．In the following four services, which one was be required in PPP? (  )
A    packet framing             
B    error detection
C    error correction            
D  multiple types of link
19．The ability to determine the interfaces to which a frame should be directed, and then directing the frame to those interfaces is(  ).
A  filtering                   
B  forwarding
C  self-learning               
D  optimal routing
20．In (  ) transmission(s), the nodes at both ends of a link may transmit packets at the same time.
A    full-duplex               

版权声明：本站内容均来自互联网，仅供演示用，请勿用于商业和其他非法用途。如果侵犯了您的权益请与我们联系QQ:729038198，我们将在24小时内删除。