5．Which of the following rvices can not offered by a link-layer protocol? ( )
A congestion control
B Link Access
C Error control
scheduleD Framing
6．( ) protocol rves 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 mi-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 rvices.
8．Consider CRC error checking approach, the four bit generator G is 1011, and suppo that the data D is 10101010, then the value of R is( ).
A 010
B 100 chargeback
C 011
D 110
9．In the following four descriptions about random access protocol, which one is not correct? ( )
A adverbialIn 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 rver can complete ( ).
A DHCP rver discovery
B DHCP rver offers
C DHCP request
D DHCP respon
14．In CSMA/CD, the adapter waits some time and then returns to nsing 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 10BaT and 100BaT. “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 rvice can not be provided by switch? ( )
A filtering
B lf-learning
C forwarding
D optimal routing
18．In the following four rvices, 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 tho interfaces is( ).
A filtering
B forwarding
C lf-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 上海海关学院分数线
