Exam 7: Data Link Control Protocols

RR and RNR are examples of an ________.

The most important data link control protocol is ________.

If two stations exchange data each needs to maintain two windows,one for transmit and one for receive,and each side needs to send the data and acknowledgments to the other.To provide efficient support for this requirement a feature known as ________ is typically provided.

With ________ ARQ the only frames retransmitted are those that receive a negative acknowledgment or those that time out.

The flag field pattern is ________.

_______ provide the ARQ mechanism in HDLC when piggybacking is not used.

Selective reject is a useful choice for a satellite link because of the long propagation delay involved.

Data are sent in blocks called ________.

Since there is no assurance that the flag field pattern will not appear somewhere inside the frame,a procedure known as ________ is used to prevent destroying synchronization.

The effect of ARQ is to turn an unreliable data link into a reliable one.

Transmission time is not proportional to the length of the frame.

In situations where the bit length of the link is greater than the frame length,serious inefficiencies result.

A technique for assuring that a transmitting entity does not overwhelm a receiving entity with data is ________.

A layer of logic is added above the physical layer to achieve necessary control.This logic is referred to as a ________ protocol.

The time it takes for a station to emit all of the bits of a frame onto the medium is the ________ time.

________ enables a receiver to regulate the flow of data from a sender so that the receiver's buffers do not overflow.

In the HDLC frame structure the FCS and flag fields following the data field are referred to as a ________.

The form of flow control where a source entity transmits a frame and must wait until it receives an acknowledgment back from the destination entity before sending the next frame is ________ flow control.

The form of error control based on sliding-window flow control that is most commonly used is:

HDLC uses asynchronous transmission.