What is an ADSL Router

Definition

An ADSL router is also known as a DSL modem. The router is used to connect the computer to the DSL phone line for using the ADSL service. Some countries also use the term NTBBA, which stands for Network Termination BroadBand Access. There are some ADSL routers that are also capable of sharing a single Internet connection with a group of computers on a network. This system is also known as the residential gateway.

The ATU-R

Every ADSL router has a functional block called ADSL Terminal Unit-Remote, or the ATU-R (transceiver). The ATU-R is responsible for functions like demodulation, modulation, and framing. There are other functional blocks as well that perform specific functions like IP routing and bridging. The interfaces for the ADSL router are either Ethernet or USB. The ADSL modem might have been assigned an IP address from the beginning for management purposes, though an ADSL router that works as a bridge does not need an IP address.

Router Placement

The ADSL router in most cases is not placed inside the computer. It is connected to the computer's port, like the USB port or Ethernet. Voiceband modems, on the other hand, are placed inside the computer. The Windows operating systems, as well as other operating systems, do not recognize the ADSL router. There is no property sheet or an internal method to manage them. The reason is that the computer and the transceiver are separate nodes in the LAN. The transceiver (ADSL modem) is not controlled by the computer, unlike the keyboard and mouse.

Configuration

The ADSL router can be configured manually by opening a Web page in the browser. Some routers require no configuration because they are incorporated into the physical layer of the network. The frequencies of the router range between 25 kHz and 1 MHz. Hence, it does not interfere with the voice service, whose bandwidth ranges between 0 and 4 KHz. Hence, you can talk on the phone even if you have powered on the router and are using the Internet. Voiceband modems, on the other hand, work on the same frequency as the telephone; hence, they might interfere with the voice service.

Speed

The speed of the ADSL router varies and depends on the plan you have purchased from your ISP. Speeds vary from hundreds of kilobits per second to megabits per second. The ADSL router exchanges data with the wired DSLAM that is connected to the Internet. The router is configured for particular protocols only and might not work even on another line in the same house or company.

Hardware Components

The hardware components of the ADSL router are a transformer and a data connection such as Ethernet or USB. Also required are the digital data pump, a line driver, a filter, and a micro controller.


Posted by: Wasim Javed