C. A function that makes remote procedures appear to be local
D. The point where upper-layer processes access transport layer services
16) Which of the following services uses a process called windowing (下面的哪一个服务使用了所谓的窗口机制)?
A. Reliable data transfer
B. Connection-oriented virtual circuit
C. Buffered transfer
D. Resequencing
E. Multiplexing
F. Efficient, full-duplex transmission
G. Flow control
17) What is UDP (什么是U D P )?
A. An API that makes the transport layer independent
B. A connectionless, unreliable transport protocol