This is called receiver congestion. Second, a network node needs to send more frames across a given line than the speed of the line permits, which is called line congestion. As a result, it is very important that the frame relay network have excellent congestion management features both to minimize the occurrence and severity of congestion and to minimize the effect of the discards when they are required. Congestion management features are discussed in more detail in the following chapter. If the network has a problem handling a frame due to line errors or congestion, it simply discards the frame.
Frame relay requires lines with low error rates to achieve good performance.