Editing Digital subscriber line (section)

==Typical setup==
[[File:Outdoor DSLAM.JPG|thumb|Example of a DSLAM from 2006]]
On the customer side, a DSL modem is hooked up to a phone line. The telephone company connects the other end of the line to a [[DSLAM]], which concentrates a large number of individual DSL connections into a single box. The DSLAM cannot be located too far from the customer because of [[attenuation]] between the DSLAM and the user's DSL modem. It is common for a few residential blocks to be connected to one DSLAM.

[[File:Dsl schematic.svg|thumb|center|600px|DSL Connection schematic]]
The above figure is a schematic of a simple DSL connection (in blue). The right side shows a DSLAM residing in the telephone company's telephone exchange. The left side shows the customer premises equipment with an optional router. The router manages a [[local area network]] which connects PCs and other local devices. The customer may opt for a modem that contains both a router and wireless access. This option (within the dashed bubble) often simplifies the connection.

===Exchange equipment===
[[File:DSL filters at a telephone central office.jpg|thumb|Older stand-alone ADSL filter and splitter banks at a telephone exchange]]
At the exchange, a [[digital subscriber line access multiplexer]] (DSLAM) [[Electrical termination|terminate]]s the DSL circuits and aggregates them, where they are [[handoff|handed off]] to other networking transports such as a  PON network or Ethernet. The DSLAM terminates all connections and recovers the original digital information. In the case of ADSL, the voice component is also separated at this step, either by a filter or splitter integrated in the DSLAM or by specialized filtering equipment installed before it.<ref>{{cite book | url=https://books.google.com/books?id=Jjkd74jY47oC&dq=dsl+filter+rack&pg=PA7 | title=Implementation and Applications of DSL Technology | isbn=9781420013078 | last1=Golden | first1=Philip | last2=Dedieu | first2=Herve | last3=Jacobsen | first3=Krista S. | date=26 October 2007 | publisher=CRC Press }}</ref> Load coils in phone lines, used for extending their range in rural areas, must be removed to allow DSL to operate as they only allow frequencies of up to 4000 Hz to pass through phone cables.<ref>{{cite book | url=https://books.google.com/books?id=mpHoYDO9FH4C&dq=dsl+voice+grade&pg=PA8 | title=ISDN User Newsletter | publisher=Information Gatekeepers }}</ref><ref>{{cite book | url=https://books.google.com/books?id=_zbHY0sLCKUC&dq=dsl+load+coil&pg=PA34 | isbn=978-1-58705-087-9 | title=End-to-end DSL Architectures | date=2003 | publisher=Cisco Press }}</ref><ref>{{cite book | url=https://books.google.com/books?id=3Dn9KlIVM_EC&dq=dsl+load+coil&pg=PA340 | isbn=978-1-58705-119-7 | title=Internetworking Technologies Handbook | date=2004 | publisher=Cisco Press }}</ref>

===Customer equipment===
[[File:Dsl modem schematic.svg|thumb|center|400px|DSL Modem schematic]]

The customer end of the connection consists of a [[DSL modem]]. This converts data between the digital signals used by computers and the analog [[voltage]] signal of a suitable frequency range which is then applied to the phone line.

In some DSL variations (for example, [[HDSL]]), the modem connects directly to the computer via a serial interface, using protocols such as [[Ethernet]] or [[V.35 (recommendation)|V.35]]. In other cases (particularly ADSL), it is common for the customer equipment to be integrated with higher-level functionality, such as routing, firewalling, or other application-specific hardware and software. In this case, the equipment is referred to as a gateway.

Most DSL technologies require the installation of appropriate [[DSL filter]]s at the customer's premises to separate the DSL signal from the low-frequency voice signal. The separation can take place either at the [[demarcation point]], or with filters installed at the [[Telephone jack and plug|telephone outlets]] inside the customer premises. It is possible for a DSL gateway to integrate the filter, and allow telephones to connect through the gateway.

Modern DSL [[gateway (telecommunications)|gateways]] often integrate routing and other functionality. The system boots, synchronizes the DSL connection and finally establishes the internet IP services and connection between the local network and the service provider, using protocols such as [[DHCP]] or [[PPPoE]].