The RDSI (ISDN) is an evolved technology of the network of telephone of wiring of pair of copper RDI (Red Digital Integrada), this one gives digital connections from a side to another one providing a great fan of services by means of interfaces standardized for the clients. This Integra system digital data and of voice in the same structure. Isdn (RDSI) has a type of called connection BISDN that works under the broadband line, being able of to fuse both services thanks to the technology of the optical fiber being opteniendo higher speeds. This technology owns much quality and high speeds that work under the flexibility of the service of the wire net. This system among others has several uses in the world of the communication being the most important connection to Internet. The ample necessity to transfer contents multimedia and data requires of faster connections of Internet, being this system able to work with volumes of great size and giving less errors in the unloadings of contents.

The speed is of 64 Kbps (channel B) and 16 Kbps (channel D) having the user in the combination of 128 channels Kbps being quicker than a 28.8 modem of Kbps. Technology RDSI assures a connection to Internet more quality. The basic interface on watch (BRI) is the destined one for the home and the small company and the interface of primary speed (PRI) for great users. Each tariff owns a number of specific channels for the transmission of services. Line ADSL for houses and companies are of a 256 bandwidth of Kbps and 2 Mbps being the difference with respect to technology RDSI of the 128 Kbps of its two channels, this last one is more expensive. Perhaps channels RDSI do not get to fulfill all the exigencies of the users yes although that owns functions enough optimal ones for certain user group. The speed of connection and its tariffs make of the ADSL a perfect election since their tariffs are chords to the line contracted by the client. In order to study supplies ADSL and more attractive connections for the consumer, exist a comparative Web ADSL with all the information necessary and useful to be able to sail by the network with the package that is resembled our needs more.