efficiently shapes the bandwidth usage on the characteris- tic of the most bandwidth-consuming services. The downstream bit rate needed for different triple play configurations is reported in Table 2.2. From the table, it is quite evident that the most bandwidth-demanding configu- ration is also accommodated with an access bandwidth of 50 Mbit/s, thereby fixing the order of magnitude of the target bandwidth for the next generation access network. In line with this evaluation, many carriers target a future access delivering 00Mbit/s to every user to maintain scalability in front of the introduction of new services. Up to now, we have considered real services, that is, products that carriers offer to the retail customer. It is not possible to close the discussion about services for the retail market without also considering pair-to-pair applications. In a pair-to-pair application, the content of the service is not delivered by the carrier or by another service provider via the carrier network, but it is generated by a customer. For example, in a typical peer-to-peer service, a community of customers store in a net- work repository the digital version of the films they have bought on DVD. Every customer, under the only condition of a forum subscription, can access the repository and download the content he needs. It is not possible here to enter into the details of the complex legal issues implied by this content management. As a matter of fact, films, music, books, and SO on are protected by Drivers for Telecommunication Network Evolution TABLE 2.2 Downstream Bit Rates for All-Digital Triple-Play Mbit/s Mbit/s Video Services with MPEG-2 Compression Internet (average user) Internet (high user) Telephony Telephony 2 SDTV channels 2 SDTV channels 1 HDTV channel 2 HDTV channels Total Total Video Services with MPEG-4 Compression Internet (average user) Internet (high user) Telephony Telephony 2 SDTV channels 2 SDTV channels 1 HDTV channel 2 HDTV channel Total Total copyright and the boundary of a legal exchange of conte