Event classes need to be modified to send IP datagrams instead of ATM cells between components. The traffic models attached to the end-nodes need to be substantially modified as they must generate IP packets rather than ATM cells. It is unfortunate that the existing traffic models generate ATM cells, had they been designed to generate AAL PDUs, with the network model generating ATM cells from the AAL PDUs in the end-nodes, then the modifications required would be smaller. Finally, the location where statistics are collected must be altered.
Statistical information needs to be collected at the layer at which routing or switching occurs.
ATM performs switching in the link layer, while IP routing occurs in the network layer.