In this paper two different paradigms to realize a scalable all-optical packet switch with label swapping will be reviewed. All the functions required for switching the packets are based on all-optical signal processing without any electronic control. This allows very low latency and potential photonic integration of the systems. We report for both techniques experimental results showing the routing operation of the 160 Gb/s packets and beyond. We will discuss and compare both techniques in term of devices and bit-rate scalability, latency, power consumption, power penalty performance and cascadability as key parameters for the realization, of an all-optical packet switch.