(1) is a one -way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string.
(2) is a protocol that most USENET machines now use it to allow news articles to propagate from one machine to another over a reliable connection.
(3) is an approach preferred by cable TV providers. In this solution the fiber terminates at an optoelectrical converter and the final segment is a shared coaxial cable.
(4) is a device used to connect two separate network that use different communication protocol.
(5) is a digital-to-digital polar encoding method in which the signal level is always either positive or negative.
A.MD
B.RSA
C.DES
D.MIB
A.PSTN传令协议
B.BCC协议
C.保护协议
D.以上全部
A.正向应答
B.负向应答
C.正向应答或负应回答
D.双向应答
A.系统文件
B.连续文件
C.记录文件
D.库文件
A.成本决策
B.成本控制
C.成本分析
D.系统运行管理