In the frame relay LAPF frame, a 1-bit field indicating the eligibility of the frame for discard under conditions of network congestion. Theoretically, the user equipment sets the DE in consideration of the acceptability of the application to packet loss. Should the user equipment not set the DE, the network routers and switches may do so on a random basis or to police traffic that exceeds the CIR. SDLC, voice, and video traffic, for example, do not tolerate loss gracefully, and so typically are engineered to avoid DE status. File transfer and e-mail applications are not time-sensitive and, therefore, are highly insensitive to latency and loss.Therefore, the user may offer them to the network marked DE and pay a lower cost. See also congestion, frame relay, LAPF, latency, and SDLC.