What is Direct Inward Dialing?

2020-10-14 11:49:01
14155
0

Traditionally, companies have used a direct inward dialing service to route calls through an on-premises PBX directly to the internal phone number of an employee. It allows the company to use one physical trunk line to connect multiple employees. 

Direct Inward Dialing, or DID, is a service offered by a local exchange carrier (LEC) that allows a PBX to route calls directly to extensions. It eliminates a voice menu or IVR and enables callers to directly reach a specific employee. A telephone number that is used for direct inward dialing is also called a DID. 

From On-Premise to Cloud

Until the late twentieth century, phone lines were expensive. Businesses deployed private branch exchange (PBX) telephone systems on-premises to optimize their utilization.

Instead of purchasing phone lines for every employee, businesses would just get one number for the office. Every employee would be assigned a private extension. A caller would dial the office number, wait for a prompt from the PBX, and then dial an extension number to get to the right employee. 

When DID service was introduced, companies could assign their employees their own unique phone numbers instead of sharing a company number. Calls could be routed over shared trunk lines connecting the PBX with the local exchange carrier (LEC) central office.

Businesses purchase a block of phone numbers from a LEC along with the DID service. On inbound calls, the service uses signaling to deliver the last four digits of the dialed number to the PBX. It enables the PBX to route the call to the proper extension. 

Today PBXs have moved to the cloud or become a function of CPaaS platforms like Voximplant. The term ‘DID’ doesn’t mean as much as it used to. Each phone number purchased on the Voximplant platform can turn into a DID with a few lines of code.

How does Voximplant Leverage DIDs?

With the Voximplant platform, you can implement DID-like functionality and route callers directly to any user including non-PSTN endpoints. 

A traditional phone-to-phone is split into ‘two legs’: from the first phone to the Voximplant cloud and then to the second endpoint. The audio streams are connected via cloud-based JavaScript code. Here’s how calls go through the Voximplant cloud.

See our documentation to find out how to call PSTN and SIP endpoints.

Sign Up for a free Voximplant developer account or talk to our experts

Add your comment

Name*
Email*
Message

Your comment has been added and will be published after moderation.

Recommended posts

What is a No-code Contact Center?

What is a No-code Contact Center?

If you’re involved in evaluating cloud contact center services, you’ve likely recognized two distinct categories and a big difference in the amount of technical expertise required to implement them. You’re attracted to the ease of use offered by contact center as service (CCaaS) offerings, but their fixed functionality doesn’t fit your business needs. In contrast, a cloud contact center built on a communications platform as a service (CPaaS) offering provides unlimited flexibility, but requires expensive software development resources to build a complete solution.

An Introduction to Selective Forwarding Units

An Introduction to Selective Forwarding Units

Adding peer-to-peer communications to an application is relatively straight-forward. Developers can leverage WebRTC APIs or a CPaaS service to quickly add real time voice and video to their web or mobile app. But, what if you want to hold a meeting with more than two people? How can you leverage powerful WebRTC APIs to build a multi party conferencing application?

Where CPaaS Deploy their Networks - a Comparison

Where CPaaS Deploy their Networks - a Comparison

A couple weeks ago, Amazon Web Services (AWS) experienced an outage in its US-EAST-1 region. As so many services rely on AWS, this outage had a broader impact, causing outages and various issues with Amazon’s own Ring services, online retailers, and even the New York City MTA. In addition, a couple major Communications Platform as a Service (CPaaS) providers also reported issues (Voximplant was not impacted), potentially impacting the communications of many of their customers.  With this in mind, now is a good time to look at how CPaaS offers leverage public cloud infrastructure and review the factors involved in providing reliable, high quality communications services. In this post we will review the public cloud infrastructure used by several major CPaaS vendors and discuss the implications of their choices.