entify: Home routers: They are the routers residing in the customer's house as the delimitation point between the home network and the public network of the service provider; they generally are constituted by a layer 2 switch that inter- face the home Ethernet and on top of it a routing engine that interfaces the pub- lic Internet. Their maximum throughput comprises in general between 1 and 100 Mbit/s. Home routers are connected at layer 3 with BRAS. A BRAS is the first router of the public network that a packet traverses after leaving the customer appliance or a private network. Besides routing and forwarding IP packets, they also are responsible for access authentication and customer profiling; at the beginning of the introduction of broadband services, BRAS where also big computers with suitable programs, but this approach was rapidly found insufficient to follow the needed increase in BRAS throughput; thus, dedicated hardware-based BRAS was introduced, with an evolution path in term of internal architecture similar to that of core routers. BRAS are connected by core routers, that are the routers that execute routing and forwarding in geographically extended networks. They are complex and high throughput machines and the need of specialized hardware to reach the required performances was clear from the beginning of Internet. Nowadays, core routers are effectively divided into two categories: Giga-routers with a routing throughput on the order of hundreds of Gbit/s and Tera-routers with a routing throughput on the order of Tbit/s. These two routers categories lever- age generally different technologies, depending on the different required performances. Telecommunication Networks 7.8.2 IP Routers Architecture We have seen that the key operation carried out by a router is packet forwarding. Even if this operation could be done via software, only the low-capacity routers can use this tech- nique and generally a dedicated hardware is needed [68-70]. The first architecture of core routers, and an architecture that i