Buffer Management of Multi-Queue QoS Switches with Class Segregation

In this paper, we focus on buffer management of multi-queue QoS switches in which packets of different values are segregated in different queues. Our model consists of $m$ queues and $m$ packet values $0 < v_{1} < v_{2} < ... < v_{m}$. Recently, Al-Bawani and Souza [IPL 113(4), pp.145-150, 2013] presented an online algorithm GREEDY for buffer management of multi-queue QoS switches with class segregation and showed thatif $m$ queues have the same size, then the competitive ratio of GREEDY is $1+r$, where $r=\max_{1 \leq i \leq m-1} v_{i}/v_{i+1}$. In this paper, we precisely analyze the behavior of GREEDY and show that it is $(1+r)$-competitive for the case that $m$ queues do not necessarily have the same size.