Networks are handled as: Congestion is defined as the situation when exchanges or circuit groups are inundated with calls and are unable to serve all the subscribers.
Overflow systems make use of alternative routing circuit groups or paths to transfer excess traffic and thereby reduce the possibility of congestion.
As a supporting network, it carries all the signalling messages necessary to set up, break down or provide extra services.
Call centers use teletraffic theory to increase the efficiency of their services and overall profitability through calculating how many operators are really needed at each time of the day.
If callers are made to wait too long, they may lose patience and default from the queue (hang up), resulting in no service being provided.
Teletraffic engineering is a well-understood discipline in the traditional voice network, where traffic patterns are established, growth rates can be predicted, and vast amounts of detailed historical data are available for analysis.
An important reason for this is that computing power has become far more accessible, making simulation the preferred analytical method for problems that are not easily solved mathematically.