Recently there has been much interest in combining the speed of layer-2 switching with the features of layer-3 routing. This has been prompted by numerous proposals, including: IP Switching [1], Tag Switching [2], ARIS [3], CSR [4], and IP over ATM [5]. In this paper, we study IP Switching and evaluate the performance claims made by Newman et al in [1] and [6]. In particular, using ten network traces, we study how well IP Switching performs with traffic found in campus, corporate, and Internet Service Provider (ISP) environments. Our main finding is that IP Switching will lead to a high proportion of datagrams that are switched; over 75% in all of the environments we studied. We also investigate the effects that different flow classifiers and various timer values have on performance, and note that some choices can result in a large VC space requirement. Finally, we present recommendations for the flow classifier and timer values, as a function of the VC space of the switch and the network environment being served.
['Steven Lin', 'Nick McKeown']
A simulation study of IP switching