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Bridges introduce some latency, which is called a “hop delay”, but normally operate as fast as the devices they interconnect. Bridges tend to lose packets if a destination network is heavily loaded and data cannot be forwarded as fast as it is received from the originating network. Bridges can be programmed to forward messages selectively; this is often exploited to avoid a problem whereby the load on a network can grow without limit as the size of the network is increased – the load on a bridged network is the sum of the load local to a segment, and the load forwarded over the bridge, and can be much less than the sum of the loads on all segments.

However, other processes that may be interacting with the faulty process also have a completely accurate way to detect such failures. For example, a fail-stop environment might be one in which timeouts can be used to monitor the status of processes, and no timeout occurs unless the process being monitored has actually crashed. Obviously, such a model may be unrealistically optimistic, representing an idealized world in which the handling of failures is reduced to a pure problem of how the system should react when a failure is sensed.

Timing failures: These occur when a temporal property of the system is violated, for example when a clock on a computer exhibits a value that is unacceptably far from the values of other clocks, or when an action is taken too soon or too late, or when a message is delayed by longer than the maximum tolerable delay for a network connection. • Byzantine failures: This is a term that captures a wide variety of “other” faulty behaviors, including data corruption, programs that fail to follow the correct protocol, and even malicious or adversarial behaviors by programs that actively seek to force a system to violate its reliability properties.