How does TCP sender perceive congestion?( )
A. Through a timeout event
B. Through a receiving duplicate ACK-s event
C. Both A and B
D. Either A or B
查看答案
Extending host-to-host delivery to process-to-process delivery is called transport-layer ____ and .
A. multiplexing and de-multiplexing
B. storing and forwarding
C. forwarding and filtering
D. switching and routing
UDP is a ____ service while TCP is a connection-oriented service.
A. Connectionless
B. Reliable
Connection-oriented
D. In-order
The UDP header has only four fields, they are____.
A. Source port number, destination port number, length and checksum
B. Source port number, destination port number, source IP and destination IP
C. source IP, destination IP, source MAC address and destination MAC address
D. source IP, destination IP, sequence number and ACK sequence number
There are two 16-bit integers: 1110 0110 0110 0110, 1101 0101 0101 0101. Their checksum is____.
A. 0100010001000011
B. 1011101110111100
C. 1111111111111111
D. 1000000000000000
微信支付 
支付宝支付