l direction. Repeating the traffic evaluation in this case, we will find that each ONU that is served by a GbE channel has to manage a traffic constituted by 500Mbit/s of broadcast IpTV, and a total of 73.5 Mbit/s of point-to-point traffic constituted by 18kbit/s of Ip phone (this is naturally an average value since it is lower that the base Ip phone rate), 17.5Mbit/s of web browsing, and 56Mbit/s due to individual video programs. The total amount of traffic is about 574 Mbit/s. We have to take into account that the efficiency of the GbE channel should not be pushed to the limit as it might risk congesting the far end switch. Let us image reaching a 68% efficiency of the GbE, which is a net capacity of about 0.81 Gbit/s. The free capacity per ONU is in this case 236 Mbit/s and globally 3.7 Gbit/s. If we want to evaluate how many VoD channels we can allocate, it would be mis- leading to divide Gbit/s per 16Mbit/s, since in this case it is not possible to distribute in a dynamical way, the bandwidth among different groups of users as is possible in the case of a GPON. The only result that can be considered is that with the WDM-PON, it is possible to open 14 VoD channels for each of the 16 ONUs. The result is that the comparison between the two architectures is quite difficult. If the service penetration is uniform, and corresponds to an area covered by the uniform central office from a social point of view, the WDM-PON is much more effective in delivering point-to-point services that have high activity. If the penetration of the service is very inhomogeneous, the WDM-PON advantage gets smaller and smaller. Capacity: XG-PON1 versus XWDM-PON Under a qualitative point of view, the situation is exactly the same as we described in the previous section. The relevant difference is that if such very high capacity systems have been adopted, this means that the penetration of high capacity and high peak bandwidth services are already here. In this case, the much higher total capacity of the XWDM-PON gets, for sure, a better 