providing quality of service for applications such as voice over ip and enforcing service level agreements are major requirement in any current and future communication networks . on the other hand , more communication networks are employing adaptive transmission mechanisms , such as dvb - s2 acm in satellite communication networks . in non - adaptive networks , qos enforcers use static bit rate configurations . however , using a static bit rate configuration in an adaptive network may result in underflow situations , during which it may not be possible to utilize the full capacity of the transmission channel and expensive resources may therefore be wasted , in addition , using a static bit rate configuration in an adaptive network may result in overflow situations , during which it may be necessary to drop user traffic packets and therefore quality of service may not be maintained . it is therefore imperative that qos enforcers have knowledge of the network &# 39 ; s available bit rate at all times . this invention describes a method for achieving exactly that .