How to Make Phone Calls Using a DSL Line

When you choose DSL as your online access method, you can run your broadband service through the phone wiring in your home or office with no need for additional cabling or connections other than a plug-in filter. DSL may offer slower connections than other options, such as cable broadband or fiber optic service, but it can provide a thrifty alternative. How you make telephone calls on a DSL line depends on the type of DSL you have and the way you obtain your dial-tone service.

The distance between your location and the phone company's central office determines whether you can opt for DSL service and how fast it can be, with shorter distances promising faster service. Most residential DSL connections operate asynchronously, which means that they offer faster speeds for downloaded data than for files you want to send or upload. This setup favors Web browsing over file transmission. Telephone companies typically charge more for faster connections and add a premium for synchronous service, which provides matched download and upload speeds. In most cases, DSL data can flow over the same phone lines that carry your phone conversations and fax transmissions.

To use a phone line for DSL service and telephone calls, you need to install a filter that allows the DSL bandwidth to share the line with the signals that carry your phone conversations or fax transmissions. Without a filter, your Internet connection may disconnect or lose connection speed dramatically each time you pick up the phone to make a call, and you may hear unusual noise on the phone line. The simplest filters to install consist of small devices that plug in to your phone jacks and extend the outlets to your telephone sets or fax machine. Leave these filters off the outlet into which you plug your DSL modem.

"Naked" DSL -- also called dry-loop or freestanding DSL -- consists of a DSL connection that doesn't include dial-tone service, typically offered at a much lower cost than DSL that includes a phone line. Not all phone companies provide this form of DSL, so before you decide to opt for it, verify that it's available in your city and at your location. Because VoIP phone service uses your DSL bandwidth to make phone calls, you need a data connection, not a phone line with dial tone, to make VoIP calls. You also can use VoIP options on a DSL line that supports voice service, enabling you to add a second phone line. VoIP providers include BasicTalk, Ooma and Vonage (see Resources).

DSL lines that include dial tone accept the same telephones you use with traditional voice-only phone service. If you decide to opt for VoIP service instead of or in addition to voice-over-data DSL, you'll need to use a VoIP adapter or a specially designed VoIP phone that won't work if you plug it in to a regular phone jack. Because VoIP calls use up part of the bandwidth you otherwise dedicate to online activities, you may notice a drop in your Internet speed if you set up multiple VoIP phones and use more than one of them at the same time, just as sharing a DSL connection for data drops the online speed for each user.