2 Digital subscriber line VDSL2
2.14 Transmission chain of VDSL2 connections

Complete network architecture for high-speed data transmission and Internet access via xDSL is shown in next figure.

Transmission chain of VDSL2 connections.

Network architecture can be in general divided into next three parts:

- CPN (Customer Premises Network),
- NAP (Network Access Provider),
- NSP (Network Service Provider).

A distinctive feature of the concept is referred to the division between the ISP and service providers. Both roles can perform a single entity, but in connection with a variety of services and competitive environment in telecommunications is useful to separate the roles.

In the concept of subscriber network can include everything follows the terminating point of the network access provider (usually a telecommunications outlet), i.e. the terminal equipment, terminals, local data networks and LAN.

Provider NAP operates a technology for the physical transmission of signals from subscribers to the telecommunications nodes. In the case of VDSL2 connections NAP is composed of copper symmetrical pairs (metallic conductions) that result from CPN and terminating in access multiplexers DSLAM. Multiplexers ISP connects to its own core network, of which there is a connection to the service provider.

Sources of data that is transmitted through the NAP, located in the network service provider NSP. For example, it may be just one company, typically a company operating an archive of TV programs, or may be formed by NSP de facto global network Internet.