The main function of transmitter in data communications system is（）
A. transmitting signal from source to destination
B. transmitting data from source to media
C. generating data to be transmitted
D. generating signal which is suitable to be transmitted in the communication system
查看答案
IP protocol is located in the（）of TCP/IP architecture
A. application layer
B. transmission layer
C. internet layer
D. network access layer
Among the following options, that not described in the network architecture is（）
A. the implementation details in protocol
B. networks layers
C. protocols used in each layer
D. the function of each layer
ARPANET is the predecessor of Internet，and it is a（）
A. circuit switching network
B. message switching network
C. packet switching network
D. hybrid switching network
In OSI/RM architecture,the lowest is（）
A. application layer
B. network layer
C. transmission layer
D. physical layer
微信支付 
支付宝支付