The results presented in this chapter rely on the fact that the bandwidth ratio between core and access links, N, is greater than 500 for the core of the network today. In the future, this ratio will continue to remain high, as the network topology design will probably not change: with lower-speed tributaries feeding into higher-speed links as we move further into the core. The reason behind this topology design is that the network performance is more predictable. If the ratio N were small, even with packet switching, end users would perceive a big difference between an unloaded network and a moderately loaded one with only a few other users.
In addition, as we have just seen, in the future access links will become faster and so the difference between the response time of circuit switching and packet switching will become negligible. So, it is safe to assume that the response time of circuit and packet switching in the core of the network will remain the same in the future.