OverflowIn general usage, an overflow occurs when the volume of a substance exceeds the capacity of its intended container. A river in flood, for instance, may "overflow its banks". It is also used in a metaphorical sense, as "overflowing with enthusiasm."
In telecommunication, the term overflow has the following meanings:
3. In telephony, traffic handled by overflow equipment.
4. In telephony, traffic that exceeds the capacity of the switching equipment and is therefore lost.
5. In telephony, on a particular route, excess traffic that is offered to another route, i.e. , an alternate route.