“…• call queuing [12]- [16], which allows calls to wait until access to the system is possible in the case of a temporary lack of resources; • dynamic resource reservation [17]- [20], in which certain load levels (thresholds) are introduced into the system that, when exceeded, allow the system to service calls of strictly defined call classes only; • priorities [21], [22], which allow the operator to determine the significance of individual call classes and to assign preferences in allocated resources; • traffic compression [9], [11], [13], [23]- [25], which makes it possible to change the bitrates of serviced calls depending on the load of the system; • traffic overflow [26]- [28], which is based on redirecting the call that cannot be serviced in one system to another system that has a sufficient number of resources to service this call.…”