r, 50% of the subscribers who have IpTv will use it. It is to take into account that the IpTv is a multicast channel, thus the overall traffic for IpTv is, on an average, 0.5 Erlang per customer. Carrying out classical traffic computations, the average traffic partition in the peak hour is obtained as shown in Figure 11.4. This figure also shows the efficiency and the weakness of current GPON downstream bandwidth management. As a matter of fact, if low activity services should be added, there is plenty of bandwidth to support a good diffusion. The effective browsing time can be halved as far as the trans- mission speed is concerned, for all the users, consuming only a small part of the available bandwidth, and even a doubling of the number of IpTV customers will present no problems. The problem comes when services with high activity, as VoD or pair-to-pair video streaming, are considered. For example, the residual capacity allows 70 contemporary VoD channels to be distrib- uted, and if there is an important penetration of VoD, with more than one VoD-enabled TV in high spending families, this figure would not be enough. However, this scenario does not seem to be realistic in the near future, thus, with the service bundles that can be envisaged, the GPON seems to have quite a sufficient down- stream capacity. Let us now consider the upstream capacity. Even eliminating broadcast, presently, sev- eral services require less upstream bandwidth with respect to downstream, but in the near future, this trend could change due to the growing importance of point-to-point services. In the case of the upstream, the user activity is even smaller that the average activity of the downstream, the ONU performs statistical multiplexing on the line and the OLT queu- ing guarantees the absence of lost packets. Moreover, in the downstream direction, the DBA allows peak requests from specific ONUs to be allocated using the capacity flexible assignment. Thus, on top of a bare average physical bandwidth per user equal to about 39 Mbit/s, 