We have examined different quality of service, multiplexing, and virtual circuit management policies, and evaluated their relative merits from the standpoint of the performance of typical Internet applications. Our evaluation uses a simulation of a large IP internetwork and network traffic as sent by common Internet applications. The results show that the use of different scheduling algorithms and QOS parameters can be used to express preference for (or to restrict) certain applications. We see that multiplexing can improve application performance due to a reduced need to set up ATM virtual circuits, although interactions with some network service disciplines can negate these effects. Finally, we show that caching idle virtual circuits for reuse is, in general, beneficial for both network and application performance.