Dialed Number Identification Service (DNIS) is a service sold by telecommunications companies to corporate clients that lets them determine which telephone number was dialed by a customer. This is useful in determining how to answer an inbound call. For example, a company may have a different toll free number for each product line it sells. If a call center is handling calls for multiple product...

Direct Inward Dialing (DID, also called DDI in Europe) is a feature offered by telephone companies for use with their customers' PBX system, whereby the telephone company (telco) allocates a range of numbers all connected to their customer's PBX. As calls are presented to the PBX, the number that the caller dialed is also given, so the PBX can route the call to the desired person or bureau...

 Digital signal 1 (DS1, also known as T1, sometimes "DS-1") is a T-carrier signaling scheme devised by Bell Labs.[1] DS1 is a widely used standard in telecommunications in North America and Japan to transmit voice and data between devices. E1 is used in place of T1 outside of North America and Japan. Technically, DS1 is the transmission protocol used over a physical T1 line; however...

DSL or xDSL, is a family of technologies that provide digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop, although in recent years, many[attribution needed] have adopted digital subscriber line as a more marketing-friendly term for the most popular version of consumer-ready DSL, ADSL. Typically, upload speed is lower than ...

Direct Inward Dialing (DID, also called DDI in Europe) is a feature offered by telephone companies for use with their customers' PBX system, whereby the telephone company (telco) allocates a range of numbers all connected to their customer's PBX. As calls are presented to the PBX, the number that the caller dialed is also given, so the PBX can route the call to the desired person or bureau...

Dialed Number Identification Service (DNIS) is a service sold by telecommunications companies to corporate clients that lets them determine which telephone number was dialed by a customer. This is useful in determining how to answer an inbound call. For example, a company may have a different toll free number for each product line it sells. If a call center is handling calls for multiple product...

Digital Signal Level 3 (DS3) is a term coined by AT&T to describe a digital transmission line framing 28 DS1 lines or 672 separate 64 kbps channels into one communications path. A DS3 line provides a conduit for any combination of data, voice or video applications. The versatility of DS3 makes it ideal for data-intensive users with large backbone applications or private networks requiring channelized transport.