Modelling Time-dependent Flows of Virtual Connections in ATM Networks

• Autorzy: Czachórski T. , Pekergin F.
• Języki publikacji: EN

Abstrakty

EN

The paper discusses the use of diffusion and fluid flow approximations in modelling the time-varying flows of cells which belong to different connections but are routed through the same ATM network switch. When the cells are leaving the switch, their class should be known to define the next routing. In steady-state queueing models the probability that customer belongs to a class k is obtained as the ratio of the class k through put to the whole throughput passing the node. We are interested in transient analysis where the throughputs are changing and the composition of multiclass flow at the entrance of a queue is not the same as at the output: we should consider the delay introduced by the queue the distribution of which is also changing with time. Numerical examples, validated by simulation, testify that diffusion approximation approach gives satisfactionary results in the solution of this problem. The fluid flow approximation is much simpler to implement and needs relatively less computation effort but gives worse results: the reason of it is that in the modelling the delay introduced by a switch queue, the distribution of the queue is important and the reasoning based only on its mean value is oversimplified.

Słowa kluczowe

EN

performance evaluation; ATM networks; diffusion approximation; fluid flow approximation

• Wydawca: Polska Akademia Nauk, Wydział IV Nauk Technicznych
• Czasopismo: Bulletin of the Polish Academy of Sciences. Technical Sciences
• Rocznik: 2000
• Tom: Vol. 48, nr 4
• Strony: 619--628
• Opis fizyczny: 5 rys., bibliogr. 18 poz.

Twórcy

autor

Czachórski T.

autor

Pekergin F.

• Institute of Theoretical and Applied Computer Science, Polish Academy of Sciences, 44-100 Gliwice, ul. Bałtycka 5, Poland (Instytut Informatyki Teoretycznej i Stosowanej PAN)