What is DID – Direct Inward Dialing?

DID stands for – Direct Inward Dialing (or DDIDirect Dialling Inward in Europe) is a feature offered by telephone companies for use with their customers’ PBX system, whereby the telephone company allocates a range of telephone numbers associated with one or more phone lines. DID allows a company to assign a personal number to each employee, without requiring a separate physical phone line for each to connect to the PBX. This way, telephony traffic can be split up and managed more easily.

For example, if an organisation has 25 employees and each employee has a separate telephone number or extension, within its physical location, the organisation can rent 10 physical trunk lines from the telephone company that will allow 10 phone calls to take place simultaneously. Others would have to wait for an available line and anyone dialling into the system while all 10 lines are in use would get either a busy signal or be directed to a voicemail system. A DID system can be used for fax and voice transmissions.

DID works similarly for VoIP communications. To allow PSTN users to directly reach VoIP users, DID numbers are assigned to a gateway. The gateway connects the PSTN (public switched telephone network) to the VoIP network, routing and translating calls between the two networks for the VoIP user. Calls from the PSTN will be directed to the VoIP user who holds the corresponding DID number. DID requires that you purchase an ISDN or digital line and ask the telephone company to assign a range of numbers. You will then need DID capable equipment at your premises which consists of BRI, E1 or T1 cards or Gateways.

Related Blogs

An Overview Of Microsoft Teams Calling Security

In today's ever-evolving digital environment, the significance of secure communication cannot be overstated, particularly for businesses. The protected exchange of confidential data is paramount, and thanks to its robust security protocols, Microsoft Teams emerges as a standout solution.   In this article, we will explore the vital security features that Microsoft Teams...

30/01/2024 | Read more

The Ultimate Guide To Microsoft Teams Calling

In the ever-evolving landscape of business communication, digital technology has revolutionised how we connect, collaborate, and carry out our daily operations. Among the various innovations, Microsoft Teams phone calling has emerged as a beacon of transformation, offering a seamless and integrated communication experience. This article explores the heart of Microsoft Teams phone...

12/12/2023 | Read more

Proven Communication Strategies for Remote Teams

As a result of the pandemic, more and more businesses have embraced remote working, bringing about a major change in our work culture. This trend is altering how teams interact and collaborate, highlighting the importance of effective communication as a key factor for success.   Common Challenges Of Remote Communication Communication can...

02/11/2023 | Read more