Delay of IP Packets

For ensuring a given Quality of Service in IP networks for the various packet streams arriving at a link, they are assigned to different queues. By prioritizing the queues or by an implementation of weighted Round Robin or weighted packet-wise Head of the Line Processor Sharing (weighted fair queueing: WFQ) a corresponding partition of the link capacity to the packet streams to be transported can be ensured.


Firstly, we analyze the delay of the IP packets of a single queue. The arrival process of the packets at the link is modeled by an Interrupted Poisson Process (IPP), where exponentially distributed on and off phases alternate. During the on phases there arrive packets of random length according to a Poisson process, during the off phases there is no packet arrival. The packets are served with constant speed (link rate) according to the FIFO discipline. From a mathematical point of view, the sojourn time in the queueing system IPP/GI/1 is analyzed.


Secondly, we analyze the delay of the IP packets of a marked queue under priority scheduling. For the marked queue priority scheduling means that its service is interrupted after a random duration U for a random duration D, where the service of a just served packet is finished. As an approximation of this mechanism, phase-type distributed random variables may be chosen for U and D. The arrival process is modeled by an IPP again, and the length of the packets is modeled by a phase-type distribution. From a mathematical point of view, the sojourn time in the queueing system IPP/PH/1 with a random environment is analyzed.


Thirdly, we deal with the problem of an efficient modelling of the superposition process of different IPP's and the splitting of an IPP in different IPP's, which is crucial in deriving algorithms for computing performance measures in IP networks.


Projektleitung
Brandt, Andreas Prof. Dr. (Details) (Quantitative Betriebswirtschaftslehre (J))

Laufzeit
Projektstart: 03/2007
Projektende: 12/2013

Zuletzt aktualisiert 2020-14-03 um 23:12