Matrix inversion in the design of active queue management mechanisms

A router exploiting the active queue management can drop arriving packets even if its buffer is not full. This is meant to notify the TCP senders to reduce their sending rates. One type of the active queue management is based on dropping arriving packets with probability that is a function of the queue size observed upon packet arrival. Although the queuing models of algorithms of this type have been developed, they present some numerical difficulties that have to be overcome in order to be practically usable, e.g. they require inverting large matrices. In this paper we compare several inversion methods with respect to their applicability in the parameterization of the dropping mechanism of the active queue management. In addition to their implementations on a CPU, we also check their performance when implemented on a graphics processor unit.