 as if the transparent transport network was destined to last a few years: the time needed to develop the real next generation network. It is not surprising that the first research attempt on the transparent optical packet net- work (T-OPN) was defeated by the lack of even the most basic components needed for packet processing. As a matter of fact, packet processing is intrinsically a digital operation, while optical equipment is essentially analog. An optical packet switch can be, in general, represented as in Figure 10.35, and a simpli- fied process corresponding to the arrival of a packet, and its forwarding to the following node of its path through the network can be described as follows: The interface with the line detects at the correct layer the arrival of a packet. If the input queue is full, the packet is discarded and the event is registered. If there is free memory in the input queue, the packet is stored in the line card. The line card processor reads the packet header and verifies if it is correct. If the packet header is correct, the destination address is extracted and sent to the routing processor. The routing processor accesses the routing and forwarding tables and determines the destination output port. The switch is configured to allow the packet to reach the correct output port. The packet is transmitted to the output port via the switch and stored in the out- put queue. The packet is conditioned for transmission in the line and leaves the router. It is clear that no optical equipment can carry out a set of such complex operations that are tailored for digital processors more than for optical systems. On the other hand, the target of the research on the optical packet switching is not the execution of all the operations that happens in a router at the optical level, but to never have the need of transforming the packet payload from optical to electrical during the router passing through process. Telecommunication Networks In this way, on one side, it would be possible to transmit a very high b