cting packets and leaving upper layers to recover packet loss. We will have 180 input channels after demultiplexing; thus, we need 180 input queues. If the queues are realized as described in this section, assuming that no QoS has to be implemented, we have 720 SOAs in the memory loops and 2160 switch 2 X 2 that, due to the required speed, we can imagine building also with SOAs, increasing the number of SOAs in the front stage of the switch to 9360. The switch driving signal has to be prepared by the header processor that has to poten- tially manage 180 packet per slot. Moreover, a Banyan network has N log(N) crosspoints if N is the number of ports; thus, we need 935 SOAs for the switches and 360 for the ports. Moreover, at each output port, a WC has to be present to adapt the channel wavelengths to the wavelengths available on the output DWDM system. If SOA MZIs are used, this means that another 360 SOAs are needed. Globally, we need about 11,000 SOA. With present day technology, it is impossible to build an equipment integrating 11,000 SOAs, but if InP technology evolves strong and fast, something similar could happen. Moreover, we have to consider that the signal in a typical passage through the switch will traverse at least 20 SOAs. They are in quite different configurations with different Telecommunication Networks gains. Tracing a generic state of the switch, and assuming that the system is designed to have an overall gain equal to 0dB, the overall noise figure of the switch results to be around 40 dB, that is generally too much to allow the use in a transparent network. This underlines how a scheme like the one we have analyzed is far from the possibility of being transformed into a product. Nevertheless, it demonstrates that all-optical packet switching is in principle possible, even if important technological steps are still to be realized. 10.4.2 Final Comment on the All-Optical Packet Network In this section, we have presented just an example of possible implementation of optical packet switching netwo