Comparisons of QoS from user´s perspective; which provides better utility to users, best effort or reservation-based services?

The conventional Internet has only provided the best-effort service, which does not offer any QoS (quality-of-service) guarantees. However, previous developments of multimedia applications require QoS guarantees for real-time transfers, which eventually introduced reservation-based protocols. However, it is pointed out that reservation-based protocols such as RSVP have several drawbacks such as a scalability problem. We introduce user´s utility to quantify QoS, and it is used to compare the best-effort and reservation-based services to discuss which service gives a better solution for real-time applications and data applications. By extending our previous results, we discuss the worst utility that the user experiences during the connection in this paper. The tandem network model is also treated to investigate the effect of multiple link systems on both services.